* [PATCH 1/3] cr: add generic LSM c/r support (v4)
@ 2009-10-02 3:49 ` Serge E. Hallyn
0 siblings, 0 replies; 22+ messages in thread
From: Serge E. Hallyn @ 2009-10-02 3:49 UTC (permalink / raw)
To: Linux Containers
Cc: linux-security-module, SELinux, Casey Schaufler, Stephen Smalley
(wasn't versioning the patchsets before, so randomly pick 4 as
the version for this patchset...)
Documentation/checkpoint/readme.txt begins:
"""
Application checkpoint/restart is the ability to save the state
of a running application so that it can later resume its execution
from the time at which it was checkpointed.
"""
This patch adds generic support for c/r of LSM credentials. Support
for Smack and SELinux (and TOMOYO if appropriate) will be added later.
Capabilities is already supported through generic creds code.
This patch supports ipc_perm, msg_msg, cred (task) and file ->security
fields. Inodes, superblocks, netif, and xfrm currently are restored
not through sys_restart() but through container creation, and so the
security fields should be done then as well. Network should be added
when network c/r is added.
Briefly, all security fields must be exported by the LSM as a simple
null-terminated string. They are checkpointed through the
security_checkpoint_obj() helper, because we must pass it an extra
sectype field. Splitting SECURITY_OBJ_SEC into one type per object
type would not work because, in Smack, one void* security is used for
all object types. But we must pass the sectype field because in
SELinux a different type of structure is stashed in each object type.
The RESTART_KEEP_LSM flag indicates that the LSM should
attempt to reuse checkpointed security labels. It is always
invalid when the LSM at restart differs from that at checkpoint.
It is currently only usable for capabilities.
(For capabilities, restart without RESTART_KEEP_LSM is technically
not implemented. There actually might be a use case for that,
but the safety of it is dubious so for now we always re-create
checkpointed capability sets whether RESTART_KEEP_LSM is
specified or not)
The result of applying this patchset can be seen at
http://git.kernel.org/gitweb.cgi?p=linux/kernel/git/sergeh/linux-cr.git;a=shortlog;h=ckpt-v18-hallyn.lsm3
Changelog:
sep 3: fix memory leak on LSM restore error path
Sep 3: provide 2 hooks, may_restart and checkpoint_header, to facilitate
an LSM tracking policy changes.
sep 10: merge RESTART_KEEP_LSM patch with basic LSM c/r
support patches.
sep 10: rename security_xyz_get_ctx() to security_xyz_checkpoint(),
in order to avoid confusing with the various other 'context'
helpers in the security_ namespace, relating to secids and
sysfs xattrs.
sep 10: pass context file to security_cred_restore. SELinux will
want the file's security context to authorize it as an
entrypoint for the new process context.
oct 01: roll up some generic c/r debug hunks from selinux patch.
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Stephen Smalley <sds@epoch.ncsc.mil>
Cc: Casey Schaufler <casey@schaufler-ca.com>
---
Documentation/checkpoint/readme.txt | 25 +++++
checkpoint/checkpoint.c | 11 ++
checkpoint/files.c | 34 +++++++
checkpoint/objhash.c | 93 +++++++++++++++++
checkpoint/process.c | 20 +++-
checkpoint/restart.c | 25 +++++
checkpoint/sys.c | 22 ++++
include/linux/checkpoint.h | 7 +-
include/linux/checkpoint_hdr.h | 24 +++++-
include/linux/checkpoint_types.h | 9 ++
include/linux/security.h | 188 +++++++++++++++++++++++++++++++++++
ipc/checkpoint.c | 34 +++++--
ipc/checkpoint_msg.c | 26 +++++-
ipc/checkpoint_sem.c | 4 +-
ipc/checkpoint_shm.c | 4 +-
ipc/util.h | 6 +-
kernel/cred.c | 20 ++++-
security/capability.c | 74 ++++++++++++++
security/security.c | 131 ++++++++++++++++++++++++
19 files changed, 731 insertions(+), 26 deletions(-)
diff --git a/Documentation/checkpoint/readme.txt b/Documentation/checkpoint/readme.txt
index 571c469..8ec5850 100644
--- a/Documentation/checkpoint/readme.txt
+++ b/Documentation/checkpoint/readme.txt
@@ -333,6 +333,31 @@ So that's why we don't want CAP_SYS_ADMIN required up-front. That way
we will be forced to more carefully review each of those features.
However, this can be controlled with a sysctl-variable.
+LSM
+===
+
+Security modules use custom labels on subjects and objects to
+further mediate access decisions beyond DAC controls. When
+checkpoint applications, these labels are [ work in progress ]
+checkpointed along with the objects. At restart, the
+RESTART_KEEP_LSM flag tells the kernel whether re-created objects
+whould keep their checkpointed labels, or get automatically
+recalculated labels. Since checkpointed labels will only make
+sense to the same LSM which was active at checkpoint time,
+sys_restart() with the RESTART_KEEP_LSM flag will fail with
+-EINVAL if the LSM active at restart is not the same as that
+active at checkpoint. If RESTART_KEEP_LSM is not specified,
+then objects will be given whatever default labels the LSM and
+their optional policy decide. Of course, when RESTART_KEEP_LSM
+is specified, the LSM may choose a different label than the
+checkpointed one, or fail the entire restart if the caller
+does not have permission to create objects with the checkpointed
+label.
+
+It should always be safe to take a checkpoint of an application
+under LSM_1, and restart it without the RESTART_KEEP_LSM flag
+under LSM_2.
+
Kernel interfaces
=================
diff --git a/checkpoint/checkpoint.c b/checkpoint/checkpoint.c
index 1eeb557..6722035 100644
--- a/checkpoint/checkpoint.c
+++ b/checkpoint/checkpoint.c
@@ -25,6 +25,7 @@
#include <linux/magic.h>
#include <linux/hrtimer.h>
#include <linux/deferqueue.h>
+#include <linux/security.h>
#include <linux/checkpoint.h>
#include <linux/checkpoint_hdr.h>
@@ -351,6 +352,16 @@ static int checkpoint_write_header(struct ckpt_ctx *ctx)
if (ret < 0)
return ret;
+ memset(ctx->lsm_name, 0, SECURITY_NAME_MAX + 1);
+ strlcpy(ctx->lsm_name, security_get_lsm_name(), SECURITY_NAME_MAX + 1);
+ ret = ckpt_write_buffer(ctx, ctx->lsm_name, SECURITY_NAME_MAX + 1);
+ if (ret < 0)
+ return ret;
+
+ ret = security_checkpoint_header(ctx);
+ if (ret < 0)
+ return ret;
+
return checkpoint_write_header_arch(ctx);
}
diff --git a/checkpoint/files.c b/checkpoint/files.c
index 27e29a0..570facb 100644
--- a/checkpoint/files.c
+++ b/checkpoint/files.c
@@ -145,6 +145,19 @@ static int scan_fds(struct files_struct *files, int **fdtable)
return n;
}
+#ifdef CONFIG_SECURITY
+int checkpoint_file_security(struct ckpt_ctx *ctx, struct file *file)
+{
+ return security_checkpoint_obj(ctx, file->f_security,
+ CKPT_SECURITY_FILE);
+}
+#else
+int checkpoint_file_security(struct ckpt_ctx *ctx, struct file *file)
+{
+ return -EOPNOTSUPP;
+}
+#endif
+
int checkpoint_file_common(struct ckpt_ctx *ctx, struct file *file,
struct ckpt_hdr_file *h)
{
@@ -159,6 +172,16 @@ int checkpoint_file_common(struct ckpt_ctx *ctx, struct file *file,
if (h->f_credref < 0)
return h->f_credref;
+ h->f_secref = checkpoint_file_security(ctx, file);
+ if (h->f_secref == -EOPNOTSUPP)
+ h->f_secref = -1;
+ else if (h->f_secref < 0)
+ return h->f_secref;
+
+ ckpt_debug("file %s credref %d secref %d",
+ file->f_dentry->d_name.name, h->f_credref,
+ h->f_secref);
+
/* FIX: need also file->f_owner, etc */
return 0;
@@ -507,6 +530,17 @@ int restore_file_common(struct ckpt_ctx *ctx, struct file *file,
put_cred(file->f_cred);
file->f_cred = get_cred(cred);
+ if ((ctx->uflags & RESTART_KEEP_LSM) && (h->f_secref != -1)) {
+ struct ckpt_stored_lsm *l = ckpt_obj_fetch(ctx, h->f_secref,
+ CKPT_OBJ_SEC);
+ if (IS_ERR(l))
+ return PTR_ERR(l);
+
+ ret = security_file_restore(file, l->string);
+ if (ret)
+ return ret;
+ }
+
/* safe to set 1st arg (fd) to 0, as command is F_SETFL */
ret = vfs_fcntl(0, F_SETFL, h->f_flags & CKPT_SETFL_MASK, file);
if (ret < 0)
diff --git a/checkpoint/objhash.c b/checkpoint/objhash.c
index f84388d..58ff040 100644
--- a/checkpoint/objhash.c
+++ b/checkpoint/objhash.c
@@ -16,6 +16,7 @@
#include <linux/file.h>
#include <linux/fdtable.h>
#include <linux/sched.h>
+#include <linux/kref.h>
#include <linux/ipc_namespace.h>
#include <linux/user_namespace.h>
#include <linux/checkpoint.h>
@@ -285,6 +286,89 @@ static int obj_tty_users(void *ptr)
return atomic_read(&((struct tty_struct *) ptr)->kref.refcount);
}
+static void obj_free_sec(struct kref *kref)
+{
+ struct ckpt_stored_lsm *s = container_of(kref, struct ckpt_stored_lsm,
+ kref);
+ kfree(s->string);
+ kfree(s);
+}
+
+static int obj_sec_grab(void *ptr)
+{
+ struct ckpt_stored_lsm *s = ptr;
+ kref_get(&s->kref);
+ return 0;
+}
+
+static void obj_sec_drop(void *ptr, int lastref)
+{
+ struct ckpt_stored_lsm *s = ptr;
+ kref_put(&s->kref, obj_free_sec);
+}
+
+static int do_checkpoint_security(struct ckpt_ctx *ctx,
+ const struct ckpt_stored_lsm *l)
+{
+ int ret, len;
+ struct ckpt_hdr_lsm *h;
+
+ len = strlen(l->string);
+ if (len > PAGE_SIZE - sizeof(*h))
+ return -E2BIG;
+ h = ckpt_hdr_get_type(ctx, sizeof(*h)+len+1, CKPT_HDR_SEC);
+ if (!h)
+ return -ENOMEM;
+ h->len = len;
+ h->sectype = l->sectype;
+ strncpy(h->string, l->string, len);
+ h->string[len] = '\0';
+ ret = ckpt_write_obj(ctx, &h->h);
+ ckpt_hdr_put(ctx, h);
+ return ret;
+}
+
+static int checkpoint_security(struct ckpt_ctx *ctx, void *ptr)
+{
+ return do_checkpoint_security(ctx, (struct ckpt_stored_lsm *) ptr);
+}
+
+static struct ckpt_stored_lsm *do_restore_security(struct ckpt_ctx *ctx)
+{
+ struct ckpt_hdr_lsm *h;
+ struct ckpt_stored_lsm *l;
+
+ h = ckpt_read_buf_type(ctx, PAGE_SIZE, CKPT_HDR_SEC);
+ if (IS_ERR(h))
+ return (struct ckpt_stored_lsm *)h;
+ if (h->len > h->h.len - sizeof(struct ckpt_hdr) ||
+ h->len > PAGE_SIZE) {
+ ckpt_hdr_put(ctx, h);
+ return ERR_PTR(-EINVAL);
+ }
+ l = kzalloc(sizeof(*l), GFP_KERNEL);
+ if (!l) {
+ ckpt_hdr_put(ctx, h);
+ return ERR_PTR(-ENOMEM);
+ }
+ l->string = kzalloc(h->len + 1, GFP_KERNEL);
+ if (!l->string) {
+ kfree(l);
+ ckpt_hdr_put(ctx, h);
+ return ERR_PTR(-ENOMEM);
+ }
+ kref_init(&l->kref);
+ l->sectype = h->sectype;
+ strncpy(l->string, h->string, h->len);
+ ckpt_hdr_put(ctx, h);
+ return l;
+}
+
+static void *restore_security(struct ckpt_ctx *ctx)
+{
+ return (void *) do_restore_security(ctx);
+}
+
static struct ckpt_obj_ops ckpt_obj_ops[] = {
/* ignored object */
{
@@ -433,6 +517,15 @@ static struct ckpt_obj_ops ckpt_obj_ops[] = {
.checkpoint = checkpoint_tty,
.restore = restore_tty,
},
+ /* LSM security labels */
+ {
+ .obj_name = "LSM",
+ .obj_type = CKPT_OBJ_SEC,
+ .ref_drop = obj_sec_drop,
+ .ref_grab = obj_sec_grab,
+ .checkpoint = checkpoint_security,
+ .restore = restore_security,
+ },
};
diff --git a/checkpoint/process.c b/checkpoint/process.c
index 5ba64f0..ed7896c 100644
--- a/checkpoint/process.c
+++ b/checkpoint/process.c
@@ -581,11 +581,15 @@ static int restore_task_creds(struct ckpt_ctx *ctx)
realcred = ckpt_obj_fetch(ctx, h->cred_ref, CKPT_OBJ_CRED);
if (IS_ERR(realcred)) {
+ ckpt_debug("Error %ld fetching readlcred (ref %d)",
+ PTR_ERR(realcred), h->cred_ref);
ret = PTR_ERR(realcred);
goto out;
}
ecred = ckpt_obj_fetch(ctx, h->ecred_ref, CKPT_OBJ_CRED);
if (IS_ERR(ecred)) {
+ ckpt_debug("Error %ld fetching ecred (ref %d)",
+ PTR_ERR(ecred), h->ecred_ref);
ret = PTR_ERR(ecred);
goto out;
}
@@ -593,6 +597,7 @@ static int restore_task_creds(struct ckpt_ctx *ctx)
ctx->ecred = ecred;
out:
+ ckpt_debug("Returning %d.", ret);
ckpt_hdr_put(ctx, h);
return ret;
}
@@ -608,14 +613,21 @@ static int restore_task_objs(struct ckpt_ctx *ctx)
* referenced. See comment in checkpoint_task_objs.
*/
ret = restore_task_creds(ctx);
- if (!ret)
- ret = restore_task_ns(ctx);
- if (ret < 0)
+ if (ret) {
+ ckpt_debug("restore_task_creds returned %d", ret);
+ return ret;
+ }
+ ret = restore_task_ns(ctx);
+ if (ret) {
+ ckpt_debug("restore_task_ns returned %d", ret);
return ret;
+ }
h = ckpt_read_obj_type(ctx, sizeof(*h), CKPT_HDR_TASK_OBJS);
- if (IS_ERR(h))
+ if (IS_ERR(h)) {
+ ckpt_debug("Error fetching task obj");
return PTR_ERR(h);
+ }
ret = restore_obj_file_table(ctx, h->files_objref);
ckpt_debug("file_table: ret %d (%p)\n", ret, current->files);
diff --git a/checkpoint/restart.c b/checkpoint/restart.c
index b12c8bd..bba2b45 100644
--- a/checkpoint/restart.c
+++ b/checkpoint/restart.c
@@ -457,6 +457,31 @@ static int restore_read_header(struct ckpt_ctx *ctx)
if (ret < 0)
goto out;
+ ret = _ckpt_read_buffer(ctx, ctx->lsm_name, SECURITY_NAME_MAX + 1);
+ if (ret < 0)
+ goto out;
+ if (ctx->uflags & RESTART_KEEP_LSM) {
+ char *cur = security_get_lsm_name();
+ if (strncmp(cur, ctx->lsm_name, SECURITY_NAME_MAX + 1) != 0) {
+ pr_warning("c/r: checkpointed LSM %s, current is %s.\n",
+ ctx->lsm_name, cur);
+ ret = -EINVAL;
+ goto out;
+ }
+ /* to be implemented later, per-lsm */
+ if (strcmp(ctx->lsm_name, "lsm_none") != 0 &&
+ strcmp(ctx->lsm_name, "default") != 0) {
+ pr_warning("c/r: RESTART_KEEP_LSM unsupported for %s\n",
+ ctx->lsm_name);
+ ret = -ENOSYS;
+ goto out;
+ }
+ }
+
+ ret = security_may_restart(ctx);
+ if (ret < 0)
+ goto out;
+
ret = restore_read_header_arch(ctx);
out:
kfree(uts);
diff --git a/checkpoint/sys.c b/checkpoint/sys.c
index 7604089..0a1e8a6 100644
--- a/checkpoint/sys.c
+++ b/checkpoint/sys.c
@@ -169,6 +169,28 @@ void *ckpt_hdr_get_type(struct ckpt_ctx *ctx, int len, int type)
return h;
}
+#define DUMMY_LSM_INFO "dummy"
+
+int ckpt_write_dummy_lsm_info(struct ckpt_ctx *ctx)
+{
+ return ckpt_write_obj_type(ctx, DUMMY_LSM_INFO,
+ strlen(DUMMY_LSM_INFO), CKPT_HDR_LSM_INFO);
+}
+
+/*
+ * ckpt_snarf_lsm_info
+ * If there is a CKPT_HDR_LSM_INFO field, toss it.
+ * Used when the current LSM doesn't care about this field.
+ */
+void ckpt_snarf_lsm_info(struct ckpt_ctx *ctx)
+{
+ struct ckpt_hdr *h;
+
+ h = ckpt_read_buf_type(ctx, CKPT_LSM_INFO_LEN, CKPT_HDR_LSM_INFO);
+ if (!IS_ERR(h))
+ ckpt_hdr_put(ctx, h);
+}
+
/*
* Helpers to manage c/r contexts: allocated for each checkpoint and/or
diff --git a/include/linux/checkpoint.h b/include/linux/checkpoint.h
index e403dd7..707f9fb 100644
--- a/include/linux/checkpoint.h
+++ b/include/linux/checkpoint.h
@@ -10,7 +10,7 @@
* distribution for more details.
*/
-#define CHECKPOINT_VERSION 2
+#define CHECKPOINT_VERSION 3
/* checkpoint user flags */
#define CHECKPOINT_SUBTREE 0x1
@@ -19,6 +19,7 @@
#define RESTART_TASKSELF 0x1
#define RESTART_FROZEN 0x2
#define RESTART_GHOST 0x4
+#define RESTART_KEEP_LSM 0x8
#ifdef __KERNEL__
#ifdef CONFIG_CHECKPOINT
@@ -48,7 +49,9 @@
#define RESTART_USER_FLAGS \
(RESTART_TASKSELF | \
RESTART_FROZEN | \
+ RESTART_KEEP_LSM | \
RESTART_GHOST)
+#define CKPT_LSM_INFO_LEN 200
extern int walk_task_subtree(struct task_struct *task,
int (*func)(struct task_struct *, void *),
@@ -62,6 +65,8 @@ extern void _ckpt_hdr_put(struct ckpt_ctx *ctx, void *ptr, int n);
extern void ckpt_hdr_put(struct ckpt_ctx *ctx, void *ptr);
extern void *ckpt_hdr_get(struct ckpt_ctx *ctx, int n);
extern void *ckpt_hdr_get_type(struct ckpt_ctx *ctx, int n, int type);
+extern int ckpt_write_dummy_lsm_info(struct ckpt_ctx *ctx);
+extern void ckpt_snarf_lsm_info(struct ckpt_ctx *ctx);
extern int ckpt_write_obj(struct ckpt_ctx *ctx, struct ckpt_hdr *h);
extern int ckpt_write_obj_type(struct ckpt_ctx *ctx,
diff --git a/include/linux/checkpoint_hdr.h b/include/linux/checkpoint_hdr.h
index 2ed523f..61ac537 100644
--- a/include/linux/checkpoint_hdr.h
+++ b/include/linux/checkpoint_hdr.h
@@ -58,6 +58,8 @@ enum {
CKPT_HDR_BUFFER,
CKPT_HDR_STRING,
CKPT_HDR_OBJREF,
+ CKPT_HDR_SEC,
+ CKPT_HDR_LSM_INFO,
CKPT_HDR_TREE = 101,
CKPT_HDR_TASK,
@@ -146,6 +148,7 @@ enum obj_type {
CKPT_OBJ_GROUPINFO,
CKPT_OBJ_SOCK,
CKPT_OBJ_TTY,
+ CKPT_OBJ_SEC,
CKPT_OBJ_MAX
};
@@ -189,10 +192,11 @@ struct ckpt_hdr_header {
__u64 uflags; /* uflags from checkpoint */
/*
- * the header is followed by three strings:
+ * the header is followed by four strings:
* char release[const.uts_release_len];
* char version[const.uts_version_len];
* char machine[const.uts_machine_len];
+ * char lsm_name[SECURITY_NAME_MAX + 1]
*/
} __attribute__((aligned(8)));
@@ -265,6 +269,8 @@ struct ckpt_hdr_cred {
__u32 gid, sgid, egid, fsgid;
__s32 user_ref;
__s32 groupinfo_ref;
+ __s32 sec_ref;
+ __u32 padding;
struct ckpt_capabilities cap_s;
} __attribute__((aligned(8)));
@@ -277,6 +283,16 @@ struct ckpt_hdr_groupinfo {
__u32 groups[0];
} __attribute__((aligned(8)));
+struct ckpt_hdr_lsm {
+ struct ckpt_hdr h;
+ __u8 sectype;
+ __u16 len;
+ /*
+ * This is followed by a string of size len+1,
+ * null-terminated
+ */
+ __u8 string[0];
+} __attribute__((aligned(8)));
/*
* todo - keyrings and LSM
* These may be better done with userspace help though
@@ -392,6 +408,8 @@ struct ckpt_hdr_file {
__s32 f_credref;
__u64 f_pos;
__u64 f_version;
+ __s32 f_secref;
+ __u32 f_padding;
} __attribute__((aligned(8)));
struct ckpt_hdr_file_generic {
@@ -634,6 +652,8 @@ struct ckpt_hdr_ipc_perms {
__u32 mode;
__u32 _padding;
__u64 seq;
+ __s32 sec_ref;
+ __u32 padding;
} __attribute__((aligned(8)));
struct ckpt_hdr_ipc_shm {
@@ -667,6 +687,8 @@ struct ckpt_hdr_ipc_msg_msg {
struct ckpt_hdr h;
__s32 m_type;
__u32 m_ts;
+ __s32 sec_ref;
+ __u32 padding;
} __attribute__((aligned(8)));
struct ckpt_hdr_ipc_sem {
diff --git a/include/linux/checkpoint_types.h b/include/linux/checkpoint_types.h
index b9393f4..6a2c9dc 100644
--- a/include/linux/checkpoint_types.h
+++ b/include/linux/checkpoint_types.h
@@ -21,6 +21,7 @@
#include <linux/fs.h>
#include <linux/ktime.h>
#include <linux/wait.h>
+#include <linux/security.h>
struct ckpt_stats {
int uts_ns;
@@ -42,6 +43,7 @@ struct ckpt_ctx {
struct task_struct *root_task; /* [container] root task */
struct nsproxy *root_nsproxy; /* [container] root nsproxy */
struct task_struct *root_freezer; /* [container] root task */
+ char lsm_name[SECURITY_NAME_MAX + 1]; /* security module at ckpt */
unsigned long kflags; /* kerenl flags */
unsigned long uflags; /* user flags */
@@ -82,6 +84,13 @@ struct ckpt_ctx {
struct ckpt_stats stats; /* statistics */
};
+/* stored on hashtable */
+struct ckpt_stored_lsm {
+ struct kref kref;
+ int sectype;
+ char *string;
+};
+
#endif /* __KERNEL__ */
#endif /* _LINUX_CHECKPOINT_TYPES_H_ */
diff --git a/include/linux/security.h b/include/linux/security.h
index 1f16eea..67f9c53 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -46,6 +46,10 @@
struct ctl_table;
struct audit_krule;
+#ifdef CONFIG_CHECKPOINT
+struct ckpt_ctx;
+#endif
+
/*
* These functions are in security/capability.c and are used
* as the default capabilities functions
@@ -574,6 +578,15 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
* created.
* @file contains the file structure to secure.
* Return 0 if the hook is successful and permission is granted.
+ * @file_checkpoint:
+ * Return a string representing the security context on a file.
+ * @security contains the security field.
+ * Returns a char* which the caller will free, or -error on error.
+ * @file_restore:
+ * Set a security context on a file according to the checkpointed context.
+ * @file contains the file.
+ * @ctx contains a string representation of the checkpointed context.
+ * Returns 0 on success, -error on failure.
* @file_free_security:
* Deallocate and free any security structures stored in file->f_security.
* @file contains the file structure being modified.
@@ -653,6 +666,17 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
* manual page for definitions of the @clone_flags.
* @clone_flags contains the flags indicating what should be shared.
* Return 0 if permission is granted.
+ * @cred_checkpoint:
+ * Return a string representing the security context on the task cred.
+ * @security contains the security field.
+ * Returns a char* which the caller will free, or -error on error.
+ * @cred_restore:
+ * Set a security context on a task cred according to the checkpointed
+ * context.
+ * @file contains the checkpoint file
+ * @cred contains the cred.
+ * @ctx contains a string representation of the checkpointed context.
+ * Returns 0 on success, -error on failure.
* @cred_free:
* @cred points to the credentials.
* Deallocate and clear the cred->security field in a set of credentials.
@@ -1101,6 +1125,19 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
* @ipcp contains the kernel IPC permission structure.
* @secid contains a pointer to the location where result will be saved.
* In case of failure, @secid will be set to zero.
+ * @ipc_checkpoint:
+ * Return a string representing the security context on the IPC
+ * permission structure.
+ * @security contains the security field.
+ * Returns a char* which the caller will free, or -error on error.
+ * @ipc_restore:
+ * Set a security context on a IPC permission structure according to
+ * the checkpointed context.
+ * @ipcp contains the IPC permission structure, which will have
+ * already been allocated and initialized when the IPC structure was
+ * created.
+ * @ctx contains a string representation of the checkpointed context.
+ * Returns 0 on success, -error on failure.
*
* Security hooks for individual messages held in System V IPC message queues
* @msg_msg_alloc_security:
@@ -1109,6 +1146,16 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
* created.
* @msg contains the message structure to be modified.
* Return 0 if operation was successful and permission is granted.
+ * @msg_msg_checkpoint:
+ * Return a string representing the security context on an msg_msg
+ * struct.
+ * @security contains the security field
+ * Returns a char* which the caller will free, or -error on error.
+ * @msg_msg_restore:
+ * Set msg_msg->security according to the checkpointed context.
+ * @msg contains the message structure to be modified.
+ * @ctx contains a string representation of the checkpointed context.
+ * Return 0 on success, -error on failure.
* @msg_msg_free_security:
* Deallocate the security structure for this message.
* @msg contains the message structure to be modified.
@@ -1320,6 +1367,28 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
* @secdata contains the security context.
* @seclen contains the length of the security context.
*
+ * Security hooks for Checkpoint/restart
+ * (In addition to *_checkpoint and *_restore)
+ *
+ * @may_restart:
+ * Authorize sys_restart().
+ * Note that all construction of kernel resources, credentials,
+ * etc is already authorized per the caller's credentials. This
+ * hook is intended for the LSM to make further decisions about
+ * a task not being allowed to restart at all, for instance if
+ * the policy has changed since checkpoint.
+ * @ctx is the checkpoint/restart context (see <linux/checkpoint_types.h>)
+ * Return 0 if allowed, <0 on error.
+ *
+ * @checkpoint_header:
+ * Optionally write out a LSM-specific checkpoint header. This is
+ * a chance to write out policy information, for instance. The same
+ * LSM on restart can then use the info in security_may_restart() to
+ * refuse restart (for instance) across policy changes.
+ * The info is to be written as a an object of type CKPT_HDR_LSM_INFO.
+ * @ctx is the checkpoint/restart context (see <linux/checkpoint_types.h>)
+ * Return 0 on success, <0 on error.
+ *
* Security hooks for Audit
*
* @audit_rule_init:
@@ -1463,6 +1532,8 @@ struct security_operations {
int (*file_permission) (struct file *file, int mask);
int (*file_alloc_security) (struct file *file);
+ char *(*file_checkpoint) (void *security);
+ int (*file_restore) (struct file *file, char *ctx);
void (*file_free_security) (struct file *file);
int (*file_ioctl) (struct file *file, unsigned int cmd,
unsigned long arg);
@@ -1483,6 +1554,8 @@ struct security_operations {
int (*dentry_open) (struct file *file, const struct cred *cred);
int (*task_create) (unsigned long clone_flags);
+ char *(*cred_checkpoint) (void *security);
+ int (*cred_restore) (struct file *file, struct cred *cred, char *ctx);
void (*cred_free) (struct cred *cred);
int (*cred_prepare)(struct cred *new, const struct cred *old,
gfp_t gfp);
@@ -1516,8 +1589,12 @@ struct security_operations {
int (*ipc_permission) (struct kern_ipc_perm *ipcp, short flag);
void (*ipc_getsecid) (struct kern_ipc_perm *ipcp, u32 *secid);
+ char *(*ipc_checkpoint) (void *security);
+ int (*ipc_restore) (struct kern_ipc_perm *ipcp, char *ctx);
int (*msg_msg_alloc_security) (struct msg_msg *msg);
+ char *(*msg_msg_checkpoint) (void *security);
+ int (*msg_msg_restore) (struct msg_msg *msg, char *ctx);
void (*msg_msg_free_security) (struct msg_msg *msg);
int (*msg_queue_alloc_security) (struct msg_queue *msq);
@@ -1556,6 +1633,11 @@ struct security_operations {
int (*secctx_to_secid) (const char *secdata, u32 seclen, u32 *secid);
void (*release_secctx) (char *secdata, u32 seclen);
+#ifdef CONFIG_CHECKPOINT
+ int (*may_restart) (struct ckpt_ctx *ctx);
+ int (*checkpoint_header) (struct ckpt_ctx *ctx);
+#endif
+
#ifdef CONFIG_SECURITY_NETWORK
int (*unix_stream_connect) (struct socket *sock,
struct socket *other, struct sock *newsk);
@@ -1721,6 +1803,8 @@ int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer
void security_inode_getsecid(const struct inode *inode, u32 *secid);
int security_file_permission(struct file *file, int mask);
int security_file_alloc(struct file *file);
+char *security_file_checkpoint(void *security);
+int security_file_restore(struct file *file, char *ctx);
void security_file_free(struct file *file);
int security_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
int security_file_mmap(struct file *file, unsigned long reqprot,
@@ -1736,6 +1820,8 @@ int security_file_send_sigiotask(struct task_struct *tsk,
int security_file_receive(struct file *file);
int security_dentry_open(struct file *file, const struct cred *cred);
int security_task_create(unsigned long clone_flags);
+char *security_cred_checkpoint(void *security);
+int security_cred_restore(struct file *file, struct cred *cred, char *ctx);
void security_cred_free(struct cred *cred);
int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp);
void security_commit_creds(struct cred *new, const struct cred *old);
@@ -1766,7 +1852,11 @@ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3,
void security_task_to_inode(struct task_struct *p, struct inode *inode);
int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag);
void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid);
+char *security_ipc_checkpoint(void *security);
+int security_ipc_restore(struct kern_ipc_perm *ipcp, char *ctx);
int security_msg_msg_alloc(struct msg_msg *msg);
+char *security_msg_msg_checkpoint(void *security);
+int security_msg_msg_restore(struct msg_msg *msg, char *ctx);
void security_msg_msg_free(struct msg_msg *msg);
int security_msg_queue_alloc(struct msg_queue *msq);
void security_msg_queue_free(struct msg_queue *msq);
@@ -1795,6 +1885,12 @@ int security_netlink_recv(struct sk_buff *skb, int cap);
int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen);
int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid);
void security_release_secctx(char *secdata, u32 seclen);
+#ifdef CONFIG_CHECKPOINT
+int security_may_restart(struct ckpt_ctx *ctx);
+int security_checkpoint_header(struct ckpt_ctx *ctx);
+#endif /* CONFIG_CHECKPOINT */
+
+char *security_get_lsm_name(void);
#else /* CONFIG_SECURITY */
struct security_mnt_opts {
@@ -1818,6 +1914,12 @@ static inline int security_init(void)
return 0;
}
+#define DEFAULT_LSM_NAME "lsm_none"
+static inline char *security_get_lsm_name(void)
+{
+ return DEFAULT_LSM_NAME;
+}
+
static inline int security_ptrace_may_access(struct task_struct *child,
unsigned int mode)
{
@@ -2202,6 +2304,19 @@ static inline int security_file_alloc(struct file *file)
return 0;
}
+static inline char *security_file_checkpoint(void *security)
+{
+ /* this shouldn't ever get called if SECURITY=n */
+ return ERR_PTR(-EINVAL);
+}
+
+static inline int security_file_restore(struct file *file, char *ctx)
+{
+ /* we're asked to recreate security contexts for an LSM which had
+ * contexts, but CONFIG_SECURITY=n now! */
+ return -EINVAL;
+}
+
static inline void security_file_free(struct file *file)
{ }
@@ -2266,6 +2381,20 @@ static inline int security_task_create(unsigned long clone_flags)
return 0;
}
+static inline char *security_cred_checkpoint(void *security)
+{
+ /* this shouldn't ever get called if SECURITY=n */
+ return ERR_PTR(-EINVAL);
+}
+
+static inline int security_cred_restore(struct file *file, struct cred *cred,
+ char *ctx)
+{
+ /* we're asked to recreate security contexts for an LSM which had
+ * contexts, but CONFIG_SECURITY=n now! */
+ return -EINVAL;
+}
+
static inline void security_cred_free(struct cred *cred)
{ }
@@ -2408,11 +2537,37 @@ static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
*secid = 0;
}
+static inline char *security_ipc_checkpoint(void *security)
+{
+ /* this shouldn't ever get called if SECURITY=n */
+ return ERR_PTR(-EINVAL);
+}
+
+static inline int security_ipc_restore(struct kern_ipc_perm *ipcp, char *ctx)
+{
+ /* we're asked to recreate security contexts for an LSM which had
+ * contexts, but CONFIG_SECURITY=n now! */
+ return -EINVAL;
+}
+
static inline int security_msg_msg_alloc(struct msg_msg *msg)
{
return 0;
}
+static inline char *security_msg_msg_checkpoint(void *security)
+{
+ /* this shouldn't ever get called if SECURITY=n */
+ return ERR_PTR(-EINVAL);
+}
+
+static inline int security_msg_msg_restore(struct msg_msg *msg, char *ctx)
+{
+ /* we're asked to recreate security contexts for an LSM which had
+ * contexts, but CONFIG_SECURITY=n now! */
+ return -EINVAL;
+}
+
static inline void security_msg_msg_free(struct msg_msg *msg)
{ }
@@ -2537,6 +2692,21 @@ static inline int security_secctx_to_secid(const char *secdata,
static inline void security_release_secctx(char *secdata, u32 seclen)
{
}
+
+#ifdef CONFIG_CHECKPOINT
+void ckpt_snarf_lsm_info(struct ckpt_ctx *ctx);
+int ckpt_write_dummy_lsm_info(struct ckpt_ctx *ctx);
+
+static inline int security_may_restart(struct ckpt_ctx *ctx)
+{
+ ckpt_snarf_lsm_info(ctx);
+ return 0;
+}
+static inline int security_checkpoint_header(struct ckpt_ctx *ctx)
+{
+ return ckpt_write_dummy_lsm_info(ctx);
+}
+#endif /* CONFIG_CHECKPOINT */
#endif /* CONFIG_SECURITY */
#ifdef CONFIG_SECURITY_NETWORK
@@ -2997,5 +3167,23 @@ static inline void free_secdata(void *secdata)
{ }
#endif /* CONFIG_SECURITY */
+#ifdef CONFIG_CHECKPOINT
+#define CKPT_SECURITY_MSG_MSG 1
+#define CKPT_SECURITY_IPC 2
+#define CKPT_SECURITY_FILE 3
+#define CKPT_SECURITY_CRED 4
+#define CKPT_SECURITY_MAX 4
+
+#ifdef CONFIG_SECURITY
+int security_checkpoint_obj(struct ckpt_ctx *ctx, void *security,
+ unsigned sectype);
+#else
+static inline int security_checkpoint_obj(struct ckpt_ctx *ctx, void *security,
+ unsigned sectype)
+{ return -1; }
+#endif /* CONFIG_SECURITY */
+
+#endif /* CONFIG_CHECKPOINT */
+
#endif /* ! __LINUX_SECURITY_H */
diff --git a/ipc/checkpoint.c b/ipc/checkpoint.c
index 8e6e9ba..c0d3f13 100644
--- a/ipc/checkpoint.c
+++ b/ipc/checkpoint.c
@@ -31,7 +31,8 @@ static char *ipc_ind_to_str[] = { "sem", "msg", "shm" };
* Checkpoint
*/
-int checkpoint_fill_ipc_perms(struct ckpt_hdr_ipc_perms *h,
+int checkpoint_fill_ipc_perms(struct ckpt_ctx *ctx,
+ struct ckpt_hdr_ipc_perms *h,
struct kern_ipc_perm *perm)
{
if (ipcperms(perm, S_IROTH))
@@ -45,6 +46,15 @@ int checkpoint_fill_ipc_perms(struct ckpt_hdr_ipc_perms *h,
h->cgid = perm->cgid;
h->mode = perm->mode & S_IRWXUGO;
h->seq = perm->seq;
+ if (perm->security) {
+ h->sec_ref = security_checkpoint_obj(ctx, perm->security,
+ CKPT_SECURITY_IPC);
+ if (h->sec_ref == -EOPNOTSUPP)
+ h->sec_ref = -1;
+ else if (h->sec_ref < 0)
+ return h->sec_ref;
+ } else
+ h->sec_ref = -1;
return 0;
}
@@ -176,7 +186,8 @@ static int validate_created_perms(struct ckpt_hdr_ipc_perms *h)
return 1;
}
-int restore_load_ipc_perms(struct ckpt_hdr_ipc_perms *h,
+int restore_load_ipc_perms(struct ckpt_ctx *ctx,
+ struct ckpt_hdr_ipc_perms *h,
struct kern_ipc_perm *perm)
{
if (h->id < 0)
@@ -205,14 +216,17 @@ int restore_load_ipc_perms(struct ckpt_hdr_ipc_perms *h,
perm->cgid = h->cgid;
perm->mode = h->mode;
perm->seq = h->seq;
- /*
- * Todo: restore perm->security.
- * At the moment it gets set by security_x_alloc() called through
- * ipcget()->ipcget_public()->ops-.getnew (->nequeue for instance)
- * We will want to ask the LSM to consider resetting the
- * checkpointed ->security, based on current_security(),
- * the checkpointed ->security, and the checkpoint file context.
- */
+
+ if ((ctx->uflags & RESTART_KEEP_LSM) && (h->sec_ref != -1)) {
+ int ret;
+ struct ckpt_stored_lsm *l = ckpt_obj_fetch(ctx, h->sec_ref,
+ CKPT_OBJ_SEC);
+ if (IS_ERR(l))
+ return PTR_ERR(l);
+ ret = security_ipc_restore(perm, l->string);
+ if (ret)
+ return ret;
+ }
return 0;
}
diff --git a/ipc/checkpoint_msg.c b/ipc/checkpoint_msg.c
index b933c19..24f4097 100644
--- a/ipc/checkpoint_msg.c
+++ b/ipc/checkpoint_msg.c
@@ -37,7 +37,7 @@ static int fill_ipc_msg_hdr(struct ckpt_ctx *ctx,
ipc_lock_by_ptr(&msq->q_perm);
- ret = checkpoint_fill_ipc_perms(&h->perms, &msq->q_perm);
+ ret = checkpoint_fill_ipc_perms(ctx, &h->perms, &msq->q_perm);
if (ret < 0)
goto unlock;
@@ -64,13 +64,23 @@ static int checkpoint_msg_contents(struct ckpt_ctx *ctx, struct msg_msg *msg)
struct msg_msgseg *seg;
int total, len;
int ret;
-
+ int sec_ref = -1;
+
+ if (msg->security) {
+ sec_ref = security_checkpoint_obj(ctx, msg->security,
+ CKPT_SECURITY_MSG_MSG);
+ if (sec_ref == -EOPNOTSUPP)
+ sec_ref = -1;
+ else if (sec_ref < 0)
+ return sec_ref;
+ }
h = ckpt_hdr_get_type(ctx, sizeof(*h), CKPT_HDR_IPC_MSG_MSG);
if (!h)
return -ENOMEM;
h->m_type = msg->m_type;
h->m_ts = msg->m_ts;
+ h->sec_ref = sec_ref;
ret = ckpt_write_obj(ctx, &h->h);
ckpt_hdr_put(ctx, h);
@@ -177,7 +187,7 @@ static int load_ipc_msg_hdr(struct ckpt_ctx *ctx,
{
int ret = 0;
- ret = restore_load_ipc_perms(&h->perms, &msq->q_perm);
+ ret = restore_load_ipc_perms(ctx, &h->perms, &msq->q_perm);
if (ret < 0)
return ret;
@@ -224,6 +234,16 @@ static struct msg_msg *restore_msg_contents_one(struct ckpt_ctx *ctx, int *clen)
msg->next = NULL;
pseg = &msg->next;
+ if ((ctx->uflags & RESTART_KEEP_LSM) && (h->sec_ref != -1)) {
+ struct ckpt_stored_lsm *l = ckpt_obj_fetch(ctx, h->sec_ref,
+ CKPT_OBJ_SEC);
+ if (IS_ERR(l))
+ return (struct msg_msg *)l;
+ ret = security_msg_msg_restore(msg, l->string);
+ if (ret)
+ return ERR_PTR(ret);
+ }
+
ret = _ckpt_read_buffer(ctx, (msg + 1), len);
if (ret < 0)
goto out;
diff --git a/ipc/checkpoint_sem.c b/ipc/checkpoint_sem.c
index 76eb2b9..53a19ed 100644
--- a/ipc/checkpoint_sem.c
+++ b/ipc/checkpoint_sem.c
@@ -37,7 +37,7 @@ static int fill_ipc_sem_hdr(struct ckpt_ctx *ctx,
ipc_lock_by_ptr(&sem->sem_perm);
- ret = checkpoint_fill_ipc_perms(&h->perms, &sem->sem_perm);
+ ret = checkpoint_fill_ipc_perms(ctx, &h->perms, &sem->sem_perm);
if (ret < 0)
goto unlock;
@@ -113,7 +113,7 @@ static int load_ipc_sem_hdr(struct ckpt_ctx *ctx,
{
int ret = 0;
- ret = restore_load_ipc_perms(&h->perms, &sem->sem_perm);
+ ret = restore_load_ipc_perms(ctx, &h->perms, &sem->sem_perm);
if (ret < 0)
return ret;
diff --git a/ipc/checkpoint_shm.c b/ipc/checkpoint_shm.c
index 826e430..01091d9 100644
--- a/ipc/checkpoint_shm.c
+++ b/ipc/checkpoint_shm.c
@@ -41,7 +41,7 @@ static int fill_ipc_shm_hdr(struct ckpt_ctx *ctx,
ipc_lock_by_ptr(&shp->shm_perm);
- ret = checkpoint_fill_ipc_perms(&h->perms, &shp->shm_perm);
+ ret = checkpoint_fill_ipc_perms(ctx, &h->perms, &shp->shm_perm);
if (ret < 0)
goto unlock;
@@ -165,7 +165,7 @@ static int load_ipc_shm_hdr(struct ckpt_ctx *ctx,
{
int ret;
- ret = restore_load_ipc_perms(&h->perms, &shp->shm_perm);
+ ret = restore_load_ipc_perms(ctx, &h->perms, &shp->shm_perm);
if (ret < 0)
return ret;
diff --git a/ipc/util.h b/ipc/util.h
index ba080de..ce34de0 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -199,9 +199,11 @@ void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp);
#ifdef CONFIG_CHECKPOINT
-extern int checkpoint_fill_ipc_perms(struct ckpt_hdr_ipc_perms *h,
+extern int checkpoint_fill_ipc_perms(struct ckpt_ctx *ctx,
+ struct ckpt_hdr_ipc_perms *h,
struct kern_ipc_perm *perm);
-extern int restore_load_ipc_perms(struct ckpt_hdr_ipc_perms *h,
+extern int restore_load_ipc_perms(struct ckpt_ctx *ctx,
+ struct ckpt_hdr_ipc_perms *h,
struct kern_ipc_perm *perm);
extern int ckpt_collect_ipc_shm(int id, void *p, void *data);
diff --git a/kernel/cred.c b/kernel/cred.c
index 9710cae..06bc676 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -709,7 +709,7 @@ int cred_setfsgid(struct cred *new, gid_t gid, gid_t *old_fsgid)
static int do_checkpoint_cred(struct ckpt_ctx *ctx, struct cred *cred)
{
int ret;
- int groupinfo_ref, user_ref;
+ int groupinfo_ref, user_ref, sec_ref = -1;
struct ckpt_hdr_cred *h;
groupinfo_ref = checkpoint_obj(ctx, cred->group_info,
@@ -719,6 +719,14 @@ static int do_checkpoint_cred(struct ckpt_ctx *ctx, struct cred *cred)
user_ref = checkpoint_obj(ctx, cred->user, CKPT_OBJ_USER);
if (user_ref < 0)
return user_ref;
+#ifdef CONFIG_SECURITY
+ sec_ref = security_checkpoint_obj(ctx, cred->security,
+ CKPT_SECURITY_CRED);
+ if (sec_ref == -EOPNOTSUPP)
+ sec_ref = -1;
+ else if (sec_ref < 0)
+ return sec_ref;
+#endif /* else cred->security doesn't exist and sec_ref = -1 */
h = ckpt_hdr_get_type(ctx, sizeof(*h), CKPT_HDR_CRED);
if (!h)
@@ -733,6 +741,7 @@ static int do_checkpoint_cred(struct ckpt_ctx *ctx, struct cred *cred)
h->sgid = cred->sgid;
h->egid = cred->egid;
h->fsgid = cred->fsgid;
+ h->sec_ref = sec_ref;
checkpoint_capabilities(&h->cap_s, cred);
@@ -806,6 +815,15 @@ static struct cred *do_restore_cred(struct ckpt_ctx *ctx)
ret = cred_setfsgid(cred, h->fsgid, &oldgid);
if (oldgid != h->fsgid && ret < 0)
goto err_putcred;
+ if ((ctx->uflags & RESTART_KEEP_LSM) && (h->sec_ref != -1)) {
+ struct ckpt_stored_lsm *l = ckpt_obj_fetch(ctx, h->sec_ref,
+ CKPT_OBJ_SEC);
+ if (IS_ERR(l))
+ return (struct cred *)l;
+ ret = security_cred_restore(ctx->file, cred, l->string);
+ if (ret)
+ goto err_putcred;
+ }
ret = restore_capabilities(&h->cap_s, cred);
if (ret)
goto err_putcred;
diff --git a/security/capability.c b/security/capability.c
index 88f752e..4e82df8 100644
--- a/security/capability.c
+++ b/security/capability.c
@@ -315,6 +315,16 @@ static int cap_file_permission(struct file *file, int mask)
return 0;
}
+static inline char *cap_file_checkpoint(void *security)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
+
+static int cap_file_restore(struct file *file, char *ctx)
+{
+ return -EOPNOTSUPP;
+}
+
static int cap_file_alloc_security(struct file *file)
{
return 0;
@@ -373,6 +383,16 @@ static int cap_task_create(unsigned long clone_flags)
return 0;
}
+static char *cap_cred_checkpoint(void *security)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
+
+static int cap_cred_restore(struct file *file, struct cred *cred, char *ctx)
+{
+ return -EOPNOTSUPP;
+}
+
static void cap_cred_free(struct cred *cred)
{
}
@@ -476,11 +496,31 @@ static void cap_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
*secid = 0;
}
+static char *cap_ipc_checkpoint(void *security)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
+
+static int cap_ipc_restore(struct kern_ipc_perm *ipcp, char *ctx)
+{
+ return -EOPNOTSUPP;
+}
+
static int cap_msg_msg_alloc_security(struct msg_msg *msg)
{
return 0;
}
+static inline char *cap_msg_msg_checkpoint(void *security)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
+
+static int cap_msg_msg_restore(struct msg_msg *msg, char *ctx)
+{
+ return -EOPNOTSUPP;
+}
+
static void cap_msg_msg_free_security(struct msg_msg *msg)
{
}
@@ -792,6 +832,28 @@ static void cap_release_secctx(char *secdata, u32 seclen)
{
}
+#ifdef CONFIG_CHECKPOINT
+void ckpt_snarf_lsm_info(struct ckpt_ctx *ctx);
+int ckpt_write_dummy_lsm_info(struct ckpt_ctx *ctx);
+static int cap_may_restart(struct ckpt_ctx *ctx)
+{
+ /*
+ * Note that all construction of kernel resources, credentials,
+ * etc is already authorized per the caller's credentials. This
+ * hook is intended for the LSM to make further decisions about
+ * a task not being allowed to restart at all, for instance if
+ * the policy has changed since checkpoint.
+ */
+ ckpt_snarf_lsm_info(ctx);
+ return 0;
+}
+
+static int cap_checkpoint_header(struct ckpt_ctx *ctx)
+{
+ return ckpt_write_dummy_lsm_info(ctx);
+}
+#endif
+
#ifdef CONFIG_KEYS
static int cap_key_alloc(struct key *key, const struct cred *cred,
unsigned long flags)
@@ -928,6 +990,8 @@ void security_fixup_ops(struct security_operations *ops)
set_to_cap_if_null(ops, path_truncate);
#endif
set_to_cap_if_null(ops, file_permission);
+ set_to_cap_if_null(ops, file_checkpoint);
+ set_to_cap_if_null(ops, file_restore);
set_to_cap_if_null(ops, file_alloc_security);
set_to_cap_if_null(ops, file_free_security);
set_to_cap_if_null(ops, file_ioctl);
@@ -940,6 +1004,8 @@ void security_fixup_ops(struct security_operations *ops)
set_to_cap_if_null(ops, file_receive);
set_to_cap_if_null(ops, dentry_open);
set_to_cap_if_null(ops, task_create);
+ set_to_cap_if_null(ops, cred_checkpoint);
+ set_to_cap_if_null(ops, cred_restore);
set_to_cap_if_null(ops, cred_free);
set_to_cap_if_null(ops, cred_prepare);
set_to_cap_if_null(ops, cred_commit);
@@ -966,7 +1032,11 @@ void security_fixup_ops(struct security_operations *ops)
set_to_cap_if_null(ops, task_to_inode);
set_to_cap_if_null(ops, ipc_permission);
set_to_cap_if_null(ops, ipc_getsecid);
+ set_to_cap_if_null(ops, ipc_checkpoint);
+ set_to_cap_if_null(ops, ipc_restore);
set_to_cap_if_null(ops, msg_msg_alloc_security);
+ set_to_cap_if_null(ops, msg_msg_checkpoint);
+ set_to_cap_if_null(ops, msg_msg_restore);
set_to_cap_if_null(ops, msg_msg_free_security);
set_to_cap_if_null(ops, msg_queue_alloc_security);
set_to_cap_if_null(ops, msg_queue_free_security);
@@ -992,6 +1062,10 @@ void security_fixup_ops(struct security_operations *ops)
set_to_cap_if_null(ops, secid_to_secctx);
set_to_cap_if_null(ops, secctx_to_secid);
set_to_cap_if_null(ops, release_secctx);
+#ifdef CONFIG_CHECKPOINT
+ set_to_cap_if_null(ops, may_restart);
+ set_to_cap_if_null(ops, checkpoint_header);
+#endif
#ifdef CONFIG_SECURITY_NETWORK
set_to_cap_if_null(ops, unix_stream_connect);
set_to_cap_if_null(ops, unix_may_send);
diff --git a/security/security.c b/security/security.c
index dc7674f..52647e0 100644
--- a/security/security.c
+++ b/security/security.c
@@ -122,6 +122,11 @@ int register_security(struct security_operations *ops)
return 0;
}
+char *security_get_lsm_name(void)
+{
+ return security_ops->name;
+}
+
/* Security operations */
int security_ptrace_may_access(struct task_struct *child, unsigned int mode)
@@ -625,6 +630,16 @@ int security_file_alloc(struct file *file)
return security_ops->file_alloc_security(file);
}
+char *security_file_checkpoint(void *security)
+{
+ return security_ops->file_checkpoint(security);
+}
+
+int security_file_restore(struct file *file, char *ctx)
+{
+ return security_ops->file_restore(file, ctx);
+}
+
void security_file_free(struct file *file)
{
security_ops->file_free_security(file);
@@ -684,6 +699,16 @@ int security_task_create(unsigned long clone_flags)
return security_ops->task_create(clone_flags);
}
+char *security_cred_checkpoint(void *security)
+{
+ return security_ops->cred_checkpoint(security);
+}
+
+int security_cred_restore(struct file *file, struct cred *cred, char *ctx)
+{
+ return security_ops->cred_restore(file, cred, ctx);
+}
+
void security_cred_free(struct cred *cred)
{
security_ops->cred_free(cred);
@@ -819,11 +844,31 @@ void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
security_ops->ipc_getsecid(ipcp, secid);
}
+char *security_ipc_checkpoint(void *security)
+{
+ return security_ops->ipc_checkpoint(security);
+}
+
+int security_ipc_restore(struct kern_ipc_perm *ipcp, char *ctx)
+{
+ return security_ops->ipc_restore(ipcp, ctx);
+}
+
int security_msg_msg_alloc(struct msg_msg *msg)
{
return security_ops->msg_msg_alloc_security(msg);
}
+char *security_msg_msg_checkpoint(void *security)
+{
+ return security_ops->msg_msg_checkpoint(security);
+}
+
+int security_msg_msg_restore(struct msg_msg *msg, char *ctx)
+{
+ return security_ops->msg_msg_restore(msg, ctx);
+}
+
void security_msg_msg_free(struct msg_msg *msg)
{
security_ops->msg_msg_free_security(msg);
@@ -959,6 +1004,20 @@ void security_release_secctx(char *secdata, u32 seclen)
}
EXPORT_SYMBOL(security_release_secctx);
+#ifdef CONFIG_CHECKPOINT
+int security_may_restart(struct ckpt_ctx *ctx)
+{
+ return security_ops->may_restart(ctx);
+}
+EXPORT_SYMBOL(security_may_restart);
+
+int security_checkpoint_header(struct ckpt_ctx *ctx)
+{
+ return security_ops->checkpoint_header(ctx);
+}
+EXPORT_SYMBOL(security_checkpoint_header);
+#endif
+
#ifdef CONFIG_SECURITY_NETWORK
int security_unix_stream_connect(struct socket *sock, struct socket *other,
@@ -1244,3 +1303,75 @@ int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule,
}
#endif /* CONFIG_AUDIT */
+
+#ifdef CONFIG_CHECKPOINT
+
+#include <linux/checkpoint.h>
+
+/**
+ * security_checkpoint_obj - if first checkpoint of this void* security,
+ * then 1. ask the LSM for a string representing the context, 2. checkpoint
+ * that string
+ * @ctx: the checkpoint context
+ * @security: the void* security being checkpointed
+ * @sectype: indicates the type of object, because LSMs can (and do) store
+ * different types of data for different types of objects.
+ *
+ * Returns the objref of the checkpointed ckpt_stored_lsm representing the
+ * context, or -error on error.
+ *
+ * This is only used at checkpoint of course.
+ */
+int security_checkpoint_obj(struct ckpt_ctx *ctx, void *security,
+ unsigned sectype)
+{
+ int strref;
+ struct ckpt_stored_lsm *l;
+ char *str;
+ int len;
+
+ /*
+ * to simplify the LSM code, short-cut a null security
+ * here.
+ */
+ if (!security)
+ return -EOPNOTSUPP;
+
+ switch (sectype) {
+ case CKPT_SECURITY_MSG_MSG:
+ str = security_msg_msg_checkpoint(security);
+ break;
+ case CKPT_SECURITY_IPC:
+ str = security_ipc_checkpoint(security);
+ break;
+ case CKPT_SECURITY_FILE:
+ str = security_file_checkpoint(security);
+ break;
+ case CKPT_SECURITY_CRED:
+ str = security_cred_checkpoint(security);
+ break;
+ default:
+ str = ERR_PTR(-EINVAL);
+ break;
+ }
+ /* str will be alloc'ed for us by the LSM. We will free it when
+ * we clear out our hashtable */
+ if (IS_ERR(str))
+ return PTR_ERR(str);
+
+ len = strlen(str);
+ l = kzalloc(sizeof(*l) + len + 1, GFP_KERNEL);
+ if (!l) {
+ kfree(str);
+ return -ENOMEM;
+ }
+ kref_init(&l->kref);
+ l->sectype = sectype;
+ l->string = str;
+
+ strref = checkpoint_obj(ctx, l, CKPT_OBJ_SEC);
+ /* do we need to free l if strref was err? */
+ return strref;
+}
+
+#endif
--
1.6.1
^ permalink raw reply related [flat|nested] 22+ messages in thread
* [PATCH 1/3] cr: add generic LSM c/r support (v4)
@ 2009-10-02 3:49 ` Serge E. Hallyn
0 siblings, 0 replies; 22+ messages in thread
From: Serge E. Hallyn @ 2009-10-02 3:49 UTC (permalink / raw)
To: Linux Containers
Cc: linux-security-module, SELinux, Casey Schaufler, Stephen Smalley
(wasn't versioning the patchsets before, so randomly pick 4 as
the version for this patchset...)
Documentation/checkpoint/readme.txt begins:
"""
Application checkpoint/restart is the ability to save the state
of a running application so that it can later resume its execution
from the time at which it was checkpointed.
"""
This patch adds generic support for c/r of LSM credentials. Support
for Smack and SELinux (and TOMOYO if appropriate) will be added later.
Capabilities is already supported through generic creds code.
This patch supports ipc_perm, msg_msg, cred (task) and file ->security
fields. Inodes, superblocks, netif, and xfrm currently are restored
not through sys_restart() but through container creation, and so the
security fields should be done then as well. Network should be added
when network c/r is added.
Briefly, all security fields must be exported by the LSM as a simple
null-terminated string. They are checkpointed through the
security_checkpoint_obj() helper, because we must pass it an extra
sectype field. Splitting SECURITY_OBJ_SEC into one type per object
type would not work because, in Smack, one void* security is used for
all object types. But we must pass the sectype field because in
SELinux a different type of structure is stashed in each object type.
The RESTART_KEEP_LSM flag indicates that the LSM should
attempt to reuse checkpointed security labels. It is always
invalid when the LSM at restart differs from that at checkpoint.
It is currently only usable for capabilities.
(For capabilities, restart without RESTART_KEEP_LSM is technically
not implemented. There actually might be a use case for that,
but the safety of it is dubious so for now we always re-create
checkpointed capability sets whether RESTART_KEEP_LSM is
specified or not)
The result of applying this patchset can be seen at
http://git.kernel.org/gitweb.cgi?p=linux/kernel/git/sergeh/linux-cr.git;a=shortlog;h=ckpt-v18-hallyn.lsm3
Changelog:
sep 3: fix memory leak on LSM restore error path
Sep 3: provide 2 hooks, may_restart and checkpoint_header, to facilitate
an LSM tracking policy changes.
sep 10: merge RESTART_KEEP_LSM patch with basic LSM c/r
support patches.
sep 10: rename security_xyz_get_ctx() to security_xyz_checkpoint(),
in order to avoid confusing with the various other 'context'
helpers in the security_ namespace, relating to secids and
sysfs xattrs.
sep 10: pass context file to security_cred_restore. SELinux will
want the file's security context to authorize it as an
entrypoint for the new process context.
oct 01: roll up some generic c/r debug hunks from selinux patch.
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Stephen Smalley <sds@epoch.ncsc.mil>
Cc: Casey Schaufler <casey@schaufler-ca.com>
---
Documentation/checkpoint/readme.txt | 25 +++++
checkpoint/checkpoint.c | 11 ++
checkpoint/files.c | 34 +++++++
checkpoint/objhash.c | 93 +++++++++++++++++
checkpoint/process.c | 20 +++-
checkpoint/restart.c | 25 +++++
checkpoint/sys.c | 22 ++++
include/linux/checkpoint.h | 7 +-
include/linux/checkpoint_hdr.h | 24 +++++-
include/linux/checkpoint_types.h | 9 ++
include/linux/security.h | 188 +++++++++++++++++++++++++++++++++++
ipc/checkpoint.c | 34 +++++--
ipc/checkpoint_msg.c | 26 +++++-
ipc/checkpoint_sem.c | 4 +-
ipc/checkpoint_shm.c | 4 +-
ipc/util.h | 6 +-
kernel/cred.c | 20 ++++-
security/capability.c | 74 ++++++++++++++
security/security.c | 131 ++++++++++++++++++++++++
19 files changed, 731 insertions(+), 26 deletions(-)
diff --git a/Documentation/checkpoint/readme.txt b/Documentation/checkpoint/readme.txt
index 571c469..8ec5850 100644
--- a/Documentation/checkpoint/readme.txt
+++ b/Documentation/checkpoint/readme.txt
@@ -333,6 +333,31 @@ So that's why we don't want CAP_SYS_ADMIN required up-front. That way
we will be forced to more carefully review each of those features.
However, this can be controlled with a sysctl-variable.
+LSM
+===
+
+Security modules use custom labels on subjects and objects to
+further mediate access decisions beyond DAC controls. When
+checkpoint applications, these labels are [ work in progress ]
+checkpointed along with the objects. At restart, the
+RESTART_KEEP_LSM flag tells the kernel whether re-created objects
+whould keep their checkpointed labels, or get automatically
+recalculated labels. Since checkpointed labels will only make
+sense to the same LSM which was active at checkpoint time,
+sys_restart() with the RESTART_KEEP_LSM flag will fail with
+-EINVAL if the LSM active at restart is not the same as that
+active at checkpoint. If RESTART_KEEP_LSM is not specified,
+then objects will be given whatever default labels the LSM and
+their optional policy decide. Of course, when RESTART_KEEP_LSM
+is specified, the LSM may choose a different label than the
+checkpointed one, or fail the entire restart if the caller
+does not have permission to create objects with the checkpointed
+label.
+
+It should always be safe to take a checkpoint of an application
+under LSM_1, and restart it without the RESTART_KEEP_LSM flag
+under LSM_2.
+
Kernel interfaces
=================
diff --git a/checkpoint/checkpoint.c b/checkpoint/checkpoint.c
index 1eeb557..6722035 100644
--- a/checkpoint/checkpoint.c
+++ b/checkpoint/checkpoint.c
@@ -25,6 +25,7 @@
#include <linux/magic.h>
#include <linux/hrtimer.h>
#include <linux/deferqueue.h>
+#include <linux/security.h>
#include <linux/checkpoint.h>
#include <linux/checkpoint_hdr.h>
@@ -351,6 +352,16 @@ static int checkpoint_write_header(struct ckpt_ctx *ctx)
if (ret < 0)
return ret;
+ memset(ctx->lsm_name, 0, SECURITY_NAME_MAX + 1);
+ strlcpy(ctx->lsm_name, security_get_lsm_name(), SECURITY_NAME_MAX + 1);
+ ret = ckpt_write_buffer(ctx, ctx->lsm_name, SECURITY_NAME_MAX + 1);
+ if (ret < 0)
+ return ret;
+
+ ret = security_checkpoint_header(ctx);
+ if (ret < 0)
+ return ret;
+
return checkpoint_write_header_arch(ctx);
}
diff --git a/checkpoint/files.c b/checkpoint/files.c
index 27e29a0..570facb 100644
--- a/checkpoint/files.c
+++ b/checkpoint/files.c
@@ -145,6 +145,19 @@ static int scan_fds(struct files_struct *files, int **fdtable)
return n;
}
+#ifdef CONFIG_SECURITY
+int checkpoint_file_security(struct ckpt_ctx *ctx, struct file *file)
+{
+ return security_checkpoint_obj(ctx, file->f_security,
+ CKPT_SECURITY_FILE);
+}
+#else
+int checkpoint_file_security(struct ckpt_ctx *ctx, struct file *file)
+{
+ return -EOPNOTSUPP;
+}
+#endif
+
int checkpoint_file_common(struct ckpt_ctx *ctx, struct file *file,
struct ckpt_hdr_file *h)
{
@@ -159,6 +172,16 @@ int checkpoint_file_common(struct ckpt_ctx *ctx, struct file *file,
if (h->f_credref < 0)
return h->f_credref;
+ h->f_secref = checkpoint_file_security(ctx, file);
+ if (h->f_secref == -EOPNOTSUPP)
+ h->f_secref = -1;
+ else if (h->f_secref < 0)
+ return h->f_secref;
+
+ ckpt_debug("file %s credref %d secref %d",
+ file->f_dentry->d_name.name, h->f_credref,
+ h->f_secref);
+
/* FIX: need also file->f_owner, etc */
return 0;
@@ -507,6 +530,17 @@ int restore_file_common(struct ckpt_ctx *ctx, struct file *file,
put_cred(file->f_cred);
file->f_cred = get_cred(cred);
+ if ((ctx->uflags & RESTART_KEEP_LSM) && (h->f_secref != -1)) {
+ struct ckpt_stored_lsm *l = ckpt_obj_fetch(ctx, h->f_secref,
+ CKPT_OBJ_SEC);
+ if (IS_ERR(l))
+ return PTR_ERR(l);
+
+ ret = security_file_restore(file, l->string);
+ if (ret)
+ return ret;
+ }
+
/* safe to set 1st arg (fd) to 0, as command is F_SETFL */
ret = vfs_fcntl(0, F_SETFL, h->f_flags & CKPT_SETFL_MASK, file);
if (ret < 0)
diff --git a/checkpoint/objhash.c b/checkpoint/objhash.c
index f84388d..58ff040 100644
--- a/checkpoint/objhash.c
+++ b/checkpoint/objhash.c
@@ -16,6 +16,7 @@
#include <linux/file.h>
#include <linux/fdtable.h>
#include <linux/sched.h>
+#include <linux/kref.h>
#include <linux/ipc_namespace.h>
#include <linux/user_namespace.h>
#include <linux/checkpoint.h>
@@ -285,6 +286,89 @@ static int obj_tty_users(void *ptr)
return atomic_read(&((struct tty_struct *) ptr)->kref.refcount);
}
+static void obj_free_sec(struct kref *kref)
+{
+ struct ckpt_stored_lsm *s = container_of(kref, struct ckpt_stored_lsm,
+ kref);
+ kfree(s->string);
+ kfree(s);
+}
+
+static int obj_sec_grab(void *ptr)
+{
+ struct ckpt_stored_lsm *s = ptr;
+ kref_get(&s->kref);
+ return 0;
+}
+
+static void obj_sec_drop(void *ptr, int lastref)
+{
+ struct ckpt_stored_lsm *s = ptr;
+ kref_put(&s->kref, obj_free_sec);
+}
+
+static int do_checkpoint_security(struct ckpt_ctx *ctx,
+ const struct ckpt_stored_lsm *l)
+{
+ int ret, len;
+ struct ckpt_hdr_lsm *h;
+
+ len = strlen(l->string);
+ if (len > PAGE_SIZE - sizeof(*h))
+ return -E2BIG;
+ h = ckpt_hdr_get_type(ctx, sizeof(*h)+len+1, CKPT_HDR_SEC);
+ if (!h)
+ return -ENOMEM;
+ h->len = len;
+ h->sectype = l->sectype;
+ strncpy(h->string, l->string, len);
+ h->string[len] = '\0';
+ ret = ckpt_write_obj(ctx, &h->h);
+ ckpt_hdr_put(ctx, h);
+ return ret;
+}
+
+static int checkpoint_security(struct ckpt_ctx *ctx, void *ptr)
+{
+ return do_checkpoint_security(ctx, (struct ckpt_stored_lsm *) ptr);
+}
+
+static struct ckpt_stored_lsm *do_restore_security(struct ckpt_ctx *ctx)
+{
+ struct ckpt_hdr_lsm *h;
+ struct ckpt_stored_lsm *l;
+
+ h = ckpt_read_buf_type(ctx, PAGE_SIZE, CKPT_HDR_SEC);
+ if (IS_ERR(h))
+ return (struct ckpt_stored_lsm *)h;
+ if (h->len > h->h.len - sizeof(struct ckpt_hdr) ||
+ h->len > PAGE_SIZE) {
+ ckpt_hdr_put(ctx, h);
+ return ERR_PTR(-EINVAL);
+ }
+ l = kzalloc(sizeof(*l), GFP_KERNEL);
+ if (!l) {
+ ckpt_hdr_put(ctx, h);
+ return ERR_PTR(-ENOMEM);
+ }
+ l->string = kzalloc(h->len + 1, GFP_KERNEL);
+ if (!l->string) {
+ kfree(l);
+ ckpt_hdr_put(ctx, h);
+ return ERR_PTR(-ENOMEM);
+ }
+ kref_init(&l->kref);
+ l->sectype = h->sectype;
+ strncpy(l->string, h->string, h->len);
+ ckpt_hdr_put(ctx, h);
+ return l;
+}
+
+static void *restore_security(struct ckpt_ctx *ctx)
+{
+ return (void *) do_restore_security(ctx);
+}
+
static struct ckpt_obj_ops ckpt_obj_ops[] = {
/* ignored object */
{
@@ -433,6 +517,15 @@ static struct ckpt_obj_ops ckpt_obj_ops[] = {
.checkpoint = checkpoint_tty,
.restore = restore_tty,
},
+ /* LSM security labels */
+ {
+ .obj_name = "LSM",
+ .obj_type = CKPT_OBJ_SEC,
+ .ref_drop = obj_sec_drop,
+ .ref_grab = obj_sec_grab,
+ .checkpoint = checkpoint_security,
+ .restore = restore_security,
+ },
};
diff --git a/checkpoint/process.c b/checkpoint/process.c
index 5ba64f0..ed7896c 100644
--- a/checkpoint/process.c
+++ b/checkpoint/process.c
@@ -581,11 +581,15 @@ static int restore_task_creds(struct ckpt_ctx *ctx)
realcred = ckpt_obj_fetch(ctx, h->cred_ref, CKPT_OBJ_CRED);
if (IS_ERR(realcred)) {
+ ckpt_debug("Error %ld fetching readlcred (ref %d)",
+ PTR_ERR(realcred), h->cred_ref);
ret = PTR_ERR(realcred);
goto out;
}
ecred = ckpt_obj_fetch(ctx, h->ecred_ref, CKPT_OBJ_CRED);
if (IS_ERR(ecred)) {
+ ckpt_debug("Error %ld fetching ecred (ref %d)",
+ PTR_ERR(ecred), h->ecred_ref);
ret = PTR_ERR(ecred);
goto out;
}
@@ -593,6 +597,7 @@ static int restore_task_creds(struct ckpt_ctx *ctx)
ctx->ecred = ecred;
out:
+ ckpt_debug("Returning %d.", ret);
ckpt_hdr_put(ctx, h);
return ret;
}
@@ -608,14 +613,21 @@ static int restore_task_objs(struct ckpt_ctx *ctx)
* referenced. See comment in checkpoint_task_objs.
*/
ret = restore_task_creds(ctx);
- if (!ret)
- ret = restore_task_ns(ctx);
- if (ret < 0)
+ if (ret) {
+ ckpt_debug("restore_task_creds returned %d", ret);
+ return ret;
+ }
+ ret = restore_task_ns(ctx);
+ if (ret) {
+ ckpt_debug("restore_task_ns returned %d", ret);
return ret;
+ }
h = ckpt_read_obj_type(ctx, sizeof(*h), CKPT_HDR_TASK_OBJS);
- if (IS_ERR(h))
+ if (IS_ERR(h)) {
+ ckpt_debug("Error fetching task obj");
return PTR_ERR(h);
+ }
ret = restore_obj_file_table(ctx, h->files_objref);
ckpt_debug("file_table: ret %d (%p)\n", ret, current->files);
diff --git a/checkpoint/restart.c b/checkpoint/restart.c
index b12c8bd..bba2b45 100644
--- a/checkpoint/restart.c
+++ b/checkpoint/restart.c
@@ -457,6 +457,31 @@ static int restore_read_header(struct ckpt_ctx *ctx)
if (ret < 0)
goto out;
+ ret = _ckpt_read_buffer(ctx, ctx->lsm_name, SECURITY_NAME_MAX + 1);
+ if (ret < 0)
+ goto out;
+ if (ctx->uflags & RESTART_KEEP_LSM) {
+ char *cur = security_get_lsm_name();
+ if (strncmp(cur, ctx->lsm_name, SECURITY_NAME_MAX + 1) != 0) {
+ pr_warning("c/r: checkpointed LSM %s, current is %s.\n",
+ ctx->lsm_name, cur);
+ ret = -EINVAL;
+ goto out;
+ }
+ /* to be implemented later, per-lsm */
+ if (strcmp(ctx->lsm_name, "lsm_none") != 0 &&
+ strcmp(ctx->lsm_name, "default") != 0) {
+ pr_warning("c/r: RESTART_KEEP_LSM unsupported for %s\n",
+ ctx->lsm_name);
+ ret = -ENOSYS;
+ goto out;
+ }
+ }
+
+ ret = security_may_restart(ctx);
+ if (ret < 0)
+ goto out;
+
ret = restore_read_header_arch(ctx);
out:
kfree(uts);
diff --git a/checkpoint/sys.c b/checkpoint/sys.c
index 7604089..0a1e8a6 100644
--- a/checkpoint/sys.c
+++ b/checkpoint/sys.c
@@ -169,6 +169,28 @@ void *ckpt_hdr_get_type(struct ckpt_ctx *ctx, int len, int type)
return h;
}
+#define DUMMY_LSM_INFO "dummy"
+
+int ckpt_write_dummy_lsm_info(struct ckpt_ctx *ctx)
+{
+ return ckpt_write_obj_type(ctx, DUMMY_LSM_INFO,
+ strlen(DUMMY_LSM_INFO), CKPT_HDR_LSM_INFO);
+}
+
+/*
+ * ckpt_snarf_lsm_info
+ * If there is a CKPT_HDR_LSM_INFO field, toss it.
+ * Used when the current LSM doesn't care about this field.
+ */
+void ckpt_snarf_lsm_info(struct ckpt_ctx *ctx)
+{
+ struct ckpt_hdr *h;
+
+ h = ckpt_read_buf_type(ctx, CKPT_LSM_INFO_LEN, CKPT_HDR_LSM_INFO);
+ if (!IS_ERR(h))
+ ckpt_hdr_put(ctx, h);
+}
+
/*
* Helpers to manage c/r contexts: allocated for each checkpoint and/or
diff --git a/include/linux/checkpoint.h b/include/linux/checkpoint.h
index e403dd7..707f9fb 100644
--- a/include/linux/checkpoint.h
+++ b/include/linux/checkpoint.h
@@ -10,7 +10,7 @@
* distribution for more details.
*/
-#define CHECKPOINT_VERSION 2
+#define CHECKPOINT_VERSION 3
/* checkpoint user flags */
#define CHECKPOINT_SUBTREE 0x1
@@ -19,6 +19,7 @@
#define RESTART_TASKSELF 0x1
#define RESTART_FROZEN 0x2
#define RESTART_GHOST 0x4
+#define RESTART_KEEP_LSM 0x8
#ifdef __KERNEL__
#ifdef CONFIG_CHECKPOINT
@@ -48,7 +49,9 @@
#define RESTART_USER_FLAGS \
(RESTART_TASKSELF | \
RESTART_FROZEN | \
+ RESTART_KEEP_LSM | \
RESTART_GHOST)
+#define CKPT_LSM_INFO_LEN 200
extern int walk_task_subtree(struct task_struct *task,
int (*func)(struct task_struct *, void *),
@@ -62,6 +65,8 @@ extern void _ckpt_hdr_put(struct ckpt_ctx *ctx, void *ptr, int n);
extern void ckpt_hdr_put(struct ckpt_ctx *ctx, void *ptr);
extern void *ckpt_hdr_get(struct ckpt_ctx *ctx, int n);
extern void *ckpt_hdr_get_type(struct ckpt_ctx *ctx, int n, int type);
+extern int ckpt_write_dummy_lsm_info(struct ckpt_ctx *ctx);
+extern void ckpt_snarf_lsm_info(struct ckpt_ctx *ctx);
extern int ckpt_write_obj(struct ckpt_ctx *ctx, struct ckpt_hdr *h);
extern int ckpt_write_obj_type(struct ckpt_ctx *ctx,
diff --git a/include/linux/checkpoint_hdr.h b/include/linux/checkpoint_hdr.h
index 2ed523f..61ac537 100644
--- a/include/linux/checkpoint_hdr.h
+++ b/include/linux/checkpoint_hdr.h
@@ -58,6 +58,8 @@ enum {
CKPT_HDR_BUFFER,
CKPT_HDR_STRING,
CKPT_HDR_OBJREF,
+ CKPT_HDR_SEC,
+ CKPT_HDR_LSM_INFO,
CKPT_HDR_TREE = 101,
CKPT_HDR_TASK,
@@ -146,6 +148,7 @@ enum obj_type {
CKPT_OBJ_GROUPINFO,
CKPT_OBJ_SOCK,
CKPT_OBJ_TTY,
+ CKPT_OBJ_SEC,
CKPT_OBJ_MAX
};
@@ -189,10 +192,11 @@ struct ckpt_hdr_header {
__u64 uflags; /* uflags from checkpoint */
/*
- * the header is followed by three strings:
+ * the header is followed by four strings:
* char release[const.uts_release_len];
* char version[const.uts_version_len];
* char machine[const.uts_machine_len];
+ * char lsm_name[SECURITY_NAME_MAX + 1]
*/
} __attribute__((aligned(8)));
@@ -265,6 +269,8 @@ struct ckpt_hdr_cred {
__u32 gid, sgid, egid, fsgid;
__s32 user_ref;
__s32 groupinfo_ref;
+ __s32 sec_ref;
+ __u32 padding;
struct ckpt_capabilities cap_s;
} __attribute__((aligned(8)));
@@ -277,6 +283,16 @@ struct ckpt_hdr_groupinfo {
__u32 groups[0];
} __attribute__((aligned(8)));
+struct ckpt_hdr_lsm {
+ struct ckpt_hdr h;
+ __u8 sectype;
+ __u16 len;
+ /*
+ * This is followed by a string of size len+1,
+ * null-terminated
+ */
+ __u8 string[0];
+} __attribute__((aligned(8)));
/*
* todo - keyrings and LSM
* These may be better done with userspace help though
@@ -392,6 +408,8 @@ struct ckpt_hdr_file {
__s32 f_credref;
__u64 f_pos;
__u64 f_version;
+ __s32 f_secref;
+ __u32 f_padding;
} __attribute__((aligned(8)));
struct ckpt_hdr_file_generic {
@@ -634,6 +652,8 @@ struct ckpt_hdr_ipc_perms {
__u32 mode;
__u32 _padding;
__u64 seq;
+ __s32 sec_ref;
+ __u32 padding;
} __attribute__((aligned(8)));
struct ckpt_hdr_ipc_shm {
@@ -667,6 +687,8 @@ struct ckpt_hdr_ipc_msg_msg {
struct ckpt_hdr h;
__s32 m_type;
__u32 m_ts;
+ __s32 sec_ref;
+ __u32 padding;
} __attribute__((aligned(8)));
struct ckpt_hdr_ipc_sem {
diff --git a/include/linux/checkpoint_types.h b/include/linux/checkpoint_types.h
index b9393f4..6a2c9dc 100644
--- a/include/linux/checkpoint_types.h
+++ b/include/linux/checkpoint_types.h
@@ -21,6 +21,7 @@
#include <linux/fs.h>
#include <linux/ktime.h>
#include <linux/wait.h>
+#include <linux/security.h>
struct ckpt_stats {
int uts_ns;
@@ -42,6 +43,7 @@ struct ckpt_ctx {
struct task_struct *root_task; /* [container] root task */
struct nsproxy *root_nsproxy; /* [container] root nsproxy */
struct task_struct *root_freezer; /* [container] root task */
+ char lsm_name[SECURITY_NAME_MAX + 1]; /* security module at ckpt */
unsigned long kflags; /* kerenl flags */
unsigned long uflags; /* user flags */
@@ -82,6 +84,13 @@ struct ckpt_ctx {
struct ckpt_stats stats; /* statistics */
};
+/* stored on hashtable */
+struct ckpt_stored_lsm {
+ struct kref kref;
+ int sectype;
+ char *string;
+};
+
#endif /* __KERNEL__ */
#endif /* _LINUX_CHECKPOINT_TYPES_H_ */
diff --git a/include/linux/security.h b/include/linux/security.h
index 1f16eea..67f9c53 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -46,6 +46,10 @@
struct ctl_table;
struct audit_krule;
+#ifdef CONFIG_CHECKPOINT
+struct ckpt_ctx;
+#endif
+
/*
* These functions are in security/capability.c and are used
* as the default capabilities functions
@@ -574,6 +578,15 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
* created.
* @file contains the file structure to secure.
* Return 0 if the hook is successful and permission is granted.
+ * @file_checkpoint:
+ * Return a string representing the security context on a file.
+ * @security contains the security field.
+ * Returns a char* which the caller will free, or -error on error.
+ * @file_restore:
+ * Set a security context on a file according to the checkpointed context.
+ * @file contains the file.
+ * @ctx contains a string representation of the checkpointed context.
+ * Returns 0 on success, -error on failure.
* @file_free_security:
* Deallocate and free any security structures stored in file->f_security.
* @file contains the file structure being modified.
@@ -653,6 +666,17 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
* manual page for definitions of the @clone_flags.
* @clone_flags contains the flags indicating what should be shared.
* Return 0 if permission is granted.
+ * @cred_checkpoint:
+ * Return a string representing the security context on the task cred.
+ * @security contains the security field.
+ * Returns a char* which the caller will free, or -error on error.
+ * @cred_restore:
+ * Set a security context on a task cred according to the checkpointed
+ * context.
+ * @file contains the checkpoint file
+ * @cred contains the cred.
+ * @ctx contains a string representation of the checkpointed context.
+ * Returns 0 on success, -error on failure.
* @cred_free:
* @cred points to the credentials.
* Deallocate and clear the cred->security field in a set of credentials.
@@ -1101,6 +1125,19 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
* @ipcp contains the kernel IPC permission structure.
* @secid contains a pointer to the location where result will be saved.
* In case of failure, @secid will be set to zero.
+ * @ipc_checkpoint:
+ * Return a string representing the security context on the IPC
+ * permission structure.
+ * @security contains the security field.
+ * Returns a char* which the caller will free, or -error on error.
+ * @ipc_restore:
+ * Set a security context on a IPC permission structure according to
+ * the checkpointed context.
+ * @ipcp contains the IPC permission structure, which will have
+ * already been allocated and initialized when the IPC structure was
+ * created.
+ * @ctx contains a string representation of the checkpointed context.
+ * Returns 0 on success, -error on failure.
*
* Security hooks for individual messages held in System V IPC message queues
* @msg_msg_alloc_security:
@@ -1109,6 +1146,16 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
* created.
* @msg contains the message structure to be modified.
* Return 0 if operation was successful and permission is granted.
+ * @msg_msg_checkpoint:
+ * Return a string representing the security context on an msg_msg
+ * struct.
+ * @security contains the security field
+ * Returns a char* which the caller will free, or -error on error.
+ * @msg_msg_restore:
+ * Set msg_msg->security according to the checkpointed context.
+ * @msg contains the message structure to be modified.
+ * @ctx contains a string representation of the checkpointed context.
+ * Return 0 on success, -error on failure.
* @msg_msg_free_security:
* Deallocate the security structure for this message.
* @msg contains the message structure to be modified.
@@ -1320,6 +1367,28 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
* @secdata contains the security context.
* @seclen contains the length of the security context.
*
+ * Security hooks for Checkpoint/restart
+ * (In addition to *_checkpoint and *_restore)
+ *
+ * @may_restart:
+ * Authorize sys_restart().
+ * Note that all construction of kernel resources, credentials,
+ * etc is already authorized per the caller's credentials. This
+ * hook is intended for the LSM to make further decisions about
+ * a task not being allowed to restart at all, for instance if
+ * the policy has changed since checkpoint.
+ * @ctx is the checkpoint/restart context (see <linux/checkpoint_types.h>)
+ * Return 0 if allowed, <0 on error.
+ *
+ * @checkpoint_header:
+ * Optionally write out a LSM-specific checkpoint header. This is
+ * a chance to write out policy information, for instance. The same
+ * LSM on restart can then use the info in security_may_restart() to
+ * refuse restart (for instance) across policy changes.
+ * The info is to be written as a an object of type CKPT_HDR_LSM_INFO.
+ * @ctx is the checkpoint/restart context (see <linux/checkpoint_types.h>)
+ * Return 0 on success, <0 on error.
+ *
* Security hooks for Audit
*
* @audit_rule_init:
@@ -1463,6 +1532,8 @@ struct security_operations {
int (*file_permission) (struct file *file, int mask);
int (*file_alloc_security) (struct file *file);
+ char *(*file_checkpoint) (void *security);
+ int (*file_restore) (struct file *file, char *ctx);
void (*file_free_security) (struct file *file);
int (*file_ioctl) (struct file *file, unsigned int cmd,
unsigned long arg);
@@ -1483,6 +1554,8 @@ struct security_operations {
int (*dentry_open) (struct file *file, const struct cred *cred);
int (*task_create) (unsigned long clone_flags);
+ char *(*cred_checkpoint) (void *security);
+ int (*cred_restore) (struct file *file, struct cred *cred, char *ctx);
void (*cred_free) (struct cred *cred);
int (*cred_prepare)(struct cred *new, const struct cred *old,
gfp_t gfp);
@@ -1516,8 +1589,12 @@ struct security_operations {
int (*ipc_permission) (struct kern_ipc_perm *ipcp, short flag);
void (*ipc_getsecid) (struct kern_ipc_perm *ipcp, u32 *secid);
+ char *(*ipc_checkpoint) (void *security);
+ int (*ipc_restore) (struct kern_ipc_perm *ipcp, char *ctx);
int (*msg_msg_alloc_security) (struct msg_msg *msg);
+ char *(*msg_msg_checkpoint) (void *security);
+ int (*msg_msg_restore) (struct msg_msg *msg, char *ctx);
void (*msg_msg_free_security) (struct msg_msg *msg);
int (*msg_queue_alloc_security) (struct msg_queue *msq);
@@ -1556,6 +1633,11 @@ struct security_operations {
int (*secctx_to_secid) (const char *secdata, u32 seclen, u32 *secid);
void (*release_secctx) (char *secdata, u32 seclen);
+#ifdef CONFIG_CHECKPOINT
+ int (*may_restart) (struct ckpt_ctx *ctx);
+ int (*checkpoint_header) (struct ckpt_ctx *ctx);
+#endif
+
#ifdef CONFIG_SECURITY_NETWORK
int (*unix_stream_connect) (struct socket *sock,
struct socket *other, struct sock *newsk);
@@ -1721,6 +1803,8 @@ int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer
void security_inode_getsecid(const struct inode *inode, u32 *secid);
int security_file_permission(struct file *file, int mask);
int security_file_alloc(struct file *file);
+char *security_file_checkpoint(void *security);
+int security_file_restore(struct file *file, char *ctx);
void security_file_free(struct file *file);
int security_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
int security_file_mmap(struct file *file, unsigned long reqprot,
@@ -1736,6 +1820,8 @@ int security_file_send_sigiotask(struct task_struct *tsk,
int security_file_receive(struct file *file);
int security_dentry_open(struct file *file, const struct cred *cred);
int security_task_create(unsigned long clone_flags);
+char *security_cred_checkpoint(void *security);
+int security_cred_restore(struct file *file, struct cred *cred, char *ctx);
void security_cred_free(struct cred *cred);
int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp);
void security_commit_creds(struct cred *new, const struct cred *old);
@@ -1766,7 +1852,11 @@ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3,
void security_task_to_inode(struct task_struct *p, struct inode *inode);
int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag);
void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid);
+char *security_ipc_checkpoint(void *security);
+int security_ipc_restore(struct kern_ipc_perm *ipcp, char *ctx);
int security_msg_msg_alloc(struct msg_msg *msg);
+char *security_msg_msg_checkpoint(void *security);
+int security_msg_msg_restore(struct msg_msg *msg, char *ctx);
void security_msg_msg_free(struct msg_msg *msg);
int security_msg_queue_alloc(struct msg_queue *msq);
void security_msg_queue_free(struct msg_queue *msq);
@@ -1795,6 +1885,12 @@ int security_netlink_recv(struct sk_buff *skb, int cap);
int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen);
int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid);
void security_release_secctx(char *secdata, u32 seclen);
+#ifdef CONFIG_CHECKPOINT
+int security_may_restart(struct ckpt_ctx *ctx);
+int security_checkpoint_header(struct ckpt_ctx *ctx);
+#endif /* CONFIG_CHECKPOINT */
+
+char *security_get_lsm_name(void);
#else /* CONFIG_SECURITY */
struct security_mnt_opts {
@@ -1818,6 +1914,12 @@ static inline int security_init(void)
return 0;
}
+#define DEFAULT_LSM_NAME "lsm_none"
+static inline char *security_get_lsm_name(void)
+{
+ return DEFAULT_LSM_NAME;
+}
+
static inline int security_ptrace_may_access(struct task_struct *child,
unsigned int mode)
{
@@ -2202,6 +2304,19 @@ static inline int security_file_alloc(struct file *file)
return 0;
}
+static inline char *security_file_checkpoint(void *security)
+{
+ /* this shouldn't ever get called if SECURITY=n */
+ return ERR_PTR(-EINVAL);
+}
+
+static inline int security_file_restore(struct file *file, char *ctx)
+{
+ /* we're asked to recreate security contexts for an LSM which had
+ * contexts, but CONFIG_SECURITY=n now! */
+ return -EINVAL;
+}
+
static inline void security_file_free(struct file *file)
{ }
@@ -2266,6 +2381,20 @@ static inline int security_task_create(unsigned long clone_flags)
return 0;
}
+static inline char *security_cred_checkpoint(void *security)
+{
+ /* this shouldn't ever get called if SECURITY=n */
+ return ERR_PTR(-EINVAL);
+}
+
+static inline int security_cred_restore(struct file *file, struct cred *cred,
+ char *ctx)
+{
+ /* we're asked to recreate security contexts for an LSM which had
+ * contexts, but CONFIG_SECURITY=n now! */
+ return -EINVAL;
+}
+
static inline void security_cred_free(struct cred *cred)
{ }
@@ -2408,11 +2537,37 @@ static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
*secid = 0;
}
+static inline char *security_ipc_checkpoint(void *security)
+{
+ /* this shouldn't ever get called if SECURITY=n */
+ return ERR_PTR(-EINVAL);
+}
+
+static inline int security_ipc_restore(struct kern_ipc_perm *ipcp, char *ctx)
+{
+ /* we're asked to recreate security contexts for an LSM which had
+ * contexts, but CONFIG_SECURITY=n now! */
+ return -EINVAL;
+}
+
static inline int security_msg_msg_alloc(struct msg_msg *msg)
{
return 0;
}
+static inline char *security_msg_msg_checkpoint(void *security)
+{
+ /* this shouldn't ever get called if SECURITY=n */
+ return ERR_PTR(-EINVAL);
+}
+
+static inline int security_msg_msg_restore(struct msg_msg *msg, char *ctx)
+{
+ /* we're asked to recreate security contexts for an LSM which had
+ * contexts, but CONFIG_SECURITY=n now! */
+ return -EINVAL;
+}
+
static inline void security_msg_msg_free(struct msg_msg *msg)
{ }
@@ -2537,6 +2692,21 @@ static inline int security_secctx_to_secid(const char *secdata,
static inline void security_release_secctx(char *secdata, u32 seclen)
{
}
+
+#ifdef CONFIG_CHECKPOINT
+void ckpt_snarf_lsm_info(struct ckpt_ctx *ctx);
+int ckpt_write_dummy_lsm_info(struct ckpt_ctx *ctx);
+
+static inline int security_may_restart(struct ckpt_ctx *ctx)
+{
+ ckpt_snarf_lsm_info(ctx);
+ return 0;
+}
+static inline int security_checkpoint_header(struct ckpt_ctx *ctx)
+{
+ return ckpt_write_dummy_lsm_info(ctx);
+}
+#endif /* CONFIG_CHECKPOINT */
#endif /* CONFIG_SECURITY */
#ifdef CONFIG_SECURITY_NETWORK
@@ -2997,5 +3167,23 @@ static inline void free_secdata(void *secdata)
{ }
#endif /* CONFIG_SECURITY */
+#ifdef CONFIG_CHECKPOINT
+#define CKPT_SECURITY_MSG_MSG 1
+#define CKPT_SECURITY_IPC 2
+#define CKPT_SECURITY_FILE 3
+#define CKPT_SECURITY_CRED 4
+#define CKPT_SECURITY_MAX 4
+
+#ifdef CONFIG_SECURITY
+int security_checkpoint_obj(struct ckpt_ctx *ctx, void *security,
+ unsigned sectype);
+#else
+static inline int security_checkpoint_obj(struct ckpt_ctx *ctx, void *security,
+ unsigned sectype)
+{ return -1; }
+#endif /* CONFIG_SECURITY */
+
+#endif /* CONFIG_CHECKPOINT */
+
#endif /* ! __LINUX_SECURITY_H */
diff --git a/ipc/checkpoint.c b/ipc/checkpoint.c
index 8e6e9ba..c0d3f13 100644
--- a/ipc/checkpoint.c
+++ b/ipc/checkpoint.c
@@ -31,7 +31,8 @@ static char *ipc_ind_to_str[] = { "sem", "msg", "shm" };
* Checkpoint
*/
-int checkpoint_fill_ipc_perms(struct ckpt_hdr_ipc_perms *h,
+int checkpoint_fill_ipc_perms(struct ckpt_ctx *ctx,
+ struct ckpt_hdr_ipc_perms *h,
struct kern_ipc_perm *perm)
{
if (ipcperms(perm, S_IROTH))
@@ -45,6 +46,15 @@ int checkpoint_fill_ipc_perms(struct ckpt_hdr_ipc_perms *h,
h->cgid = perm->cgid;
h->mode = perm->mode & S_IRWXUGO;
h->seq = perm->seq;
+ if (perm->security) {
+ h->sec_ref = security_checkpoint_obj(ctx, perm->security,
+ CKPT_SECURITY_IPC);
+ if (h->sec_ref == -EOPNOTSUPP)
+ h->sec_ref = -1;
+ else if (h->sec_ref < 0)
+ return h->sec_ref;
+ } else
+ h->sec_ref = -1;
return 0;
}
@@ -176,7 +186,8 @@ static int validate_created_perms(struct ckpt_hdr_ipc_perms *h)
return 1;
}
-int restore_load_ipc_perms(struct ckpt_hdr_ipc_perms *h,
+int restore_load_ipc_perms(struct ckpt_ctx *ctx,
+ struct ckpt_hdr_ipc_perms *h,
struct kern_ipc_perm *perm)
{
if (h->id < 0)
@@ -205,14 +216,17 @@ int restore_load_ipc_perms(struct ckpt_hdr_ipc_perms *h,
perm->cgid = h->cgid;
perm->mode = h->mode;
perm->seq = h->seq;
- /*
- * Todo: restore perm->security.
- * At the moment it gets set by security_x_alloc() called through
- * ipcget()->ipcget_public()->ops-.getnew (->nequeue for instance)
- * We will want to ask the LSM to consider resetting the
- * checkpointed ->security, based on current_security(),
- * the checkpointed ->security, and the checkpoint file context.
- */
+
+ if ((ctx->uflags & RESTART_KEEP_LSM) && (h->sec_ref != -1)) {
+ int ret;
+ struct ckpt_stored_lsm *l = ckpt_obj_fetch(ctx, h->sec_ref,
+ CKPT_OBJ_SEC);
+ if (IS_ERR(l))
+ return PTR_ERR(l);
+ ret = security_ipc_restore(perm, l->string);
+ if (ret)
+ return ret;
+ }
return 0;
}
diff --git a/ipc/checkpoint_msg.c b/ipc/checkpoint_msg.c
index b933c19..24f4097 100644
--- a/ipc/checkpoint_msg.c
+++ b/ipc/checkpoint_msg.c
@@ -37,7 +37,7 @@ static int fill_ipc_msg_hdr(struct ckpt_ctx *ctx,
ipc_lock_by_ptr(&msq->q_perm);
- ret = checkpoint_fill_ipc_perms(&h->perms, &msq->q_perm);
+ ret = checkpoint_fill_ipc_perms(ctx, &h->perms, &msq->q_perm);
if (ret < 0)
goto unlock;
@@ -64,13 +64,23 @@ static int checkpoint_msg_contents(struct ckpt_ctx *ctx, struct msg_msg *msg)
struct msg_msgseg *seg;
int total, len;
int ret;
-
+ int sec_ref = -1;
+
+ if (msg->security) {
+ sec_ref = security_checkpoint_obj(ctx, msg->security,
+ CKPT_SECURITY_MSG_MSG);
+ if (sec_ref == -EOPNOTSUPP)
+ sec_ref = -1;
+ else if (sec_ref < 0)
+ return sec_ref;
+ }
h = ckpt_hdr_get_type(ctx, sizeof(*h), CKPT_HDR_IPC_MSG_MSG);
if (!h)
return -ENOMEM;
h->m_type = msg->m_type;
h->m_ts = msg->m_ts;
+ h->sec_ref = sec_ref;
ret = ckpt_write_obj(ctx, &h->h);
ckpt_hdr_put(ctx, h);
@@ -177,7 +187,7 @@ static int load_ipc_msg_hdr(struct ckpt_ctx *ctx,
{
int ret = 0;
- ret = restore_load_ipc_perms(&h->perms, &msq->q_perm);
+ ret = restore_load_ipc_perms(ctx, &h->perms, &msq->q_perm);
if (ret < 0)
return ret;
@@ -224,6 +234,16 @@ static struct msg_msg *restore_msg_contents_one(struct ckpt_ctx *ctx, int *clen)
msg->next = NULL;
pseg = &msg->next;
+ if ((ctx->uflags & RESTART_KEEP_LSM) && (h->sec_ref != -1)) {
+ struct ckpt_stored_lsm *l = ckpt_obj_fetch(ctx, h->sec_ref,
+ CKPT_OBJ_SEC);
+ if (IS_ERR(l))
+ return (struct msg_msg *)l;
+ ret = security_msg_msg_restore(msg, l->string);
+ if (ret)
+ return ERR_PTR(ret);
+ }
+
ret = _ckpt_read_buffer(ctx, (msg + 1), len);
if (ret < 0)
goto out;
diff --git a/ipc/checkpoint_sem.c b/ipc/checkpoint_sem.c
index 76eb2b9..53a19ed 100644
--- a/ipc/checkpoint_sem.c
+++ b/ipc/checkpoint_sem.c
@@ -37,7 +37,7 @@ static int fill_ipc_sem_hdr(struct ckpt_ctx *ctx,
ipc_lock_by_ptr(&sem->sem_perm);
- ret = checkpoint_fill_ipc_perms(&h->perms, &sem->sem_perm);
+ ret = checkpoint_fill_ipc_perms(ctx, &h->perms, &sem->sem_perm);
if (ret < 0)
goto unlock;
@@ -113,7 +113,7 @@ static int load_ipc_sem_hdr(struct ckpt_ctx *ctx,
{
int ret = 0;
- ret = restore_load_ipc_perms(&h->perms, &sem->sem_perm);
+ ret = restore_load_ipc_perms(ctx, &h->perms, &sem->sem_perm);
if (ret < 0)
return ret;
diff --git a/ipc/checkpoint_shm.c b/ipc/checkpoint_shm.c
index 826e430..01091d9 100644
--- a/ipc/checkpoint_shm.c
+++ b/ipc/checkpoint_shm.c
@@ -41,7 +41,7 @@ static int fill_ipc_shm_hdr(struct ckpt_ctx *ctx,
ipc_lock_by_ptr(&shp->shm_perm);
- ret = checkpoint_fill_ipc_perms(&h->perms, &shp->shm_perm);
+ ret = checkpoint_fill_ipc_perms(ctx, &h->perms, &shp->shm_perm);
if (ret < 0)
goto unlock;
@@ -165,7 +165,7 @@ static int load_ipc_shm_hdr(struct ckpt_ctx *ctx,
{
int ret;
- ret = restore_load_ipc_perms(&h->perms, &shp->shm_perm);
+ ret = restore_load_ipc_perms(ctx, &h->perms, &shp->shm_perm);
if (ret < 0)
return ret;
diff --git a/ipc/util.h b/ipc/util.h
index ba080de..ce34de0 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -199,9 +199,11 @@ void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp);
#ifdef CONFIG_CHECKPOINT
-extern int checkpoint_fill_ipc_perms(struct ckpt_hdr_ipc_perms *h,
+extern int checkpoint_fill_ipc_perms(struct ckpt_ctx *ctx,
+ struct ckpt_hdr_ipc_perms *h,
struct kern_ipc_perm *perm);
-extern int restore_load_ipc_perms(struct ckpt_hdr_ipc_perms *h,
+extern int restore_load_ipc_perms(struct ckpt_ctx *ctx,
+ struct ckpt_hdr_ipc_perms *h,
struct kern_ipc_perm *perm);
extern int ckpt_collect_ipc_shm(int id, void *p, void *data);
diff --git a/kernel/cred.c b/kernel/cred.c
index 9710cae..06bc676 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -709,7 +709,7 @@ int cred_setfsgid(struct cred *new, gid_t gid, gid_t *old_fsgid)
static int do_checkpoint_cred(struct ckpt_ctx *ctx, struct cred *cred)
{
int ret;
- int groupinfo_ref, user_ref;
+ int groupinfo_ref, user_ref, sec_ref = -1;
struct ckpt_hdr_cred *h;
groupinfo_ref = checkpoint_obj(ctx, cred->group_info,
@@ -719,6 +719,14 @@ static int do_checkpoint_cred(struct ckpt_ctx *ctx, struct cred *cred)
user_ref = checkpoint_obj(ctx, cred->user, CKPT_OBJ_USER);
if (user_ref < 0)
return user_ref;
+#ifdef CONFIG_SECURITY
+ sec_ref = security_checkpoint_obj(ctx, cred->security,
+ CKPT_SECURITY_CRED);
+ if (sec_ref == -EOPNOTSUPP)
+ sec_ref = -1;
+ else if (sec_ref < 0)
+ return sec_ref;
+#endif /* else cred->security doesn't exist and sec_ref = -1 */
h = ckpt_hdr_get_type(ctx, sizeof(*h), CKPT_HDR_CRED);
if (!h)
@@ -733,6 +741,7 @@ static int do_checkpoint_cred(struct ckpt_ctx *ctx, struct cred *cred)
h->sgid = cred->sgid;
h->egid = cred->egid;
h->fsgid = cred->fsgid;
+ h->sec_ref = sec_ref;
checkpoint_capabilities(&h->cap_s, cred);
@@ -806,6 +815,15 @@ static struct cred *do_restore_cred(struct ckpt_ctx *ctx)
ret = cred_setfsgid(cred, h->fsgid, &oldgid);
if (oldgid != h->fsgid && ret < 0)
goto err_putcred;
+ if ((ctx->uflags & RESTART_KEEP_LSM) && (h->sec_ref != -1)) {
+ struct ckpt_stored_lsm *l = ckpt_obj_fetch(ctx, h->sec_ref,
+ CKPT_OBJ_SEC);
+ if (IS_ERR(l))
+ return (struct cred *)l;
+ ret = security_cred_restore(ctx->file, cred, l->string);
+ if (ret)
+ goto err_putcred;
+ }
ret = restore_capabilities(&h->cap_s, cred);
if (ret)
goto err_putcred;
diff --git a/security/capability.c b/security/capability.c
index 88f752e..4e82df8 100644
--- a/security/capability.c
+++ b/security/capability.c
@@ -315,6 +315,16 @@ static int cap_file_permission(struct file *file, int mask)
return 0;
}
+static inline char *cap_file_checkpoint(void *security)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
+
+static int cap_file_restore(struct file *file, char *ctx)
+{
+ return -EOPNOTSUPP;
+}
+
static int cap_file_alloc_security(struct file *file)
{
return 0;
@@ -373,6 +383,16 @@ static int cap_task_create(unsigned long clone_flags)
return 0;
}
+static char *cap_cred_checkpoint(void *security)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
+
+static int cap_cred_restore(struct file *file, struct cred *cred, char *ctx)
+{
+ return -EOPNOTSUPP;
+}
+
static void cap_cred_free(struct cred *cred)
{
}
@@ -476,11 +496,31 @@ static void cap_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
*secid = 0;
}
+static char *cap_ipc_checkpoint(void *security)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
+
+static int cap_ipc_restore(struct kern_ipc_perm *ipcp, char *ctx)
+{
+ return -EOPNOTSUPP;
+}
+
static int cap_msg_msg_alloc_security(struct msg_msg *msg)
{
return 0;
}
+static inline char *cap_msg_msg_checkpoint(void *security)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
+
+static int cap_msg_msg_restore(struct msg_msg *msg, char *ctx)
+{
+ return -EOPNOTSUPP;
+}
+
static void cap_msg_msg_free_security(struct msg_msg *msg)
{
}
@@ -792,6 +832,28 @@ static void cap_release_secctx(char *secdata, u32 seclen)
{
}
+#ifdef CONFIG_CHECKPOINT
+void ckpt_snarf_lsm_info(struct ckpt_ctx *ctx);
+int ckpt_write_dummy_lsm_info(struct ckpt_ctx *ctx);
+static int cap_may_restart(struct ckpt_ctx *ctx)
+{
+ /*
+ * Note that all construction of kernel resources, credentials,
+ * etc is already authorized per the caller's credentials. This
+ * hook is intended for the LSM to make further decisions about
+ * a task not being allowed to restart at all, for instance if
+ * the policy has changed since checkpoint.
+ */
+ ckpt_snarf_lsm_info(ctx);
+ return 0;
+}
+
+static int cap_checkpoint_header(struct ckpt_ctx *ctx)
+{
+ return ckpt_write_dummy_lsm_info(ctx);
+}
+#endif
+
#ifdef CONFIG_KEYS
static int cap_key_alloc(struct key *key, const struct cred *cred,
unsigned long flags)
@@ -928,6 +990,8 @@ void security_fixup_ops(struct security_operations *ops)
set_to_cap_if_null(ops, path_truncate);
#endif
set_to_cap_if_null(ops, file_permission);
+ set_to_cap_if_null(ops, file_checkpoint);
+ set_to_cap_if_null(ops, file_restore);
set_to_cap_if_null(ops, file_alloc_security);
set_to_cap_if_null(ops, file_free_security);
set_to_cap_if_null(ops, file_ioctl);
@@ -940,6 +1004,8 @@ void security_fixup_ops(struct security_operations *ops)
set_to_cap_if_null(ops, file_receive);
set_to_cap_if_null(ops, dentry_open);
set_to_cap_if_null(ops, task_create);
+ set_to_cap_if_null(ops, cred_checkpoint);
+ set_to_cap_if_null(ops, cred_restore);
set_to_cap_if_null(ops, cred_free);
set_to_cap_if_null(ops, cred_prepare);
set_to_cap_if_null(ops, cred_commit);
@@ -966,7 +1032,11 @@ void security_fixup_ops(struct security_operations *ops)
set_to_cap_if_null(ops, task_to_inode);
set_to_cap_if_null(ops, ipc_permission);
set_to_cap_if_null(ops, ipc_getsecid);
+ set_to_cap_if_null(ops, ipc_checkpoint);
+ set_to_cap_if_null(ops, ipc_restore);
set_to_cap_if_null(ops, msg_msg_alloc_security);
+ set_to_cap_if_null(ops, msg_msg_checkpoint);
+ set_to_cap_if_null(ops, msg_msg_restore);
set_to_cap_if_null(ops, msg_msg_free_security);
set_to_cap_if_null(ops, msg_queue_alloc_security);
set_to_cap_if_null(ops, msg_queue_free_security);
@@ -992,6 +1062,10 @@ void security_fixup_ops(struct security_operations *ops)
set_to_cap_if_null(ops, secid_to_secctx);
set_to_cap_if_null(ops, secctx_to_secid);
set_to_cap_if_null(ops, release_secctx);
+#ifdef CONFIG_CHECKPOINT
+ set_to_cap_if_null(ops, may_restart);
+ set_to_cap_if_null(ops, checkpoint_header);
+#endif
#ifdef CONFIG_SECURITY_NETWORK
set_to_cap_if_null(ops, unix_stream_connect);
set_to_cap_if_null(ops, unix_may_send);
diff --git a/security/security.c b/security/security.c
index dc7674f..52647e0 100644
--- a/security/security.c
+++ b/security/security.c
@@ -122,6 +122,11 @@ int register_security(struct security_operations *ops)
return 0;
}
+char *security_get_lsm_name(void)
+{
+ return security_ops->name;
+}
+
/* Security operations */
int security_ptrace_may_access(struct task_struct *child, unsigned int mode)
@@ -625,6 +630,16 @@ int security_file_alloc(struct file *file)
return security_ops->file_alloc_security(file);
}
+char *security_file_checkpoint(void *security)
+{
+ return security_ops->file_checkpoint(security);
+}
+
+int security_file_restore(struct file *file, char *ctx)
+{
+ return security_ops->file_restore(file, ctx);
+}
+
void security_file_free(struct file *file)
{
security_ops->file_free_security(file);
@@ -684,6 +699,16 @@ int security_task_create(unsigned long clone_flags)
return security_ops->task_create(clone_flags);
}
+char *security_cred_checkpoint(void *security)
+{
+ return security_ops->cred_checkpoint(security);
+}
+
+int security_cred_restore(struct file *file, struct cred *cred, char *ctx)
+{
+ return security_ops->cred_restore(file, cred, ctx);
+}
+
void security_cred_free(struct cred *cred)
{
security_ops->cred_free(cred);
@@ -819,11 +844,31 @@ void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
security_ops->ipc_getsecid(ipcp, secid);
}
+char *security_ipc_checkpoint(void *security)
+{
+ return security_ops->ipc_checkpoint(security);
+}
+
+int security_ipc_restore(struct kern_ipc_perm *ipcp, char *ctx)
+{
+ return security_ops->ipc_restore(ipcp, ctx);
+}
+
int security_msg_msg_alloc(struct msg_msg *msg)
{
return security_ops->msg_msg_alloc_security(msg);
}
+char *security_msg_msg_checkpoint(void *security)
+{
+ return security_ops->msg_msg_checkpoint(security);
+}
+
+int security_msg_msg_restore(struct msg_msg *msg, char *ctx)
+{
+ return security_ops->msg_msg_restore(msg, ctx);
+}
+
void security_msg_msg_free(struct msg_msg *msg)
{
security_ops->msg_msg_free_security(msg);
@@ -959,6 +1004,20 @@ void security_release_secctx(char *secdata, u32 seclen)
}
EXPORT_SYMBOL(security_release_secctx);
+#ifdef CONFIG_CHECKPOINT
+int security_may_restart(struct ckpt_ctx *ctx)
+{
+ return security_ops->may_restart(ctx);
+}
+EXPORT_SYMBOL(security_may_restart);
+
+int security_checkpoint_header(struct ckpt_ctx *ctx)
+{
+ return security_ops->checkpoint_header(ctx);
+}
+EXPORT_SYMBOL(security_checkpoint_header);
+#endif
+
#ifdef CONFIG_SECURITY_NETWORK
int security_unix_stream_connect(struct socket *sock, struct socket *other,
@@ -1244,3 +1303,75 @@ int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule,
}
#endif /* CONFIG_AUDIT */
+
+#ifdef CONFIG_CHECKPOINT
+
+#include <linux/checkpoint.h>
+
+/**
+ * security_checkpoint_obj - if first checkpoint of this void* security,
+ * then 1. ask the LSM for a string representing the context, 2. checkpoint
+ * that string
+ * @ctx: the checkpoint context
+ * @security: the void* security being checkpointed
+ * @sectype: indicates the type of object, because LSMs can (and do) store
+ * different types of data for different types of objects.
+ *
+ * Returns the objref of the checkpointed ckpt_stored_lsm representing the
+ * context, or -error on error.
+ *
+ * This is only used at checkpoint of course.
+ */
+int security_checkpoint_obj(struct ckpt_ctx *ctx, void *security,
+ unsigned sectype)
+{
+ int strref;
+ struct ckpt_stored_lsm *l;
+ char *str;
+ int len;
+
+ /*
+ * to simplify the LSM code, short-cut a null security
+ * here.
+ */
+ if (!security)
+ return -EOPNOTSUPP;
+
+ switch (sectype) {
+ case CKPT_SECURITY_MSG_MSG:
+ str = security_msg_msg_checkpoint(security);
+ break;
+ case CKPT_SECURITY_IPC:
+ str = security_ipc_checkpoint(security);
+ break;
+ case CKPT_SECURITY_FILE:
+ str = security_file_checkpoint(security);
+ break;
+ case CKPT_SECURITY_CRED:
+ str = security_cred_checkpoint(security);
+ break;
+ default:
+ str = ERR_PTR(-EINVAL);
+ break;
+ }
+ /* str will be alloc'ed for us by the LSM. We will free it when
+ * we clear out our hashtable */
+ if (IS_ERR(str))
+ return PTR_ERR(str);
+
+ len = strlen(str);
+ l = kzalloc(sizeof(*l) + len + 1, GFP_KERNEL);
+ if (!l) {
+ kfree(str);
+ return -ENOMEM;
+ }
+ kref_init(&l->kref);
+ l->sectype = sectype;
+ l->string = str;
+
+ strref = checkpoint_obj(ctx, l, CKPT_OBJ_SEC);
+ /* do we need to free l if strref was err? */
+ return strref;
+}
+
+#endif
--
1.6.1
--
This message was distributed to subscribers of the selinux mailing list.
If you no longer wish to subscribe, send mail to majordomo@tycho.nsa.gov with
the words "unsubscribe selinux" without quotes as the message.
^ permalink raw reply related [flat|nested] 22+ messages in thread
* [PATCH 1/1] restart: accept the lsm_name field in header and add -k flag
[not found] ` <20091002034916.GA16871-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
@ 2009-10-02 3:51 ` Serge E. Hallyn
[not found] ` <20091002035157.GA16920-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
2009-10-02 20:57 ` [PATCH 1/3] cr: add generic LSM c/r support (v4) Oren Laadan
1 sibling, 1 reply; 22+ messages in thread
From: Serge E. Hallyn @ 2009-10-02 3:51 UTC (permalink / raw)
To: Linux Containers
The checkpoint file header now has an 11-character string
containing the name of the active LSM, following the uts
info, and a variable length buffer type conaining LSM-specific
version information (for instance a sha1sum of policy).
Handle these.
Also add a -k (--keeplsm) flag to tell restart to set the
RESTART_KEEP_LSM flag to sys_restart().
Signed-off-by: Serge E. Hallyn <serue-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
---
restart.c | 32 +++++++++++++++++++++++++++++++-
1 files changed, 31 insertions(+), 1 deletions(-)
diff --git a/restart.c b/restart.c
index b810ca9..44ae252 100644
--- a/restart.c
+++ b/restart.c
@@ -68,6 +68,7 @@ static char usage_str[] =
" --signal=SIG send SIG to root task on SIGINT (default: SIGKILL\n"
" to container root, SIGINT otherwise)\n"
" -w,--wait wait for root task to termiate (default)\n"
+" -k,--keeplsm Try to recreate original LSM labels on all objects\n"
" --show-status show exit status of root task (implies -w)\n"
" --copy-status imitate exit status of root task (implies -w)\n"
" -W,--no-wait do not wait for root task to terminate\n"
@@ -349,6 +350,8 @@ struct args {
char *input;
};
+int keep_lsm;
+
static void usage(char *str)
{
fprintf(stderr, "%s", str);
@@ -377,6 +380,7 @@ static void parse_args(struct args *args, int argc, char *argv[])
{ "self", no_argument, NULL, 6},
{ "signal", required_argument, NULL, 4 },
{ "inspect", no_argument, NULL, 5 },
+ { "keeplsm", no_argument, NULL, 'k' },
{ "input", required_argument, NULL, 'i' },
{ "root", required_argument, NULL, 'r' },
{ "wait", no_argument, NULL, 'w' },
@@ -388,7 +392,7 @@ static void parse_args(struct args *args, int argc, char *argv[])
{ "debug", no_argument, NULL, 'd' },
{ NULL, 0, NULL, 0 }
};
- static char optc[] = "hdvpPwWF:r:i:";
+ static char optc[] = "hdvpkPwWF:r:i:";
int sig;
@@ -443,6 +447,9 @@ static void parse_args(struct args *args, int argc, char *argv[])
case 'w':
args->wait = 1;
break;
+ case 'k':
+ keep_lsm = RESTART_KEEP_LSM;
+ break;
case 'W':
args->wait = 0;
break;
@@ -927,6 +934,7 @@ static int ckpt_coordinator(struct ckpt_ctx *ctx)
if (ctx->args->freezer)
flags |= RESTART_FROZEN;
+ flags |= keep_lsm;
ret = restart(root_pid, STDIN_FILENO, flags);
if (ret < 0) {
@@ -1581,6 +1589,7 @@ static int ckpt_make_tree(struct ckpt_ctx *ctx, struct task *task)
if (task->flags & (TASK_GHOST | TASK_DEAD))
flags |= RESTART_GHOST;
+ flags |= keep_lsm;
/* on success this doesn't return */
ckpt_dbg("about to call sys_restart(), flags %#lx\n", flags);
ret = restart(0, STDIN_FILENO, flags);
@@ -2057,6 +2066,7 @@ static int ckpt_read_obj_buffer(struct ckpt_ctx *ctx, void *buf, int n)
* read/write the checkpoint image: similar to in-kernel code
*/
+#define SECURITY_NAME_MAX 20
static int ckpt_read_header(struct ckpt_ctx *ctx)
{
struct ckpt_hdr_header *h;
@@ -2090,6 +2100,16 @@ static int ckpt_read_header(struct ckpt_ctx *ctx)
if (ret < 0)
return ret;
+ ptr += ((struct ckpt_hdr *) ptr)->len;
+ ret = ckpt_read_obj_buffer(ctx, ptr, SECURITY_NAME_MAX + 1);
+ if (ret < 0)
+ return ret;
+
+ ptr += ((struct ckpt_hdr *) ptr)->len;
+ ret = ckpt_read_obj_type(ctx, ptr, 200, CKPT_HDR_LSM_INFO);
+ if (ret < 0)
+ return ret;
+
/* FIXME: skip version validation for now */
return 0;
@@ -2169,6 +2189,16 @@ static int ckpt_write_header(struct ckpt_ctx *ctx)
ptr += ((struct ckpt_hdr *) ptr)->len;
ret = ckpt_write_obj(ctx, (struct ckpt_hdr *) ptr);
+ if (ret < 0)
+ return ret;
+ ptr += ((struct ckpt_hdr *) ptr)->len;
+ ret = ckpt_write_obj(ctx, (struct ckpt_hdr *) ptr);
+ if (ret < 0)
+ return ret;
+
+ ptr += ((struct ckpt_hdr *) ptr)->len;
+ ret = ckpt_write_obj(ctx, (struct ckpt_hdr *) ptr);
+
return ret;
}
--
1.6.1.1
^ permalink raw reply related [flat|nested] 22+ messages in thread
* [PATCH 2/3] cr: add smack support to lsm c/r (v4)
2009-10-02 3:49 ` Serge E. Hallyn
(?)
@ 2009-10-02 3:52 ` Serge E. Hallyn
-1 siblings, 0 replies; 22+ messages in thread
From: Serge E. Hallyn @ 2009-10-02 3:52 UTC (permalink / raw)
To: Linux Containers; +Cc: linux-security-module, Casey Schaufler
Documentation/checkpoint/readme.txt begins:
"""
Application checkpoint/restart is the ability to save the state
of a running application so that it can later resume its execution
from the time at which it was checkpointed.
"""
This patch implements checkpoint and restore of Smack security
labels. The rules are the same as in previous versions:
1. when objects are created during restore() they are
automatically labeled with current_security().
2. if there was a label checkpointed with the object,
and that label != current_security() (which is the
same as obj->security), then the object is relabeled
if the sys_restart() caller has CAP_MAC_ADMIN.
Otherwise we return -EPERM.
This has been tested by checkpointing tasks under labels
_, vs1, and vs2, and restarting from tasks under _, vs1,
and vs2, with and without CAP_MAC_ADMIN in the bounding
set, and with and without the '-k' (keep_lsm) flag to mktree.
Expected results:
#shell 1:
echo vs1 > /proc/self/attr/current
ckpt > out
echo vs2 > /proc/self/attr/current
mktree -F /cgroup/2 < out
(frozen)
# shell 2:
cat /proc/`pidof ckpt`/attr/current
vs2
echo THAWED > /cgroup/2/freezer.state
# shell 1:
mktree -k -F /cgroup/2 < out
(frozen)
# shell 2:
cat /proc/`pidof ckpt`/attr/current
vs1
echo THAWED > /cgroup/2/freezer.state
# shell 1:
capsh --drop=cap_mac_admin --
mktree -k -F /cgroup/2 < out
(permission denied)
There are testcases in git://git.sr71.net/~hallyn/cr_tests.git
under cr_tests/smack, which automate the above (and pass).
Changelog:
sep 3: add a version to smack lsm, accessible through
/smack/version (Casey and Serge)
sep 10: rename xyz_get_ctx() to xyz_checkpoint()
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
---
checkpoint/restart.c | 1 +
security/smack/smack.h | 1 +
security/smack/smack_lsm.c | 141 ++++++++++++++++++++++++++++++++++++++++++++
security/smack/smackfs.c | 83 ++++++++++++++++++++++++++
4 files changed, 226 insertions(+), 0 deletions(-)
diff --git a/checkpoint/restart.c b/checkpoint/restart.c
index bba2b45..55bd2b5 100644
--- a/checkpoint/restart.c
+++ b/checkpoint/restart.c
@@ -470,6 +470,7 @@ static int restore_read_header(struct ckpt_ctx *ctx)
}
/* to be implemented later, per-lsm */
if (strcmp(ctx->lsm_name, "lsm_none") != 0 &&
+ strcmp(ctx->lsm_name, "smack") != 0 &&
strcmp(ctx->lsm_name, "default") != 0) {
pr_warning("c/r: RESTART_KEEP_LSM unsupported for %s\n",
ctx->lsm_name);
diff --git a/security/smack/smack.h b/security/smack/smack.h
index 243bec1..b5c1ce6 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -216,6 +216,7 @@ u32 smack_to_secid(const char *);
extern int smack_cipso_direct;
extern char *smack_net_ambient;
extern char *smack_onlycap;
+extern char *smack_version;
extern const char *smack_cipso_option;
extern struct smack_known smack_known_floor;
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 0023182..1058de4 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -27,6 +27,7 @@
#include <linux/udp.h>
#include <linux/mutex.h>
#include <linux/pipe_fs_i.h>
+#include <linux/checkpoint.h>
#include <net/netlabel.h>
#include <net/cipso_ipv4.h>
#include <linux/audit.h>
@@ -892,6 +893,28 @@ static int smack_file_permission(struct file *file, int mask)
return 0;
}
+static inline char *smack_file_checkpoint(void *security)
+{
+ return kstrdup((char *)security, GFP_KERNEL);
+}
+
+static inline int smack_file_restore(struct file *file, char *ctx)
+{
+ char *newsmack = smk_import(ctx, 0);
+
+ if (newsmack == NULL)
+ return -EINVAL;
+ /* I think by definition, file->f_security == current_security
+ * right now, but let's assume somehow it might not be */
+ if (newsmack == file->f_security)
+ return 0;
+ if (!capable(CAP_MAC_ADMIN))
+ return -EPERM;
+ file->f_security = newsmack;
+
+ return 0;
+}
+
/**
* smack_file_alloc_security - assign a file security blob
* @file: the object
@@ -1079,6 +1102,27 @@ static int smack_file_receive(struct file *file)
* Task hooks
*/
+static inline char *smack_cred_checkpoint(void *security)
+{
+ return kstrdup((char *)security, GFP_KERNEL);
+}
+
+static inline int smack_cred_restore(struct file *file, struct cred *cred,
+ char *ctx)
+{
+ char *newsmack = smk_import(ctx, 0);
+
+ if (newsmack == NULL)
+ return -EINVAL;
+ if (newsmack == cred->security)
+ return 0;
+ if (!capable(CAP_MAC_ADMIN))
+ return -EPERM;
+ cred->security = newsmack;
+
+ return 0;
+}
+
/**
* smack_cred_free - "free" task-level security credentials
* @cred: the credentials in question
@@ -1742,6 +1786,26 @@ static int smack_msg_msg_alloc_security(struct msg_msg *msg)
return 0;
}
+static inline char *smack_msg_msg_checkpoint(void *security)
+{
+ return kstrdup((char *)security, GFP_KERNEL);
+}
+
+static inline int smack_msg_msg_restore(struct msg_msg *msg, char *ctx)
+{
+ char *newsmack = smk_import(ctx, 0);
+
+ if (newsmack == NULL)
+ return -EINVAL;
+ if (newsmack == msg->security)
+ return 0;
+ if (!capable(CAP_MAC_ADMIN))
+ return -EPERM;
+ msg->security = newsmack;
+
+ return 0;
+}
+
/**
* smack_msg_msg_free_security - Clear the security blob for msg_msg
* @msg: the object
@@ -2175,6 +2239,26 @@ static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
*secid = smack_to_secid(smack);
}
+static inline char *smack_ipc_checkpoint(void *security)
+{
+ return kstrdup((char *)security, GFP_KERNEL);
+}
+
+static inline int smack_ipc_restore(struct kern_ipc_perm *ipcp, char *ctx)
+{
+ char *newsmack = smk_import(ctx, 0);
+
+ if (newsmack == NULL)
+ return -EINVAL;
+ if (newsmack == ipcp->security)
+ return 0;
+ if (!capable(CAP_MAC_ADMIN))
+ return -EPERM;
+ ipcp->security = newsmack;
+
+ return 0;
+}
+
/**
* smack_d_instantiate - Make sure the blob is correct on an inode
* @opt_dentry: unused
@@ -3029,6 +3113,51 @@ static void smack_release_secctx(char *secdata, u32 seclen)
{
}
+#ifdef CONFIG_CHECKPOINT
+
+static int smack_may_restart(struct ckpt_ctx *ctx)
+{
+ struct ckpt_hdr *chp;
+ char *saved_version;
+ int ret = 0;
+
+ chp = ckpt_read_buf_type(ctx, CKPT_LSM_INFO_LEN, CKPT_HDR_LSM_INFO);
+ if (IS_ERR(chp))
+ return PTR_ERR(chp);
+
+ /*
+ * After the checkpoint header comes the null terminated
+ * Smack "policy" version. This will usually be the
+ * floor label "_".
+ */
+ saved_version = (char *)(chp + 1);
+
+ /*
+ * Of course, it is possible that a "policy" version mismatch
+ * is not considered threatening.
+ */
+ if (!(ctx->uflags & RESTART_KEEP_LSM))
+ goto skip;
+
+ if (strcmp(saved_version, smack_version) != 0) {
+ ckpt_debug("Smack version at checkpoint was"
+ "\"%s\", now is \"%s\".\n",
+ saved_version, smack_version);
+ ret = -EINVAL;
+ }
+skip:
+ ckpt_hdr_put(ctx, chp);
+ return ret;
+}
+
+static int smack_checkpoint_header(struct ckpt_ctx *ctx)
+{
+ return ckpt_write_obj_type(ctx, smack_version,
+ strlen(smack_version) + 1,
+ CKPT_HDR_LSM_INFO);
+}
+#endif
+
struct security_operations smack_ops = {
.name = "smack",
@@ -3064,6 +3193,8 @@ struct security_operations smack_ops = {
.inode_getsecid = smack_inode_getsecid,
.file_permission = smack_file_permission,
+ .file_checkpoint = smack_file_checkpoint,
+ .file_restore = smack_file_restore,
.file_alloc_security = smack_file_alloc_security,
.file_free_security = smack_file_free_security,
.file_ioctl = smack_file_ioctl,
@@ -3073,6 +3204,8 @@ struct security_operations smack_ops = {
.file_send_sigiotask = smack_file_send_sigiotask,
.file_receive = smack_file_receive,
+ .cred_checkpoint = smack_cred_checkpoint,
+ .cred_restore = smack_cred_restore,
.cred_free = smack_cred_free,
.cred_prepare = smack_cred_prepare,
.cred_commit = smack_cred_commit,
@@ -3094,8 +3227,12 @@ struct security_operations smack_ops = {
.ipc_permission = smack_ipc_permission,
.ipc_getsecid = smack_ipc_getsecid,
+ .ipc_checkpoint = smack_ipc_checkpoint,
+ .ipc_restore = smack_ipc_restore,
.msg_msg_alloc_security = smack_msg_msg_alloc_security,
+ .msg_msg_checkpoint = smack_msg_msg_checkpoint,
+ .msg_msg_restore = smack_msg_msg_restore,
.msg_msg_free_security = smack_msg_msg_free_security,
.msg_queue_alloc_security = smack_msg_queue_alloc_security,
@@ -3155,6 +3292,10 @@ struct security_operations smack_ops = {
.secid_to_secctx = smack_secid_to_secctx,
.secctx_to_secid = smack_secctx_to_secid,
.release_secctx = smack_release_secctx,
+#ifdef CONFIG_CHECKPOINT
+ .may_restart = smack_may_restart,
+ .checkpoint_header = smack_checkpoint_header,
+#endif
};
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index f83a809..0f0d5aa 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -42,6 +42,7 @@ enum smk_inos {
SMK_NETLBLADDR = 8, /* single label hosts */
SMK_ONLYCAP = 9, /* the only "capable" label */
SMK_LOGGING = 10, /* logging */
+ SMK_VERSION = 11, /* logging */
};
/*
@@ -51,6 +52,7 @@ static DEFINE_MUTEX(smack_list_lock);
static DEFINE_MUTEX(smack_cipso_lock);
static DEFINE_MUTEX(smack_ambient_lock);
static DEFINE_MUTEX(smk_netlbladdr_lock);
+static DEFINE_MUTEX(smack_version_lock);
/*
* This is the "ambient" label for network traffic.
@@ -60,6 +62,16 @@ static DEFINE_MUTEX(smk_netlbladdr_lock);
char *smack_net_ambient = smack_known_floor.smk_known;
/*
+ * This is the policy version. In the interest of simplicity the
+ * policy version is a string that meets all of the requirements
+ * of a Smack label. This is enforced by the expedient of
+ * importing it like a label. The policy version is thus always
+ * also a valid label on the system. This may prove useful under
+ * some as yet undiscovered circumstance.
+ */
+char *smack_version = smack_known_floor.smk_known;
+
+/*
* This is the level in a CIPSO header that indicates a
* smack label is contained directly in the category set.
* It can be reset via smackfs/direct
@@ -1255,6 +1267,75 @@ static const struct file_operations smk_logging_ops = {
.read = smk_read_logging,
.write = smk_write_logging,
};
+
+#define SMK_VERSIONLEN 12
+/**
+ * smk_read_version - read() for /smack/version
+ * @filp: file pointer, not actually used
+ * @buf: where to put the result
+ * @cn: maximum to send along
+ * @ppos: where to start
+ *
+ * Returns number of bytes read or error code, as appropriate
+ */
+static ssize_t smk_read_version(struct file *filp, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ int rc;
+
+ if (*ppos != 0)
+ return 0;
+
+ mutex_lock(&smack_version_lock);
+
+ rc = simple_read_from_buffer(buf, count, ppos, smack_version,
+ strlen(smack_version) + 1);
+
+ mutex_unlock(&smack_version_lock);
+
+ return rc;
+}
+
+/**
+ * smk_write_version - write() for /smack/version
+ * @file: file pointer, not actually used
+ * @buf: where to get the data from
+ * @count: bytes sent
+ * @ppos: where to start
+ *
+ * Returns number of bytes written or error code, as appropriate
+ */
+static ssize_t smk_write_version(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ char *smack;
+ char in[SMK_LABELLEN];
+
+ if (!capable(CAP_MAC_ADMIN))
+ return -EPERM;
+
+ if (count >= SMK_LABELLEN)
+ return -EINVAL;
+
+ if (copy_from_user(in, buf, count) != 0)
+ return -EFAULT;
+
+ smack = smk_import(in, count);
+ if (smack == NULL)
+ return -EINVAL;
+
+ mutex_lock(&smack_version_lock);
+ smack_version = smack;
+ mutex_unlock(&smack_version_lock);
+
+ return count;
+}
+
+static const struct file_operations smk_version_ops = {
+ .read = smk_read_version,
+ .write = smk_write_version,
+};
+
/**
* smk_fill_super - fill the /smackfs superblock
* @sb: the empty superblock
@@ -1287,6 +1368,8 @@ static int smk_fill_super(struct super_block *sb, void *data, int silent)
{"onlycap", &smk_onlycap_ops, S_IRUGO|S_IWUSR},
[SMK_LOGGING] =
{"logging", &smk_logging_ops, S_IRUGO|S_IWUSR},
+ [SMK_VERSION] =
+ {"version", &smk_version_ops, S_IRUGO|S_IWUSR},
/* last one */ {""}
};
--
1.6.1
^ permalink raw reply related [flat|nested] 22+ messages in thread
* [PATCH 3/3] cr: add selinux support (v4)
2009-10-02 3:49 ` Serge E. Hallyn
@ 2009-10-02 3:52 ` Serge E. Hallyn
-1 siblings, 0 replies; 22+ messages in thread
From: Serge E. Hallyn @ 2009-10-02 3:52 UTC (permalink / raw)
To: Linux Containers; +Cc: linux-security-module, SELinux, Stephen Smalley
Documentation/checkpoint/readme.txt begins:
"""
Application checkpoint/restart is the ability to save the state
of a running application so that it can later resume its execution
from the time at which it was checkpointed.
"""
This patch adds the ability to checkpoint and restore selinux
contexts for tasks, open files, and sysvipc objects. Contexts
are checkpointed as strings. For tasks and files, where a security
struct actually points to several contexts, all contexts are
written out in one string, separated by ':::'.
The default behaviors are to checkpoint contexts, but not to
restore them. To attempt to restore them, sys_restart() must
be given the RESTART_KEEP_LSM flag. If this is given then
the caller of sys_restart() must have the new 'restore' permission
to the target objclass, or for instance PROCESS__SETFSCREATE to
itself to specify a create_sid.
There are some tests under cr_tests/selinux at
git://git.sr71.net/~hallyn/cr_tests.git.
A corresponding simple refpolicy (and /usr/share/selinux/devel/include)
patch is needed.
The programs to checkpoint and restart (called 'checkpoint' and
'restart') come from git://git.ncl.cs.columbia.edu/pub/git/user-cr.git.
This patch applies against the checkpoint/restart-enabled kernel
tree at git://git.ncl.cs.columbia.edu/pub/git/linux-cr.git/.
Changelog:
oct 01: Remove some debugging that is redundant with
avc log data.
sep 10: (Most addressing suggestions by Stephen Smalley)
1. change xyz_get_ctx() to xyz_checkpoint().
2. check entrypoint permission on cred_restore
3. always dec context length by 1
4. don't allow SECSID_NULL when that's not valid
5. when SECSID_NULL is valid, restore it
6. c/r task->osid
7. Just print nothing instead of 'null' for SECSID_NULL
8. sids are __u32, as are lenghts passed to sid_to_context.
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Stephen Smalley <sds@epoch.ncsc.mil>
---
checkpoint/restart.c | 1 +
kernel/cred.c | 2 +
security/selinux/hooks.c | 371 ++++++++++++++++++++++++++
security/selinux/include/av_perm_to_string.h | 4 +
security/selinux/include/av_permissions.h | 4 +
5 files changed, 382 insertions(+), 0 deletions(-)
diff --git a/checkpoint/restart.c b/checkpoint/restart.c
index 55bd2b5..008a116 100644
--- a/checkpoint/restart.c
+++ b/checkpoint/restart.c
@@ -471,6 +471,7 @@ static int restore_read_header(struct ckpt_ctx *ctx)
/* to be implemented later, per-lsm */
if (strcmp(ctx->lsm_name, "lsm_none") != 0 &&
strcmp(ctx->lsm_name, "smack") != 0 &&
+ strcmp(ctx->lsm_name, "selinux") != 0 &&
strcmp(ctx->lsm_name, "default") != 0) {
pr_warning("c/r: RESTART_KEEP_LSM unsupported for %s\n",
ctx->lsm_name);
diff --git a/kernel/cred.c b/kernel/cred.c
index 06bc676..5eb09b8 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -732,6 +732,8 @@ static int do_checkpoint_cred(struct ckpt_ctx *ctx, struct cred *cred)
if (!h)
return -ENOMEM;
+ ckpt_debug("cred uid %d fsuid %d gid %d secref %d\n", cred->uid,
+ cred->fsuid, cred->gid, sec_ref);
h->uid = cred->uid;
h->suid = cred->suid;
h->euid = cred->euid;
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 8d8b69c..4fb8b5d 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -76,6 +76,7 @@
#include <linux/selinux.h>
#include <linux/mutex.h>
#include <linux/posix-timers.h>
+#include <linux/checkpoint.h>
#include "avc.h"
#include "objsec.h"
@@ -2961,6 +2962,108 @@ static int selinux_file_permission(struct file *file, int mask)
return selinux_revalidate_file_permission(file, mask);
}
+/*
+ * for file context, we print both the fsec->sid and fsec->fown_sid
+ * as string representations, separated by ':::'
+ * We don't touch isid - if you wanted that set you shoulda set up the
+ * fs correctly.
+ */
+static inline char *selinux_file_checkpoint(void *security)
+{
+ struct file_security_struct *fsec = security;
+ char *s1 = NULL, *s2 = NULL, *sfull;
+ __u32 len1, len2, lenfull;
+ int ret;
+
+ if (fsec->sid == 0 || fsec->fown_sid == 0)
+ return ERR_PTR(-EINVAL);
+
+ ret = security_sid_to_context(fsec->sid, &s1, &len1);
+ if (ret)
+ return ERR_PTR(ret);
+ len1--;
+ ret = security_sid_to_context(fsec->fown_sid, &s2, &len2);
+ if (ret) {
+ kfree(s1);
+ return ERR_PTR(ret);
+ }
+ len2--;
+ lenfull = len1+len2+3;
+ sfull = kmalloc(lenfull+1, GFP_KERNEL);
+ if (!sfull) {
+ sfull = ERR_PTR(-ENOMEM);
+ goto out;
+ }
+ sfull[lenfull] = '\0';
+ sprintf(sfull, "%s:::%s", s1, s2);
+
+out:
+ kfree(s1);
+ kfree(s2);
+ return sfull;
+}
+
+static inline int selinux_file_restore(struct file *file, char *ctx)
+{
+ char *s1, *s2;
+ __u32 sid1 = 0, sid2 = 0;
+ int ret = -EINVAL;
+ struct file_security_struct *fsec = file->f_security;
+
+ /*
+ * Objhash made sure the string is null-terminated.
+ * We make a copy so we can mangle it.
+ */
+ s1 = kstrdup(ctx, GFP_KERNEL);
+ if (!s1)
+ return -ENOMEM;
+ s2 = strstr(s1, ":::");
+ if (!s2)
+ goto out;
+
+ *s2 = '\0';
+ s2 += 3;
+ if (*s2 == '\0')
+ goto out;
+
+ /* SECSID_NULL is not valid for file sids */
+ if (strlen(s1) == 0 || strlen(s2) == 0)
+ goto out;
+
+ ret = security_context_to_sid(s1, strlen(s1), &sid1);
+ if (ret)
+ goto out;
+ ret = security_context_to_sid(s2, strlen(s2), &sid2);
+ if (ret)
+ goto out;
+
+ if (sid1 && fsec->sid != sid1) {
+ ret = avc_has_perm(current_sid(), sid1, SECCLASS_FILE,
+ FILE__RESTORE, NULL);
+ if (ret)
+ goto out;
+ fsec->sid = sid1;
+ }
+
+#if 0
+ /* The following must wait - bc we don't yet support
+ * c/r of fowners. */
+ if (sid2 && fsec->fown_sid != sid2) {
+ ret = avc_has_perm(current_sid(), sid2, SECCLASS_FILE,
+ FILE__FOWN_RESTORE, NULL);
+ if (ret)
+ goto out;
+ fsec->fown_sid = sid2;
+ }
+#endif
+
+ ret = 0;
+
+out:
+ kfree(s1);
+ return ret;
+}
+
static int selinux_file_alloc_security(struct file *file)
{
return file_alloc_security(file);
@@ -3219,6 +3322,187 @@ static int selinux_task_create(unsigned long clone_flags)
return current_has_perm(current, PROCESS__FORK);
}
+#define NUMTASKSIDS 6
+/*
+ * for cred context, we print:
+ * osid, sid, exec_sid, create_sid, keycreate_sid, sockcreate_sid;
+ * as string representations, separated by ':::'
+ */
+static inline char *selinux_cred_checkpoint(void *security)
+{
+ struct task_security_struct *tsec = security;
+ char *stmp, *sfull = NULL;
+ __u32 slen, runlen;
+ int i, ret;
+ __u32 sids[NUMTASKSIDS] = { tsec->osid, tsec->sid, tsec->exec_sid,
+ tsec->create_sid, tsec->keycreate_sid, tsec->sockcreate_sid };
+
+ if (sids[0] == 0 || sids[1] == 0)
+ /* SECSID_NULL is not valid for osid or sid */
+ return ERR_PTR(-EINVAL);
+
+ ret = security_sid_to_context(sids[0], &sfull, &runlen);
+ if (ret)
+ return ERR_PTR(ret);
+ runlen--;
+
+ for (i = 1; i < NUMTASKSIDS; i++) {
+ if (sids[i] == 0) {
+ stmp = NULL;
+ slen = 0;
+ } else {
+ ret = security_sid_to_context(sids[i], &stmp, &slen);
+ if (ret) {
+ kfree(sfull);
+ return ERR_PTR(ret);
+ }
+ slen--;
+ }
+ /* slen + runlen + ':::' + \0 */
+ if (slen) {
+ sfull = krealloc(sfull, slen + runlen + 3 + 1, GFP_KERNEL);
+ if (!sfull) {
+ kfree(stmp);
+ return ERR_PTR(-ENOMEM);
+ }
+ }
+ sprintf(sfull+runlen, ":::%s", stmp ? stmp : "");
+ runlen += slen + 3;
+ kfree(stmp);
+ }
+
+ return sfull;
+}
+
+static inline int credrestore_nullvalid(int which)
+{
+ int valid_array[NUMTASKSIDS] = {
+ 0, /* task osid */
+ 0, /* task sid */
+ 1, /* exec sid */
+ 1, /* create sid */
+ 1, /* keycreate_sid */
+ 1, /* sockcreate_sid */
+ };
+
+ return valid_array[which];
+}
+
+static inline int selinux_cred_restore(struct file *file, struct cred *cred,
+ char *ctx)
+{
+ char *s, *s1, *s2 = NULL;
+ int ret = -EINVAL;
+ struct task_security_struct *tsec = cred->security;
+ int i;
+ __u32 sids[NUMTASKSIDS];
+ struct inode *ctx_inode = file->f_dentry->d_inode;
+ struct avc_audit_data ad;
+
+ /*
+ * objhash made sure the string is null-terminated
+ * now we want our own copy so we can chop it up with \0's
+ */
+ s = kstrdup(ctx, GFP_KERNEL);
+ if (!s)
+ return -ENOMEM;
+
+ s1 = s;
+ for (i = 0; i < NUMTASKSIDS; i++) {
+ if (i < NUMTASKSIDS-1) {
+ ret = -EINVAL;
+ s2 = strstr(s1, ":::");
+ if (!s2)
+ goto out;
+ *s2 = '\0';
+ s2 += 3;
+ }
+ if (strlen(s1) == 0) {
+ ret = -EINVAL;
+ if (credrestore_nullvalid(i))
+ sids[i] = 0;
+ else
+ goto out;
+ } else {
+ ret = security_context_to_sid(s1, strlen(s1), &sids[i]);
+ if (ret)
+ goto out;
+ }
+ s1 = s2;
+ }
+
+ /*
+ * Check that these transitions are allowed, and effect them.
+ * XXX: Do these checks suffice?
+ */
+ if (tsec->osid != sids[0]) {
+ /*
+ * Are any security decisions made based on osid?
+ * Is it worth adding a PROCESS_RESTORE_OSID permission
+ * for this?
+ */
+ tsec->osid = sids[0];
+ }
+
+ if (tsec->sid != sids[1]) {
+ struct inode_security_struct *isec;
+ ret = avc_has_perm(current_sid(), sids[1], SECCLASS_PROCESS,
+ PROCESS__RESTORE, NULL);
+ if (ret)
+ goto out;
+ /* check whether checkpoint file type is a valid entry
+ * point to the new domain: we may want a specific
+ * 'restore_entrypoint' permission for this, but let's
+ * see if just entrypoint is deemed sufficient
+ */
+
+ AVC_AUDIT_DATA_INIT(&ad, FS);
+ ad.u.fs.path = file->f_path;
+
+ isec = ctx_inode->i_security;
+ ret = avc_has_perm(sids[1], isec->sid, SECCLASS_FILE,
+ FILE__ENTRYPOINT, &ad);
+ if (ret)
+ goto out;
+ /* TODO: do we need to check for shared state? */
+ tsec->sid = sids[1];
+ }
+
+ ret = -EPERM;
+ if (sids[2] != tsec->exec_sid) {
+ if (!current_has_perm(current, PROCESS__SETEXEC))
+ goto out;
+ tsec->exec_sid = sids[2];
+ }
+
+ if (sids[3] != tsec->create_sid) {
+ if (!current_has_perm(current, PROCESS__SETFSCREATE))
+ goto out;
+ tsec->create_sid = sids[3];
+ }
+
+ if (tsec->keycreate_sid != sids[4]) {
+ if (!current_has_perm(current, PROCESS__SETKEYCREATE))
+ goto out;
+ if (!may_create_key(sids[4], current))
+ goto out;
+ tsec->keycreate_sid = sids[4];
+ }
+
+ if (tsec->sockcreate_sid != sids[5]) {
+ if (!current_has_perm(current, PROCESS__SETSOCKCREATE))
+ goto out;
+ tsec->sockcreate_sid = sids[5];
+ }
+
+ ret = 0;
+
+out:
+ kfree(s);
+ return ret;
+}
+
+
/*
* detach and free the LSM part of a set of credentials
*/
@@ -4658,6 +4942,44 @@ static void ipc_free_security(struct kern_ipc_perm *perm)
kfree(isec);
}
+static inline char *selinux_msg_msg_checkpoint(void *security)
+{
+ struct msg_security_struct *msec = security;
+ char *s;
+ __u32 len;
+ int ret;
+
+ if (msec->sid == 0)
+ return ERR_PTR(-EINVAL);
+
+ ret = security_sid_to_context(msec->sid, &s, &len);
+ if (ret)
+ return ERR_PTR(ret);
+ return s;
+}
+
+static inline int selinux_msg_msg_restore(struct msg_msg *msg, char *ctx)
+{
+ struct msg_security_struct *msec = msg->security;
+ int ret;
+ __u32 sid = 0;
+
+ ret = security_context_to_sid(ctx, strlen(ctx), &sid);
+ if (ret)
+ return ret;
+
+ if (msec->sid == sid)
+ return 0;
+
+ ret = avc_has_perm(current_sid(), sid, SECCLASS_MSG,
+ MSG__RESTORE, NULL);
+ if (ret)
+ return ret;
+
+ msec->sid = sid;
+ return 0;
+}
+
static int msg_msg_alloc_security(struct msg_msg *msg)
{
struct msg_security_struct *msec;
@@ -5061,6 +5383,47 @@ static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
*secid = isec->sid;
}
+static inline char *selinux_ipc_checkpoint(void *security)
+{
+ struct ipc_security_struct *isec = security;
+ char *s;
+ __u32 len;
+ int ret;
+
+ if (isec->sid == 0)
+ return ERR_PTR(-EINVAL);
+
+ ret = security_sid_to_context(isec->sid, &s, &len);
+ if (ret)
+ return ERR_PTR(ret);
+ return s;
+}
+
+static inline int selinux_ipc_restore(struct kern_ipc_perm *ipcp, char *ctx)
+{
+ struct ipc_security_struct *isec = ipcp->security;
+ int ret;
+ __u32 sid = 0;
+ struct avc_audit_data ad;
+
+ ret = security_context_to_sid(ctx, strlen(ctx), &sid);
+ if (ret)
+ return ret;
+
+ if (isec->sid == sid)
+ return 0;
+
+ AVC_AUDIT_DATA_INIT(&ad, IPC);
+ ad.u.ipc_id = ipcp->key;
+ ret = avc_has_perm(current_sid(), sid, SECCLASS_IPC,
+ IPC__RESTORE, &ad);
+ if (ret)
+ return ret;
+
+ isec->sid = sid;
+ return 0;
+}
+
static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
{
if (inode)
@@ -5382,6 +5745,8 @@ static struct security_operations selinux_ops = {
.inode_getsecid = selinux_inode_getsecid,
.file_permission = selinux_file_permission,
+ .file_checkpoint = selinux_file_checkpoint,
+ .file_restore = selinux_file_restore,
.file_alloc_security = selinux_file_alloc_security,
.file_free_security = selinux_file_free_security,
.file_ioctl = selinux_file_ioctl,
@@ -5396,6 +5761,8 @@ static struct security_operations selinux_ops = {
.dentry_open = selinux_dentry_open,
.task_create = selinux_task_create,
+ .cred_checkpoint = selinux_cred_checkpoint,
+ .cred_restore = selinux_cred_restore,
.cred_free = selinux_cred_free,
.cred_prepare = selinux_cred_prepare,
.kernel_act_as = selinux_kernel_act_as,
@@ -5417,8 +5784,12 @@ static struct security_operations selinux_ops = {
.ipc_permission = selinux_ipc_permission,
.ipc_getsecid = selinux_ipc_getsecid,
+ .ipc_checkpoint = selinux_ipc_checkpoint,
+ .ipc_restore = selinux_ipc_restore,
.msg_msg_alloc_security = selinux_msg_msg_alloc_security,
+ .msg_msg_checkpoint = selinux_msg_msg_checkpoint,
+ .msg_msg_restore = selinux_msg_msg_restore,
.msg_msg_free_security = selinux_msg_msg_free_security,
.msg_queue_alloc_security = selinux_msg_queue_alloc_security,
diff --git a/security/selinux/include/av_perm_to_string.h b/security/selinux/include/av_perm_to_string.h
index 31df1d7..78945e7 100644
--- a/security/selinux/include/av_perm_to_string.h
+++ b/security/selinux/include/av_perm_to_string.h
@@ -19,6 +19,7 @@
S_(SECCLASS_FILE, FILE__ENTRYPOINT, "entrypoint")
S_(SECCLASS_FILE, FILE__EXECMOD, "execmod")
S_(SECCLASS_FILE, FILE__OPEN, "open")
+ S_(SECCLASS_FILE, FILE__RESTORE, "restore")
S_(SECCLASS_CHR_FILE, CHR_FILE__EXECUTE_NO_TRANS, "execute_no_trans")
S_(SECCLASS_CHR_FILE, CHR_FILE__ENTRYPOINT, "entrypoint")
S_(SECCLASS_CHR_FILE, CHR_FILE__EXECMOD, "execmod")
@@ -88,9 +89,11 @@
S_(SECCLASS_PROCESS, PROCESS__EXECHEAP, "execheap")
S_(SECCLASS_PROCESS, PROCESS__SETKEYCREATE, "setkeycreate")
S_(SECCLASS_PROCESS, PROCESS__SETSOCKCREATE, "setsockcreate")
+ S_(SECCLASS_PROCESS, PROCESS__RESTORE, "restore")
S_(SECCLASS_MSGQ, MSGQ__ENQUEUE, "enqueue")
S_(SECCLASS_MSG, MSG__SEND, "send")
S_(SECCLASS_MSG, MSG__RECEIVE, "receive")
+ S_(SECCLASS_MSG, MSG__RESTORE, "restore")
S_(SECCLASS_SHM, SHM__LOCK, "lock")
S_(SECCLASS_SECURITY, SECURITY__COMPUTE_AV, "compute_av")
S_(SECCLASS_SECURITY, SECURITY__COMPUTE_CREATE, "compute_create")
@@ -107,6 +110,7 @@
S_(SECCLASS_SYSTEM, SYSTEM__SYSLOG_READ, "syslog_read")
S_(SECCLASS_SYSTEM, SYSTEM__SYSLOG_MOD, "syslog_mod")
S_(SECCLASS_SYSTEM, SYSTEM__SYSLOG_CONSOLE, "syslog_console")
+ S_(SECCLASS_IPC, IPC__RESTORE, "restore")
S_(SECCLASS_CAPABILITY, CAPABILITY__CHOWN, "chown")
S_(SECCLASS_CAPABILITY, CAPABILITY__DAC_OVERRIDE, "dac_override")
S_(SECCLASS_CAPABILITY, CAPABILITY__DAC_READ_SEARCH, "dac_read_search")
diff --git a/security/selinux/include/av_permissions.h b/security/selinux/include/av_permissions.h
index d645192..8e066ac 100644
--- a/security/selinux/include/av_permissions.h
+++ b/security/selinux/include/av_permissions.h
@@ -101,6 +101,7 @@
#define FILE__ENTRYPOINT 0x00040000UL
#define FILE__EXECMOD 0x00080000UL
#define FILE__OPEN 0x00100000UL
+#define FILE__RESTORE 0x00200000UL
#define LNK_FILE__IOCTL 0x00000001UL
#define LNK_FILE__READ 0x00000002UL
#define LNK_FILE__WRITE 0x00000004UL
@@ -453,6 +454,7 @@
#define PROCESS__EXECHEAP 0x08000000UL
#define PROCESS__SETKEYCREATE 0x10000000UL
#define PROCESS__SETSOCKCREATE 0x20000000UL
+#define PROCESS__RESTORE 0x40000000UL
#define IPC__CREATE 0x00000001UL
#define IPC__DESTROY 0x00000002UL
#define IPC__GETATTR 0x00000004UL
@@ -462,6 +464,7 @@
#define IPC__ASSOCIATE 0x00000040UL
#define IPC__UNIX_READ 0x00000080UL
#define IPC__UNIX_WRITE 0x00000100UL
+#define IPC__RESTORE 0x00000200UL
#define SEM__CREATE 0x00000001UL
#define SEM__DESTROY 0x00000002UL
#define SEM__GETATTR 0x00000004UL
@@ -483,6 +486,7 @@
#define MSGQ__ENQUEUE 0x00000200UL
#define MSG__SEND 0x00000001UL
#define MSG__RECEIVE 0x00000002UL
+#define MSG__RESTORE 0x00000004UL
#define SHM__CREATE 0x00000001UL
#define SHM__DESTROY 0x00000002UL
#define SHM__GETATTR 0x00000004UL
--
1.6.1
^ permalink raw reply related [flat|nested] 22+ messages in thread
* [PATCH 3/3] cr: add selinux support (v4)
@ 2009-10-02 3:52 ` Serge E. Hallyn
0 siblings, 0 replies; 22+ messages in thread
From: Serge E. Hallyn @ 2009-10-02 3:52 UTC (permalink / raw)
To: Linux Containers; +Cc: linux-security-module, SELinux, Stephen Smalley
Documentation/checkpoint/readme.txt begins:
"""
Application checkpoint/restart is the ability to save the state
of a running application so that it can later resume its execution
from the time at which it was checkpointed.
"""
This patch adds the ability to checkpoint and restore selinux
contexts for tasks, open files, and sysvipc objects. Contexts
are checkpointed as strings. For tasks and files, where a security
struct actually points to several contexts, all contexts are
written out in one string, separated by ':::'.
The default behaviors are to checkpoint contexts, but not to
restore them. To attempt to restore them, sys_restart() must
be given the RESTART_KEEP_LSM flag. If this is given then
the caller of sys_restart() must have the new 'restore' permission
to the target objclass, or for instance PROCESS__SETFSCREATE to
itself to specify a create_sid.
There are some tests under cr_tests/selinux at
git://git.sr71.net/~hallyn/cr_tests.git.
A corresponding simple refpolicy (and /usr/share/selinux/devel/include)
patch is needed.
The programs to checkpoint and restart (called 'checkpoint' and
'restart') come from git://git.ncl.cs.columbia.edu/pub/git/user-cr.git.
This patch applies against the checkpoint/restart-enabled kernel
tree at git://git.ncl.cs.columbia.edu/pub/git/linux-cr.git/.
Changelog:
oct 01: Remove some debugging that is redundant with
avc log data.
sep 10: (Most addressing suggestions by Stephen Smalley)
1. change xyz_get_ctx() to xyz_checkpoint().
2. check entrypoint permission on cred_restore
3. always dec context length by 1
4. don't allow SECSID_NULL when that's not valid
5. when SECSID_NULL is valid, restore it
6. c/r task->osid
7. Just print nothing instead of 'null' for SECSID_NULL
8. sids are __u32, as are lenghts passed to sid_to_context.
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Stephen Smalley <sds@epoch.ncsc.mil>
---
checkpoint/restart.c | 1 +
kernel/cred.c | 2 +
security/selinux/hooks.c | 371 ++++++++++++++++++++++++++
security/selinux/include/av_perm_to_string.h | 4 +
security/selinux/include/av_permissions.h | 4 +
5 files changed, 382 insertions(+), 0 deletions(-)
diff --git a/checkpoint/restart.c b/checkpoint/restart.c
index 55bd2b5..008a116 100644
--- a/checkpoint/restart.c
+++ b/checkpoint/restart.c
@@ -471,6 +471,7 @@ static int restore_read_header(struct ckpt_ctx *ctx)
/* to be implemented later, per-lsm */
if (strcmp(ctx->lsm_name, "lsm_none") != 0 &&
strcmp(ctx->lsm_name, "smack") != 0 &&
+ strcmp(ctx->lsm_name, "selinux") != 0 &&
strcmp(ctx->lsm_name, "default") != 0) {
pr_warning("c/r: RESTART_KEEP_LSM unsupported for %s\n",
ctx->lsm_name);
diff --git a/kernel/cred.c b/kernel/cred.c
index 06bc676..5eb09b8 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -732,6 +732,8 @@ static int do_checkpoint_cred(struct ckpt_ctx *ctx, struct cred *cred)
if (!h)
return -ENOMEM;
+ ckpt_debug("cred uid %d fsuid %d gid %d secref %d\n", cred->uid,
+ cred->fsuid, cred->gid, sec_ref);
h->uid = cred->uid;
h->suid = cred->suid;
h->euid = cred->euid;
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 8d8b69c..4fb8b5d 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -76,6 +76,7 @@
#include <linux/selinux.h>
#include <linux/mutex.h>
#include <linux/posix-timers.h>
+#include <linux/checkpoint.h>
#include "avc.h"
#include "objsec.h"
@@ -2961,6 +2962,108 @@ static int selinux_file_permission(struct file *file, int mask)
return selinux_revalidate_file_permission(file, mask);
}
+/*
+ * for file context, we print both the fsec->sid and fsec->fown_sid
+ * as string representations, separated by ':::'
+ * We don't touch isid - if you wanted that set you shoulda set up the
+ * fs correctly.
+ */
+static inline char *selinux_file_checkpoint(void *security)
+{
+ struct file_security_struct *fsec = security;
+ char *s1 = NULL, *s2 = NULL, *sfull;
+ __u32 len1, len2, lenfull;
+ int ret;
+
+ if (fsec->sid == 0 || fsec->fown_sid == 0)
+ return ERR_PTR(-EINVAL);
+
+ ret = security_sid_to_context(fsec->sid, &s1, &len1);
+ if (ret)
+ return ERR_PTR(ret);
+ len1--;
+ ret = security_sid_to_context(fsec->fown_sid, &s2, &len2);
+ if (ret) {
+ kfree(s1);
+ return ERR_PTR(ret);
+ }
+ len2--;
+ lenfull = len1+len2+3;
+ sfull = kmalloc(lenfull+1, GFP_KERNEL);
+ if (!sfull) {
+ sfull = ERR_PTR(-ENOMEM);
+ goto out;
+ }
+ sfull[lenfull] = '\0';
+ sprintf(sfull, "%s:::%s", s1, s2);
+
+out:
+ kfree(s1);
+ kfree(s2);
+ return sfull;
+}
+
+static inline int selinux_file_restore(struct file *file, char *ctx)
+{
+ char *s1, *s2;
+ __u32 sid1 = 0, sid2 = 0;
+ int ret = -EINVAL;
+ struct file_security_struct *fsec = file->f_security;
+
+ /*
+ * Objhash made sure the string is null-terminated.
+ * We make a copy so we can mangle it.
+ */
+ s1 = kstrdup(ctx, GFP_KERNEL);
+ if (!s1)
+ return -ENOMEM;
+ s2 = strstr(s1, ":::");
+ if (!s2)
+ goto out;
+
+ *s2 = '\0';
+ s2 += 3;
+ if (*s2 == '\0')
+ goto out;
+
+ /* SECSID_NULL is not valid for file sids */
+ if (strlen(s1) == 0 || strlen(s2) == 0)
+ goto out;
+
+ ret = security_context_to_sid(s1, strlen(s1), &sid1);
+ if (ret)
+ goto out;
+ ret = security_context_to_sid(s2, strlen(s2), &sid2);
+ if (ret)
+ goto out;
+
+ if (sid1 && fsec->sid != sid1) {
+ ret = avc_has_perm(current_sid(), sid1, SECCLASS_FILE,
+ FILE__RESTORE, NULL);
+ if (ret)
+ goto out;
+ fsec->sid = sid1;
+ }
+
+#if 0
+ /* The following must wait - bc we don't yet support
+ * c/r of fowners. */
+ if (sid2 && fsec->fown_sid != sid2) {
+ ret = avc_has_perm(current_sid(), sid2, SECCLASS_FILE,
+ FILE__FOWN_RESTORE, NULL);
+ if (ret)
+ goto out;
+ fsec->fown_sid = sid2;
+ }
+#endif
+
+ ret = 0;
+
+out:
+ kfree(s1);
+ return ret;
+}
+
static int selinux_file_alloc_security(struct file *file)
{
return file_alloc_security(file);
@@ -3219,6 +3322,187 @@ static int selinux_task_create(unsigned long clone_flags)
return current_has_perm(current, PROCESS__FORK);
}
+#define NUMTASKSIDS 6
+/*
+ * for cred context, we print:
+ * osid, sid, exec_sid, create_sid, keycreate_sid, sockcreate_sid;
+ * as string representations, separated by ':::'
+ */
+static inline char *selinux_cred_checkpoint(void *security)
+{
+ struct task_security_struct *tsec = security;
+ char *stmp, *sfull = NULL;
+ __u32 slen, runlen;
+ int i, ret;
+ __u32 sids[NUMTASKSIDS] = { tsec->osid, tsec->sid, tsec->exec_sid,
+ tsec->create_sid, tsec->keycreate_sid, tsec->sockcreate_sid };
+
+ if (sids[0] == 0 || sids[1] == 0)
+ /* SECSID_NULL is not valid for osid or sid */
+ return ERR_PTR(-EINVAL);
+
+ ret = security_sid_to_context(sids[0], &sfull, &runlen);
+ if (ret)
+ return ERR_PTR(ret);
+ runlen--;
+
+ for (i = 1; i < NUMTASKSIDS; i++) {
+ if (sids[i] == 0) {
+ stmp = NULL;
+ slen = 0;
+ } else {
+ ret = security_sid_to_context(sids[i], &stmp, &slen);
+ if (ret) {
+ kfree(sfull);
+ return ERR_PTR(ret);
+ }
+ slen--;
+ }
+ /* slen + runlen + ':::' + \0 */
+ if (slen) {
+ sfull = krealloc(sfull, slen + runlen + 3 + 1, GFP_KERNEL);
+ if (!sfull) {
+ kfree(stmp);
+ return ERR_PTR(-ENOMEM);
+ }
+ }
+ sprintf(sfull+runlen, ":::%s", stmp ? stmp : "");
+ runlen += slen + 3;
+ kfree(stmp);
+ }
+
+ return sfull;
+}
+
+static inline int credrestore_nullvalid(int which)
+{
+ int valid_array[NUMTASKSIDS] = {
+ 0, /* task osid */
+ 0, /* task sid */
+ 1, /* exec sid */
+ 1, /* create sid */
+ 1, /* keycreate_sid */
+ 1, /* sockcreate_sid */
+ };
+
+ return valid_array[which];
+}
+
+static inline int selinux_cred_restore(struct file *file, struct cred *cred,
+ char *ctx)
+{
+ char *s, *s1, *s2 = NULL;
+ int ret = -EINVAL;
+ struct task_security_struct *tsec = cred->security;
+ int i;
+ __u32 sids[NUMTASKSIDS];
+ struct inode *ctx_inode = file->f_dentry->d_inode;
+ struct avc_audit_data ad;
+
+ /*
+ * objhash made sure the string is null-terminated
+ * now we want our own copy so we can chop it up with \0's
+ */
+ s = kstrdup(ctx, GFP_KERNEL);
+ if (!s)
+ return -ENOMEM;
+
+ s1 = s;
+ for (i = 0; i < NUMTASKSIDS; i++) {
+ if (i < NUMTASKSIDS-1) {
+ ret = -EINVAL;
+ s2 = strstr(s1, ":::");
+ if (!s2)
+ goto out;
+ *s2 = '\0';
+ s2 += 3;
+ }
+ if (strlen(s1) == 0) {
+ ret = -EINVAL;
+ if (credrestore_nullvalid(i))
+ sids[i] = 0;
+ else
+ goto out;
+ } else {
+ ret = security_context_to_sid(s1, strlen(s1), &sids[i]);
+ if (ret)
+ goto out;
+ }
+ s1 = s2;
+ }
+
+ /*
+ * Check that these transitions are allowed, and effect them.
+ * XXX: Do these checks suffice?
+ */
+ if (tsec->osid != sids[0]) {
+ /*
+ * Are any security decisions made based on osid?
+ * Is it worth adding a PROCESS_RESTORE_OSID permission
+ * for this?
+ */
+ tsec->osid = sids[0];
+ }
+
+ if (tsec->sid != sids[1]) {
+ struct inode_security_struct *isec;
+ ret = avc_has_perm(current_sid(), sids[1], SECCLASS_PROCESS,
+ PROCESS__RESTORE, NULL);
+ if (ret)
+ goto out;
+ /* check whether checkpoint file type is a valid entry
+ * point to the new domain: we may want a specific
+ * 'restore_entrypoint' permission for this, but let's
+ * see if just entrypoint is deemed sufficient
+ */
+
+ AVC_AUDIT_DATA_INIT(&ad, FS);
+ ad.u.fs.path = file->f_path;
+
+ isec = ctx_inode->i_security;
+ ret = avc_has_perm(sids[1], isec->sid, SECCLASS_FILE,
+ FILE__ENTRYPOINT, &ad);
+ if (ret)
+ goto out;
+ /* TODO: do we need to check for shared state? */
+ tsec->sid = sids[1];
+ }
+
+ ret = -EPERM;
+ if (sids[2] != tsec->exec_sid) {
+ if (!current_has_perm(current, PROCESS__SETEXEC))
+ goto out;
+ tsec->exec_sid = sids[2];
+ }
+
+ if (sids[3] != tsec->create_sid) {
+ if (!current_has_perm(current, PROCESS__SETFSCREATE))
+ goto out;
+ tsec->create_sid = sids[3];
+ }
+
+ if (tsec->keycreate_sid != sids[4]) {
+ if (!current_has_perm(current, PROCESS__SETKEYCREATE))
+ goto out;
+ if (!may_create_key(sids[4], current))
+ goto out;
+ tsec->keycreate_sid = sids[4];
+ }
+
+ if (tsec->sockcreate_sid != sids[5]) {
+ if (!current_has_perm(current, PROCESS__SETSOCKCREATE))
+ goto out;
+ tsec->sockcreate_sid = sids[5];
+ }
+
+ ret = 0;
+
+out:
+ kfree(s);
+ return ret;
+}
+
+
/*
* detach and free the LSM part of a set of credentials
*/
@@ -4658,6 +4942,44 @@ static void ipc_free_security(struct kern_ipc_perm *perm)
kfree(isec);
}
+static inline char *selinux_msg_msg_checkpoint(void *security)
+{
+ struct msg_security_struct *msec = security;
+ char *s;
+ __u32 len;
+ int ret;
+
+ if (msec->sid == 0)
+ return ERR_PTR(-EINVAL);
+
+ ret = security_sid_to_context(msec->sid, &s, &len);
+ if (ret)
+ return ERR_PTR(ret);
+ return s;
+}
+
+static inline int selinux_msg_msg_restore(struct msg_msg *msg, char *ctx)
+{
+ struct msg_security_struct *msec = msg->security;
+ int ret;
+ __u32 sid = 0;
+
+ ret = security_context_to_sid(ctx, strlen(ctx), &sid);
+ if (ret)
+ return ret;
+
+ if (msec->sid == sid)
+ return 0;
+
+ ret = avc_has_perm(current_sid(), sid, SECCLASS_MSG,
+ MSG__RESTORE, NULL);
+ if (ret)
+ return ret;
+
+ msec->sid = sid;
+ return 0;
+}
+
static int msg_msg_alloc_security(struct msg_msg *msg)
{
struct msg_security_struct *msec;
@@ -5061,6 +5383,47 @@ static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
*secid = isec->sid;
}
+static inline char *selinux_ipc_checkpoint(void *security)
+{
+ struct ipc_security_struct *isec = security;
+ char *s;
+ __u32 len;
+ int ret;
+
+ if (isec->sid == 0)
+ return ERR_PTR(-EINVAL);
+
+ ret = security_sid_to_context(isec->sid, &s, &len);
+ if (ret)
+ return ERR_PTR(ret);
+ return s;
+}
+
+static inline int selinux_ipc_restore(struct kern_ipc_perm *ipcp, char *ctx)
+{
+ struct ipc_security_struct *isec = ipcp->security;
+ int ret;
+ __u32 sid = 0;
+ struct avc_audit_data ad;
+
+ ret = security_context_to_sid(ctx, strlen(ctx), &sid);
+ if (ret)
+ return ret;
+
+ if (isec->sid == sid)
+ return 0;
+
+ AVC_AUDIT_DATA_INIT(&ad, IPC);
+ ad.u.ipc_id = ipcp->key;
+ ret = avc_has_perm(current_sid(), sid, SECCLASS_IPC,
+ IPC__RESTORE, &ad);
+ if (ret)
+ return ret;
+
+ isec->sid = sid;
+ return 0;
+}
+
static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
{
if (inode)
@@ -5382,6 +5745,8 @@ static struct security_operations selinux_ops = {
.inode_getsecid = selinux_inode_getsecid,
.file_permission = selinux_file_permission,
+ .file_checkpoint = selinux_file_checkpoint,
+ .file_restore = selinux_file_restore,
.file_alloc_security = selinux_file_alloc_security,
.file_free_security = selinux_file_free_security,
.file_ioctl = selinux_file_ioctl,
@@ -5396,6 +5761,8 @@ static struct security_operations selinux_ops = {
.dentry_open = selinux_dentry_open,
.task_create = selinux_task_create,
+ .cred_checkpoint = selinux_cred_checkpoint,
+ .cred_restore = selinux_cred_restore,
.cred_free = selinux_cred_free,
.cred_prepare = selinux_cred_prepare,
.kernel_act_as = selinux_kernel_act_as,
@@ -5417,8 +5784,12 @@ static struct security_operations selinux_ops = {
.ipc_permission = selinux_ipc_permission,
.ipc_getsecid = selinux_ipc_getsecid,
+ .ipc_checkpoint = selinux_ipc_checkpoint,
+ .ipc_restore = selinux_ipc_restore,
.msg_msg_alloc_security = selinux_msg_msg_alloc_security,
+ .msg_msg_checkpoint = selinux_msg_msg_checkpoint,
+ .msg_msg_restore = selinux_msg_msg_restore,
.msg_msg_free_security = selinux_msg_msg_free_security,
.msg_queue_alloc_security = selinux_msg_queue_alloc_security,
diff --git a/security/selinux/include/av_perm_to_string.h b/security/selinux/include/av_perm_to_string.h
index 31df1d7..78945e7 100644
--- a/security/selinux/include/av_perm_to_string.h
+++ b/security/selinux/include/av_perm_to_string.h
@@ -19,6 +19,7 @@
S_(SECCLASS_FILE, FILE__ENTRYPOINT, "entrypoint")
S_(SECCLASS_FILE, FILE__EXECMOD, "execmod")
S_(SECCLASS_FILE, FILE__OPEN, "open")
+ S_(SECCLASS_FILE, FILE__RESTORE, "restore")
S_(SECCLASS_CHR_FILE, CHR_FILE__EXECUTE_NO_TRANS, "execute_no_trans")
S_(SECCLASS_CHR_FILE, CHR_FILE__ENTRYPOINT, "entrypoint")
S_(SECCLASS_CHR_FILE, CHR_FILE__EXECMOD, "execmod")
@@ -88,9 +89,11 @@
S_(SECCLASS_PROCESS, PROCESS__EXECHEAP, "execheap")
S_(SECCLASS_PROCESS, PROCESS__SETKEYCREATE, "setkeycreate")
S_(SECCLASS_PROCESS, PROCESS__SETSOCKCREATE, "setsockcreate")
+ S_(SECCLASS_PROCESS, PROCESS__RESTORE, "restore")
S_(SECCLASS_MSGQ, MSGQ__ENQUEUE, "enqueue")
S_(SECCLASS_MSG, MSG__SEND, "send")
S_(SECCLASS_MSG, MSG__RECEIVE, "receive")
+ S_(SECCLASS_MSG, MSG__RESTORE, "restore")
S_(SECCLASS_SHM, SHM__LOCK, "lock")
S_(SECCLASS_SECURITY, SECURITY__COMPUTE_AV, "compute_av")
S_(SECCLASS_SECURITY, SECURITY__COMPUTE_CREATE, "compute_create")
@@ -107,6 +110,7 @@
S_(SECCLASS_SYSTEM, SYSTEM__SYSLOG_READ, "syslog_read")
S_(SECCLASS_SYSTEM, SYSTEM__SYSLOG_MOD, "syslog_mod")
S_(SECCLASS_SYSTEM, SYSTEM__SYSLOG_CONSOLE, "syslog_console")
+ S_(SECCLASS_IPC, IPC__RESTORE, "restore")
S_(SECCLASS_CAPABILITY, CAPABILITY__CHOWN, "chown")
S_(SECCLASS_CAPABILITY, CAPABILITY__DAC_OVERRIDE, "dac_override")
S_(SECCLASS_CAPABILITY, CAPABILITY__DAC_READ_SEARCH, "dac_read_search")
diff --git a/security/selinux/include/av_permissions.h b/security/selinux/include/av_permissions.h
index d645192..8e066ac 100644
--- a/security/selinux/include/av_permissions.h
+++ b/security/selinux/include/av_permissions.h
@@ -101,6 +101,7 @@
#define FILE__ENTRYPOINT 0x00040000UL
#define FILE__EXECMOD 0x00080000UL
#define FILE__OPEN 0x00100000UL
+#define FILE__RESTORE 0x00200000UL
#define LNK_FILE__IOCTL 0x00000001UL
#define LNK_FILE__READ 0x00000002UL
#define LNK_FILE__WRITE 0x00000004UL
@@ -453,6 +454,7 @@
#define PROCESS__EXECHEAP 0x08000000UL
#define PROCESS__SETKEYCREATE 0x10000000UL
#define PROCESS__SETSOCKCREATE 0x20000000UL
+#define PROCESS__RESTORE 0x40000000UL
#define IPC__CREATE 0x00000001UL
#define IPC__DESTROY 0x00000002UL
#define IPC__GETATTR 0x00000004UL
@@ -462,6 +464,7 @@
#define IPC__ASSOCIATE 0x00000040UL
#define IPC__UNIX_READ 0x00000080UL
#define IPC__UNIX_WRITE 0x00000100UL
+#define IPC__RESTORE 0x00000200UL
#define SEM__CREATE 0x00000001UL
#define SEM__DESTROY 0x00000002UL
#define SEM__GETATTR 0x00000004UL
@@ -483,6 +486,7 @@
#define MSGQ__ENQUEUE 0x00000200UL
#define MSG__SEND 0x00000001UL
#define MSG__RECEIVE 0x00000002UL
+#define MSG__RESTORE 0x00000004UL
#define SHM__CREATE 0x00000001UL
#define SHM__DESTROY 0x00000002UL
#define SHM__GETATTR 0x00000004UL
--
1.6.1
--
This message was distributed to subscribers of the selinux mailing list.
If you no longer wish to subscribe, send mail to majordomo@tycho.nsa.gov with
the words "unsubscribe selinux" without quotes as the message.
^ permalink raw reply related [flat|nested] 22+ messages in thread
* Re: [PATCH 3/3] cr: add selinux support (v4)
2009-10-02 3:52 ` Serge E. Hallyn
@ 2009-10-02 12:59 ` Stephen Smalley
-1 siblings, 0 replies; 22+ messages in thread
From: Stephen Smalley @ 2009-10-02 12:59 UTC (permalink / raw)
To: Serge E. Hallyn; +Cc: Linux Containers, linux-security-module, SELinux
On Thu, 2009-10-01 at 22:52 -0500, Serge E. Hallyn wrote:
> Documentation/checkpoint/readme.txt begins:
> """
> Application checkpoint/restart is the ability to save the state
> of a running application so that it can later resume its execution
> from the time at which it was checkpointed.
> """
>
> This patch adds the ability to checkpoint and restore selinux
> contexts for tasks, open files, and sysvipc objects. Contexts
> are checkpointed as strings. For tasks and files, where a security
> struct actually points to several contexts, all contexts are
> written out in one string, separated by ':::'.
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index 8d8b69c..4fb8b5d 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -2961,6 +2962,108 @@ static int selinux_file_permission(struct file *file, int mask)
> return selinux_revalidate_file_permission(file, mask);
> }
>
> +/*
> + * for file context, we print both the fsec->sid and fsec->fown_sid
> + * as string representations, separated by ':::'
> + * We don't touch isid - if you wanted that set you shoulda set up the
> + * fs correctly.
> + */
> +static inline char *selinux_file_checkpoint(void *security)
Why are these functions declared inline? In any event, just let the
compiler figure out when to make them inline if appropriate.
> +static inline int selinux_file_restore(struct file *file, char *ctx)
> +{
> + char *s1, *s2;
> + __u32 sid1 = 0, sid2 = 0;
> + int ret = -EINVAL;
> + struct file_security_struct *fsec = file->f_security;
> +
> + /*
> + * Objhash made sure the string is null-terminated.
> + * We make a copy so we can mangle it.
> + */
> + s1 = kstrdup(ctx, GFP_KERNEL);
> + if (!s1)
> + return -ENOMEM;
> + s2 = strstr(s1, ":::");
> + if (!s2)
> + goto out;
> +
> + *s2 = '\0';
> + s2 += 3;
> + if (*s2 == '\0')
> + goto out;
> +
> + /* SECSID_NULL is not valid for file sids */
> + if (strlen(s1) == 0 || strlen(s2) == 0)
> + goto out;
> +
> + ret = security_context_to_sid(s1, strlen(s1), &sid1);
> + if (ret)
> + goto out;
> + ret = security_context_to_sid(s2, strlen(s2), &sid2);
> + if (ret)
> + goto out;
> +
> + if (sid1 && fsec->sid != sid1) {
> + ret = avc_has_perm(current_sid(), sid1, SECCLASS_FILE,
> + FILE__RESTORE, NULL);
> + if (ret)
> + goto out;
> + fsec->sid = sid1;
> + }
> +
> +#if 0
> + /* The following must wait - bc we don't yet support
> + * c/r of fowners. */
> + if (sid2 && fsec->fown_sid != sid2) {
> + ret = avc_has_perm(current_sid(), sid2, SECCLASS_FILE,
> + FILE__FOWN_RESTORE, NULL);
> + if (ret)
> + goto out;
> + fsec->fown_sid = sid2;
> + }
> +#endif
I'm not sure why you can't enable this code yet. From your comment, it
sounds like c/r doesn't yet handle the uid/euid in the fown_struct, but
that doesn't mean you can't manage the fown_sid that we store in the
file. We just leveraged the fact that a fown_struct is never outside
the context of a containing struct file (at least from a send_sigio
context) to avoid introducing a separate security field with its own
lifecycle there.
> @@ -3219,6 +3322,187 @@ static int selinux_task_create(unsigned long clone_flags)
> return current_has_perm(current, PROCESS__FORK);
> }
>
> +#define NUMTASKSIDS 6
> +/*
> + * for cred context, we print:
> + * osid, sid, exec_sid, create_sid, keycreate_sid, sockcreate_sid;
> + * as string representations, separated by ':::'
> + */
> +static inline char *selinux_cred_checkpoint(void *security)
> +{
> + struct task_security_struct *tsec = security;
> + char *stmp, *sfull = NULL;
> + __u32 slen, runlen;
> + int i, ret;
> + __u32 sids[NUMTASKSIDS] = { tsec->osid, tsec->sid, tsec->exec_sid,
> + tsec->create_sid, tsec->keycreate_sid, tsec->sockcreate_sid };
Why are you using __u32 rather than just u32? I think the former is
only necessary in certain headers that might be shared with userspace?
> +static inline int selinux_cred_restore(struct file *file, struct cred *cred,
> + char *ctx)
> +{
> + char *s, *s1, *s2 = NULL;
> + int ret = -EINVAL;
> + struct task_security_struct *tsec = cred->security;
> + int i;
> + __u32 sids[NUMTASKSIDS];
> + struct inode *ctx_inode = file->f_dentry->d_inode;
> + struct avc_audit_data ad;
audit code was refactored in mainline to share common data structures
and code among security modules, so e.g. this became common_audit_data.
Not sure what your baseline is, but this happened in July.
> + /*
> + * Check that these transitions are allowed, and effect them.
> + * XXX: Do these checks suffice?
> + */
> + if (tsec->osid != sids[0]) {
> + /*
> + * Are any security decisions made based on osid?
> + * Is it worth adding a PROCESS_RESTORE_OSID permission
> + * for this?
> + */
> + tsec->osid = sids[0];
osid is only used in kernel permission checks upon a SID transition, and
then it has been updated to ->sid prior to the transition. Userspace
however may use it in a permission check (obtained via getprevcon) on
the caller when the program runs in its own domain, e.g. passwd(1). I
suppose there should be a check for it, although possibly it could be
the same as for the ->sid (i.e. PROCESS__RESTORE).
> diff --git a/security/selinux/include/av_perm_to_string.h b/security/selinux/include/av_perm_to_string.h
> index 31df1d7..78945e7 100644
> --- a/security/selinux/include/av_perm_to_string.h
> +++ b/security/selinux/include/av_perm_to_string.h
<snip>
Just FYI, this file goes away with the dynamic class/perm discovery
patch that I've been posting to selinux list.
> diff --git a/security/selinux/include/av_permissions.h b/security/selinux/include/av_permissions.h
> index d645192..8e066ac 100644
> --- a/security/selinux/include/av_permissions.h
> +++ b/security/selinux/include/av_permissions.h
<snip>
Likewise, this file goes away and is replaced by an automatically
generated one from the new classmap.h file, which is the only kernel
file you'll need to modify to add new permissions.
--
Stephen Smalley
National Security Agency
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH 3/3] cr: add selinux support (v4)
@ 2009-10-02 12:59 ` Stephen Smalley
0 siblings, 0 replies; 22+ messages in thread
From: Stephen Smalley @ 2009-10-02 12:59 UTC (permalink / raw)
To: Serge E. Hallyn; +Cc: Linux Containers, linux-security-module, SELinux
On Thu, 2009-10-01 at 22:52 -0500, Serge E. Hallyn wrote:
> Documentation/checkpoint/readme.txt begins:
> """
> Application checkpoint/restart is the ability to save the state
> of a running application so that it can later resume its execution
> from the time at which it was checkpointed.
> """
>
> This patch adds the ability to checkpoint and restore selinux
> contexts for tasks, open files, and sysvipc objects. Contexts
> are checkpointed as strings. For tasks and files, where a security
> struct actually points to several contexts, all contexts are
> written out in one string, separated by ':::'.
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index 8d8b69c..4fb8b5d 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -2961,6 +2962,108 @@ static int selinux_file_permission(struct file *file, int mask)
> return selinux_revalidate_file_permission(file, mask);
> }
>
> +/*
> + * for file context, we print both the fsec->sid and fsec->fown_sid
> + * as string representations, separated by ':::'
> + * We don't touch isid - if you wanted that set you shoulda set up the
> + * fs correctly.
> + */
> +static inline char *selinux_file_checkpoint(void *security)
Why are these functions declared inline? In any event, just let the
compiler figure out when to make them inline if appropriate.
> +static inline int selinux_file_restore(struct file *file, char *ctx)
> +{
> + char *s1, *s2;
> + __u32 sid1 = 0, sid2 = 0;
> + int ret = -EINVAL;
> + struct file_security_struct *fsec = file->f_security;
> +
> + /*
> + * Objhash made sure the string is null-terminated.
> + * We make a copy so we can mangle it.
> + */
> + s1 = kstrdup(ctx, GFP_KERNEL);
> + if (!s1)
> + return -ENOMEM;
> + s2 = strstr(s1, ":::");
> + if (!s2)
> + goto out;
> +
> + *s2 = '\0';
> + s2 += 3;
> + if (*s2 == '\0')
> + goto out;
> +
> + /* SECSID_NULL is not valid for file sids */
> + if (strlen(s1) == 0 || strlen(s2) == 0)
> + goto out;
> +
> + ret = security_context_to_sid(s1, strlen(s1), &sid1);
> + if (ret)
> + goto out;
> + ret = security_context_to_sid(s2, strlen(s2), &sid2);
> + if (ret)
> + goto out;
> +
> + if (sid1 && fsec->sid != sid1) {
> + ret = avc_has_perm(current_sid(), sid1, SECCLASS_FILE,
> + FILE__RESTORE, NULL);
> + if (ret)
> + goto out;
> + fsec->sid = sid1;
> + }
> +
> +#if 0
> + /* The following must wait - bc we don't yet support
> + * c/r of fowners. */
> + if (sid2 && fsec->fown_sid != sid2) {
> + ret = avc_has_perm(current_sid(), sid2, SECCLASS_FILE,
> + FILE__FOWN_RESTORE, NULL);
> + if (ret)
> + goto out;
> + fsec->fown_sid = sid2;
> + }
> +#endif
I'm not sure why you can't enable this code yet. From your comment, it
sounds like c/r doesn't yet handle the uid/euid in the fown_struct, but
that doesn't mean you can't manage the fown_sid that we store in the
file. We just leveraged the fact that a fown_struct is never outside
the context of a containing struct file (at least from a send_sigio
context) to avoid introducing a separate security field with its own
lifecycle there.
> @@ -3219,6 +3322,187 @@ static int selinux_task_create(unsigned long clone_flags)
> return current_has_perm(current, PROCESS__FORK);
> }
>
> +#define NUMTASKSIDS 6
> +/*
> + * for cred context, we print:
> + * osid, sid, exec_sid, create_sid, keycreate_sid, sockcreate_sid;
> + * as string representations, separated by ':::'
> + */
> +static inline char *selinux_cred_checkpoint(void *security)
> +{
> + struct task_security_struct *tsec = security;
> + char *stmp, *sfull = NULL;
> + __u32 slen, runlen;
> + int i, ret;
> + __u32 sids[NUMTASKSIDS] = { tsec->osid, tsec->sid, tsec->exec_sid,
> + tsec->create_sid, tsec->keycreate_sid, tsec->sockcreate_sid };
Why are you using __u32 rather than just u32? I think the former is
only necessary in certain headers that might be shared with userspace?
> +static inline int selinux_cred_restore(struct file *file, struct cred *cred,
> + char *ctx)
> +{
> + char *s, *s1, *s2 = NULL;
> + int ret = -EINVAL;
> + struct task_security_struct *tsec = cred->security;
> + int i;
> + __u32 sids[NUMTASKSIDS];
> + struct inode *ctx_inode = file->f_dentry->d_inode;
> + struct avc_audit_data ad;
audit code was refactored in mainline to share common data structures
and code among security modules, so e.g. this became common_audit_data.
Not sure what your baseline is, but this happened in July.
> + /*
> + * Check that these transitions are allowed, and effect them.
> + * XXX: Do these checks suffice?
> + */
> + if (tsec->osid != sids[0]) {
> + /*
> + * Are any security decisions made based on osid?
> + * Is it worth adding a PROCESS_RESTORE_OSID permission
> + * for this?
> + */
> + tsec->osid = sids[0];
osid is only used in kernel permission checks upon a SID transition, and
then it has been updated to ->sid prior to the transition. Userspace
however may use it in a permission check (obtained via getprevcon) on
the caller when the program runs in its own domain, e.g. passwd(1). I
suppose there should be a check for it, although possibly it could be
the same as for the ->sid (i.e. PROCESS__RESTORE).
> diff --git a/security/selinux/include/av_perm_to_string.h b/security/selinux/include/av_perm_to_string.h
> index 31df1d7..78945e7 100644
> --- a/security/selinux/include/av_perm_to_string.h
> +++ b/security/selinux/include/av_perm_to_string.h
<snip>
Just FYI, this file goes away with the dynamic class/perm discovery
patch that I've been posting to selinux list.
> diff --git a/security/selinux/include/av_permissions.h b/security/selinux/include/av_permissions.h
> index d645192..8e066ac 100644
> --- a/security/selinux/include/av_permissions.h
> +++ b/security/selinux/include/av_permissions.h
<snip>
Likewise, this file goes away and is replaced by an automatically
generated one from the new classmap.h file, which is the only kernel
file you'll need to modify to add new permissions.
--
Stephen Smalley
National Security Agency
--
This message was distributed to subscribers of the selinux mailing list.
If you no longer wish to subscribe, send mail to majordomo@tycho.nsa.gov with
the words "unsubscribe selinux" without quotes as the message.
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH 1/3] cr: add generic LSM c/r support (v4)
[not found] ` <20091002034916.GA16871-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
2009-10-02 3:51 ` [PATCH 1/1] restart: accept the lsm_name field in header and add -k flag Serge E. Hallyn
@ 2009-10-02 20:57 ` Oren Laadan
2009-10-02 22:13 ` Serge E. Hallyn
1 sibling, 1 reply; 22+ messages in thread
From: Oren Laadan @ 2009-10-02 20:57 UTC (permalink / raw)
To: Serge E. Hallyn
Cc: Linux Containers, Casey Schaufler,
linux-security-module-u79uwXL29TY76Z2rM5mHXA, SELinux,
Stephen Smalley
Serge E. Hallyn wrote:
> (wasn't versioning the patchsets before, so randomly pick 4 as
> the version for this patchset...)
>
> Documentation/checkpoint/readme.txt begins:
> """
> Application checkpoint/restart is the ability to save the state
> of a running application so that it can later resume its execution
> from the time at which it was checkpointed.
> """
>
[...]
> Kernel interfaces
> =================
> diff --git a/checkpoint/checkpoint.c b/checkpoint/checkpoint.c
> index 1eeb557..6722035 100644
> --- a/checkpoint/checkpoint.c
> +++ b/checkpoint/checkpoint.c
> @@ -25,6 +25,7 @@
> #include <linux/magic.h>
> #include <linux/hrtimer.h>
> #include <linux/deferqueue.h>
> +#include <linux/security.h>
> #include <linux/checkpoint.h>
> #include <linux/checkpoint_hdr.h>
>
> @@ -351,6 +352,16 @@ static int checkpoint_write_header(struct ckpt_ctx *ctx)
> if (ret < 0)
> return ret;
>
> + memset(ctx->lsm_name, 0, SECURITY_NAME_MAX + 1);
> + strlcpy(ctx->lsm_name, security_get_lsm_name(), SECURITY_NAME_MAX + 1);
> + ret = ckpt_write_buffer(ctx, ctx->lsm_name, SECURITY_NAME_MAX + 1);
> + if (ret < 0)
> + return ret;
> +
> + ret = security_checkpoint_header(ctx);
> + if (ret < 0)
> + return ret;
> +
This is actually a case for a 'container-global' section that would
appear after the header and before the rest of the image. (Would be
useful also for network namespaces).
> return checkpoint_write_header_arch(ctx);
> }
>
> diff --git a/checkpoint/files.c b/checkpoint/files.c
> index 27e29a0..570facb 100644
> --- a/checkpoint/files.c
> +++ b/checkpoint/files.c
> @@ -145,6 +145,19 @@ static int scan_fds(struct files_struct *files, int **fdtable)
> return n;
> }
>
> +#ifdef CONFIG_SECURITY
> +int checkpoint_file_security(struct ckpt_ctx *ctx, struct file *file)
> +{
> + return security_checkpoint_obj(ctx, file->f_security,
> + CKPT_SECURITY_FILE);
> +}
> +#else
> +int checkpoint_file_security(struct ckpt_ctx *ctx, struct file *file)
> +{
> + return -EOPNOTSUPP;
> +}
> +#endif
> +
> int checkpoint_file_common(struct ckpt_ctx *ctx, struct file *file,
> struct ckpt_hdr_file *h)
> {
> @@ -159,6 +172,16 @@ int checkpoint_file_common(struct ckpt_ctx *ctx, struct file *file,
> if (h->f_credref < 0)
> return h->f_credref;
>
> + h->f_secref = checkpoint_file_security(ctx, file);
> + if (h->f_secref == -EOPNOTSUPP)
> + h->f_secref = -1;
#define CKPT_SECURITY_NONE -1 ??
> + else if (h->f_secref < 0)
> + return h->f_secref;
[...]
> +
> +static int do_checkpoint_security(struct ckpt_ctx *ctx,
> + const struct ckpt_stored_lsm *l)
> +{
> + int ret, len;
> + struct ckpt_hdr_lsm *h;
> +
> + len = strlen(l->string);
> + if (len > PAGE_SIZE - sizeof(*h))
> + return -E2BIG;
A call to ckpt_write_err() here may be useful.
> + h = ckpt_hdr_get_type(ctx, sizeof(*h)+len+1, CKPT_HDR_SEC);
> + if (!h)
> + return -ENOMEM;
> + h->len = len;
> + h->sectype = l->sectype;
> + strncpy(h->string, l->string, len);
> + h->string[len] = '\0';
> + ret = ckpt_write_obj(ctx, &h->h);
> + ckpt_hdr_put(ctx, h);
> + return ret;
> +}
> +
> +static int checkpoint_security(struct ckpt_ctx *ctx, void *ptr)
> +{
> + return do_checkpoint_security(ctx, (struct ckpt_stored_lsm *) ptr);
> +}
> +
> +static struct ckpt_stored_lsm *do_restore_security(struct ckpt_ctx *ctx)
> +{
> + struct ckpt_hdr_lsm *h;
> + struct ckpt_stored_lsm *l;
> +
> + h = ckpt_read_buf_type(ctx, PAGE_SIZE, CKPT_HDR_SEC);
> + if (IS_ERR(h))
> + return (struct ckpt_stored_lsm *)h;
> + if (h->len > h->h.len - sizeof(struct ckpt_hdr) ||
> + h->len > PAGE_SIZE) {
The second test (for h->len > PAGE_SIZE) is unnecessary - already
done in ckpt_read_buf_type()
> + ckpt_hdr_put(ctx, h);
> + return ERR_PTR(-EINVAL);
> + }
> + l = kzalloc(sizeof(*l), GFP_KERNEL);
> + if (!l) {
> + ckpt_hdr_put(ctx, h);
> + return ERR_PTR(-ENOMEM);
Nit: this part is common... set ret = -ENOMEM and use goto ?
[...]
> @@ -608,14 +613,21 @@ static int restore_task_objs(struct ckpt_ctx *ctx)
> * referenced. See comment in checkpoint_task_objs.
> */
> ret = restore_task_creds(ctx);
> - if (!ret)
> - ret = restore_task_ns(ctx);
> - if (ret < 0)
> + if (ret) {
Nit: (ret < 0) helps (me) read it.
> + ckpt_debug("restore_task_creds returned %d", ret);
> + return ret;
> + }
> + ret = restore_task_ns(ctx);
> + if (ret) {
> + ckpt_debug("restore_task_ns returned %d", ret);
> return ret;
> + }
>
> h = ckpt_read_obj_type(ctx, sizeof(*h), CKPT_HDR_TASK_OBJS);
> - if (IS_ERR(h))
> + if (IS_ERR(h)) {
> + ckpt_debug("Error fetching task obj");
> return PTR_ERR(h);
> + }
>
> ret = restore_obj_file_table(ctx, h->files_objref);
> ckpt_debug("file_table: ret %d (%p)\n", ret, current->files);
> diff --git a/checkpoint/restart.c b/checkpoint/restart.c
> index b12c8bd..bba2b45 100644
> --- a/checkpoint/restart.c
> +++ b/checkpoint/restart.c
> @@ -457,6 +457,31 @@ static int restore_read_header(struct ckpt_ctx *ctx)
> if (ret < 0)
> goto out;
>
> + ret = _ckpt_read_buffer(ctx, ctx->lsm_name, SECURITY_NAME_MAX + 1);
> + if (ret < 0)
> + goto out;
> + if (ctx->uflags & RESTART_KEEP_LSM) {
> + char *cur = security_get_lsm_name();
> + if (strncmp(cur, ctx->lsm_name, SECURITY_NAME_MAX + 1) != 0) {
> + pr_warning("c/r: checkpointed LSM %s, current is %s.\n",
> + ctx->lsm_name, cur);
> + ret = -EINVAL;
EPERM ?
[...]
> @@ -277,6 +283,16 @@ struct ckpt_hdr_groupinfo {
> __u32 groups[0];
> } __attribute__((aligned(8)));
>
> +struct ckpt_hdr_lsm {
> + struct ckpt_hdr h;
> + __u8 sectype;
> + __u16 len;
Alignment ...
> + /*
> + * This is followed by a string of size len+1,
> + * null-terminated
> + */
> + __u8 string[0];
> +} __attribute__((aligned(8)));
> /*
> * todo - keyrings and LSM
> * These may be better done with userspace help though
> @@ -392,6 +408,8 @@ struct ckpt_hdr_file {
> __s32 f_credref;
> __u64 f_pos;
> __u64 f_version;
> + __s32 f_secref;
> + __u32 f_padding;
No need for padding here.
> } __attribute__((aligned(8)));
>
> struct ckpt_hdr_file_generic {
> @@ -634,6 +652,8 @@ struct ckpt_hdr_ipc_perms {
> __u32 mode;
> __u32 _padding;
> __u64 seq;
> + __s32 sec_ref;
> + __u32 padding;
Ditto.
[...]
> @@ -224,6 +234,16 @@ static struct msg_msg *restore_msg_contents_one(struct ckpt_ctx *ctx, int *clen)
> msg->next = NULL;
> pseg = &msg->next;
>
> + if ((ctx->uflags & RESTART_KEEP_LSM) && (h->sec_ref != -1)) {
> + struct ckpt_stored_lsm *l = ckpt_obj_fetch(ctx, h->sec_ref,
> + CKPT_OBJ_SEC);
> + if (IS_ERR(l))
> + return (struct msg_msg *)l;
That's a leak. Need to 'goto out' instead.
> + ret = security_msg_msg_restore(msg, l->string);
> + if (ret)
> + return ERR_PTR(ret);
Here too.
[...]
> @@ -806,6 +815,15 @@ static struct cred *do_restore_cred(struct ckpt_ctx *ctx)
> ret = cred_setfsgid(cred, h->fsgid, &oldgid);
> if (oldgid != h->fsgid && ret < 0)
> goto err_putcred;
> + if ((ctx->uflags & RESTART_KEEP_LSM) && (h->sec_ref != -1)) {
> + struct ckpt_stored_lsm *l = ckpt_obj_fetch(ctx, h->sec_ref,
> + CKPT_OBJ_SEC);
> + if (IS_ERR(l))
> + return (struct cred *)l;
And here too ?
> +/**
> + * security_checkpoint_obj - if first checkpoint of this void* security,
> + * then 1. ask the LSM for a string representing the context, 2. checkpoint
> + * that string
> + * @ctx: the checkpoint context
> + * @security: the void* security being checkpointed
> + * @sectype: indicates the type of object, because LSMs can (and do) store
> + * different types of data for different types of objects.
> + *
> + * Returns the objref of the checkpointed ckpt_stored_lsm representing the
> + * context, or -error on error.
> + *
> + * This is only used at checkpoint of course.
> + */
> +int security_checkpoint_obj(struct ckpt_ctx *ctx, void *security,
> + unsigned sectype)
> +{
> + int strref;
> + struct ckpt_stored_lsm *l;
> + char *str;
> + int len;
> +
> + /*
> + * to simplify the LSM code, short-cut a null security
> + * here.
> + */
> + if (!security)
> + return -EOPNOTSUPP;
> +
> + switch (sectype) {
> + case CKPT_SECURITY_MSG_MSG:
> + str = security_msg_msg_checkpoint(security);
> + break;
> + case CKPT_SECURITY_IPC:
> + str = security_ipc_checkpoint(security);
> + break;
> + case CKPT_SECURITY_FILE:
> + str = security_file_checkpoint(security);
> + break;
> + case CKPT_SECURITY_CRED:
> + str = security_cred_checkpoint(security);
> + break;
> + default:
> + str = ERR_PTR(-EINVAL);
> + break;
> + }
> + /* str will be alloc'ed for us by the LSM. We will free it when
> + * we clear out our hashtable */
> + if (IS_ERR(str))
> + return PTR_ERR(str);
> +
> + len = strlen(str);
> + l = kzalloc(sizeof(*l) + len + 1, GFP_KERNEL);
Probably a dumb question: why do you allocate with the size of
the string when it merely points to the string ?
> + if (!l) {
> + kfree(str);
> + return -ENOMEM;
> + }
> + kref_init(&l->kref);
> + l->sectype = sectype;
> + l->string = str;
> +
> + strref = checkpoint_obj(ctx, l, CKPT_OBJ_SEC);
> + /* do we need to free l if strref was err? */
> + return strref;
> +}
> +
> +#endif
Oren.
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH 1/1] restart: accept the lsm_name field in header and add -k flag
[not found] ` <20091002035157.GA16920-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
@ 2009-10-02 21:02 ` Oren Laadan
0 siblings, 0 replies; 22+ messages in thread
From: Oren Laadan @ 2009-10-02 21:02 UTC (permalink / raw)
To: Serge E. Hallyn; +Cc: Linux Containers
Serge E. Hallyn wrote:
> The checkpoint file header now has an 11-character string
> containing the name of the active LSM, following the uts
> info, and a variable length buffer type conaining LSM-specific
> version information (for instance a sha1sum of policy).
> Handle these.
>
> Also add a -k (--keeplsm) flag to tell restart to set the
> RESTART_KEEP_LSM flag to sys_restart().
>
> Signed-off-by: Serge E. Hallyn <serue-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
A couple of comments below. Otherwise:
Acked-by: Oren Laadan <orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
> ---
> restart.c | 32 +++++++++++++++++++++++++++++++-
> 1 files changed, 31 insertions(+), 1 deletions(-)
>
> diff --git a/restart.c b/restart.c
> index b810ca9..44ae252 100644
> --- a/restart.c
> +++ b/restart.c
> @@ -68,6 +68,7 @@ static char usage_str[] =
> " --signal=SIG send SIG to root task on SIGINT (default: SIGKILL\n"
> " to container root, SIGINT otherwise)\n"
> " -w,--wait wait for root task to termiate (default)\n"
> +" -k,--keeplsm Try to recreate original LSM labels on all objects\n"
> " --show-status show exit status of root task (implies -w)\n"
> " --copy-status imitate exit status of root task (implies -w)\n"
> " -W,--no-wait do not wait for root task to terminate\n"
> @@ -349,6 +350,8 @@ struct args {
> char *input;
> };
>
> +int keep_lsm;
Can you please use 'struct args' for this ?
> +
> static void usage(char *str)
> {
> fprintf(stderr, "%s", str);
> @@ -377,6 +380,7 @@ static void parse_args(struct args *args, int argc, char *argv[])
> { "self", no_argument, NULL, 6},
> { "signal", required_argument, NULL, 4 },
> { "inspect", no_argument, NULL, 5 },
> + { "keeplsm", no_argument, NULL, 'k' },
> { "input", required_argument, NULL, 'i' },
> { "root", required_argument, NULL, 'r' },
> { "wait", no_argument, NULL, 'w' },
> @@ -388,7 +392,7 @@ static void parse_args(struct args *args, int argc, char *argv[])
> { "debug", no_argument, NULL, 'd' },
> { NULL, 0, NULL, 0 }
> };
> - static char optc[] = "hdvpPwWF:r:i:";
> + static char optc[] = "hdvpkPwWF:r:i:";
>
> int sig;
>
> @@ -443,6 +447,9 @@ static void parse_args(struct args *args, int argc, char *argv[])
> case 'w':
> args->wait = 1;
> break;
> + case 'k':
> + keep_lsm = RESTART_KEEP_LSM;
> + break;
> case 'W':
> args->wait = 0;
> break;
> @@ -927,6 +934,7 @@ static int ckpt_coordinator(struct ckpt_ctx *ctx)
> if (ctx->args->freezer)
> flags |= RESTART_FROZEN;
>
> + flags |= keep_lsm;
> ret = restart(root_pid, STDIN_FILENO, flags);
>
> if (ret < 0) {
> @@ -1581,6 +1589,7 @@ static int ckpt_make_tree(struct ckpt_ctx *ctx, struct task *task)
> if (task->flags & (TASK_GHOST | TASK_DEAD))
> flags |= RESTART_GHOST;
>
> + flags |= keep_lsm;
> /* on success this doesn't return */
> ckpt_dbg("about to call sys_restart(), flags %#lx\n", flags);
> ret = restart(0, STDIN_FILENO, flags);
> @@ -2057,6 +2066,7 @@ static int ckpt_read_obj_buffer(struct ckpt_ctx *ctx, void *buf, int n)
> * read/write the checkpoint image: similar to in-kernel code
> */
>
> +#define SECURITY_NAME_MAX 20
Why is this ? if it's kernel ABI then define in checkpoint_hdr.h,
or include suitable header.
> static int ckpt_read_header(struct ckpt_ctx *ctx)
> {
> struct ckpt_hdr_header *h;
> @@ -2090,6 +2100,16 @@ static int ckpt_read_header(struct ckpt_ctx *ctx)
> if (ret < 0)
> return ret;
>
> + ptr += ((struct ckpt_hdr *) ptr)->len;
> + ret = ckpt_read_obj_buffer(ctx, ptr, SECURITY_NAME_MAX + 1);
> + if (ret < 0)
> + return ret;
> +
> + ptr += ((struct ckpt_hdr *) ptr)->len;
> + ret = ckpt_read_obj_type(ctx, ptr, 200, CKPT_HDR_LSM_INFO);
> + if (ret < 0)
> + return ret;
> +
> /* FIXME: skip version validation for now */
>
> return 0;
> @@ -2169,6 +2189,16 @@ static int ckpt_write_header(struct ckpt_ctx *ctx)
> ptr += ((struct ckpt_hdr *) ptr)->len;
> ret = ckpt_write_obj(ctx, (struct ckpt_hdr *) ptr);
>
> + if (ret < 0)
> + return ret;
> + ptr += ((struct ckpt_hdr *) ptr)->len;
> + ret = ckpt_write_obj(ctx, (struct ckpt_hdr *) ptr);
> + if (ret < 0)
> + return ret;
> +
> + ptr += ((struct ckpt_hdr *) ptr)->len;
> + ret = ckpt_write_obj(ctx, (struct ckpt_hdr *) ptr);
> +
> return ret;
> }
>
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH 3/3] cr: add selinux support (v4)
2009-10-02 3:52 ` Serge E. Hallyn
(?)
(?)
@ 2009-10-02 21:14 ` Oren Laadan
2009-10-02 22:05 ` Serge E. Hallyn
-1 siblings, 1 reply; 22+ messages in thread
From: Oren Laadan @ 2009-10-02 21:14 UTC (permalink / raw)
To: Serge E. Hallyn
Cc: Linux Containers, linux-security-module, Stephen Smalley, SELinux
Serge E. Hallyn wrote:
> Documentation/checkpoint/readme.txt begins:
> """
> Application checkpoint/restart is the ability to save the state
> of a running application so that it can later resume its execution
> from the time at which it was checkpointed.
> """
>
> This patch adds the ability to checkpoint and restore selinux
> contexts for tasks, open files, and sysvipc objects. Contexts
> are checkpointed as strings. For tasks and files, where a security
> struct actually points to several contexts, all contexts are
> written out in one string, separated by ':::'.
>
> The default behaviors are to checkpoint contexts, but not to
> restore them. To attempt to restore them, sys_restart() must
> be given the RESTART_KEEP_LSM flag. If this is given then
> the caller of sys_restart() must have the new 'restore' permission
> to the target objclass, or for instance PROCESS__SETFSCREATE to
> itself to specify a create_sid.
>
> There are some tests under cr_tests/selinux at
> git://git.sr71.net/~hallyn/cr_tests.git.
>
> A corresponding simple refpolicy (and /usr/share/selinux/devel/include)
> patch is needed.
>
> The programs to checkpoint and restart (called 'checkpoint' and
> 'restart') come from git://git.ncl.cs.columbia.edu/pub/git/user-cr.git.
> This patch applies against the checkpoint/restart-enabled kernel
> tree at git://git.ncl.cs.columbia.edu/pub/git/linux-cr.git/.
>
> Changelog:
> oct 01: Remove some debugging that is redundant with
> avc log data.
> sep 10: (Most addressing suggestions by Stephen Smalley)
> 1. change xyz_get_ctx() to xyz_checkpoint().
> 2. check entrypoint permission on cred_restore
> 3. always dec context length by 1
> 4. don't allow SECSID_NULL when that's not valid
> 5. when SECSID_NULL is valid, restore it
> 6. c/r task->osid
> 7. Just print nothing instead of 'null' for SECSID_NULL
> 8. sids are __u32, as are lenghts passed to sid_to_context.
>
> Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
> Cc: Stephen Smalley <sds@epoch.ncsc.mil>
I don't know much about SElinux, so this is only for
the strict c/r code...
> ---
> checkpoint/restart.c | 1 +
> kernel/cred.c | 2 +
> security/selinux/hooks.c | 371 ++++++++++++++++++++++++++
> security/selinux/include/av_perm_to_string.h | 4 +
> security/selinux/include/av_permissions.h | 4 +
> 5 files changed, 382 insertions(+), 0 deletions(-)
>
> diff --git a/checkpoint/restart.c b/checkpoint/restart.c
> index 55bd2b5..008a116 100644
> --- a/checkpoint/restart.c
> +++ b/checkpoint/restart.c
> @@ -471,6 +471,7 @@ static int restore_read_header(struct ckpt_ctx *ctx)
> /* to be implemented later, per-lsm */
> if (strcmp(ctx->lsm_name, "lsm_none") != 0 &&
> strcmp(ctx->lsm_name, "smack") != 0 &&
> + strcmp(ctx->lsm_name, "selinux") != 0 &&
> strcmp(ctx->lsm_name, "default") != 0) {
If we expect this to grow, it may make sense to look it up in an
array.
> pr_warning("c/r: RESTART_KEEP_LSM unsupported for %s\n",
> ctx->lsm_name);
> diff --git a/kernel/cred.c b/kernel/cred.c
> index 06bc676..5eb09b8 100644
> --- a/kernel/cred.c
> +++ b/kernel/cred.c
> @@ -732,6 +732,8 @@ static int do_checkpoint_cred(struct ckpt_ctx *ctx, struct cred *cred)
> if (!h)
> return -ENOMEM;
>
> + ckpt_debug("cred uid %d fsuid %d gid %d secref %d\n", cred->uid,
> + cred->fsuid, cred->gid, sec_ref);
Please place this (and a few others also in other patches) debug-only
changes in a separate patch - it will make my life tremendously easier
when merging v18-dev to a nice and clean v19.
[...]
> +static inline char *selinux_file_checkpoint(void *security)
> +{
> + struct file_security_struct *fsec = security;
> + char *s1 = NULL, *s2 = NULL, *sfull;
> + __u32 len1, len2, lenfull;
> + int ret;
> +
> + if (fsec->sid == 0 || fsec->fown_sid == 0)
> + return ERR_PTR(-EINVAL);
> +
> + ret = security_sid_to_context(fsec->sid, &s1, &len1);
> + if (ret)
> + return ERR_PTR(ret);
> + len1--;
> + ret = security_sid_to_context(fsec->fown_sid, &s2, &len2);
> + if (ret) {
> + kfree(s1);
> + return ERR_PTR(ret);
> + }
> + len2--;
> + lenfull = len1+len2+3;
Would checkpatch.pl complain about no spaces here ?
[...]
Hmm... the rest doesn't make sense to me anyway :o
Oren.
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH 3/3] cr: add selinux support (v4)
2009-10-02 12:59 ` Stephen Smalley
@ 2009-10-02 21:55 ` Serge E. Hallyn
-1 siblings, 0 replies; 22+ messages in thread
From: Serge E. Hallyn @ 2009-10-02 21:55 UTC (permalink / raw)
To: Stephen Smalley; +Cc: Linux Containers, linux-security-module, SELinux
Quoting Stephen Smalley (sds@epoch.ncsc.mil):
> On Thu, 2009-10-01 at 22:52 -0500, Serge E. Hallyn wrote:
> > Documentation/checkpoint/readme.txt begins:
> > """
> > Application checkpoint/restart is the ability to save the state
> > of a running application so that it can later resume its execution
> > from the time at which it was checkpointed.
> > """
> >
> > This patch adds the ability to checkpoint and restore selinux
> > contexts for tasks, open files, and sysvipc objects. Contexts
> > are checkpointed as strings. For tasks and files, where a security
> > struct actually points to several contexts, all contexts are
> > written out in one string, separated by ':::'.
>
> > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> > index 8d8b69c..4fb8b5d 100644
> > --- a/security/selinux/hooks.c
> > +++ b/security/selinux/hooks.c
> > @@ -2961,6 +2962,108 @@ static int selinux_file_permission(struct file *file, int mask)
> > return selinux_revalidate_file_permission(file, mask);
> > }
> >
> > +/*
> > + * for file context, we print both the fsec->sid and fsec->fown_sid
> > + * as string representations, separated by ':::'
> > + * We don't touch isid - if you wanted that set you shoulda set up the
> > + * fs correctly.
> > + */
> > +static inline char *selinux_file_checkpoint(void *security)
Thanks for looking it over again, Stephen.
> Why are these functions declared inline? In any event, just let the
> compiler figure out when to make them inline if appropriate.
Yikes, I don't know. Must have cut-n-pasted the prototypes from
include/linux/security.h. Fixed below.
> > +static inline int selinux_file_restore(struct file *file, char *ctx)
> > +{
> > + char *s1, *s2;
> > + __u32 sid1 = 0, sid2 = 0;
> > + int ret = -EINVAL;
> > + struct file_security_struct *fsec = file->f_security;
> > +
> > + /*
> > + * Objhash made sure the string is null-terminated.
> > + * We make a copy so we can mangle it.
> > + */
> > + s1 = kstrdup(ctx, GFP_KERNEL);
> > + if (!s1)
> > + return -ENOMEM;
> > + s2 = strstr(s1, ":::");
> > + if (!s2)
> > + goto out;
> > +
> > + *s2 = '\0';
> > + s2 += 3;
> > + if (*s2 == '\0')
> > + goto out;
> > +
> > + /* SECSID_NULL is not valid for file sids */
> > + if (strlen(s1) == 0 || strlen(s2) == 0)
> > + goto out;
> > +
> > + ret = security_context_to_sid(s1, strlen(s1), &sid1);
> > + if (ret)
> > + goto out;
> > + ret = security_context_to_sid(s2, strlen(s2), &sid2);
> > + if (ret)
> > + goto out;
> > +
> > + if (sid1 && fsec->sid != sid1) {
> > + ret = avc_has_perm(current_sid(), sid1, SECCLASS_FILE,
> > + FILE__RESTORE, NULL);
> > + if (ret)
> > + goto out;
> > + fsec->sid = sid1;
> > + }
> > +
> > +#if 0
> > + /* The following must wait - bc we don't yet support
> > + * c/r of fowners. */
> > + if (sid2 && fsec->fown_sid != sid2) {
> > + ret = avc_has_perm(current_sid(), sid2, SECCLASS_FILE,
> > + FILE__FOWN_RESTORE, NULL);
> > + if (ret)
> > + goto out;
> > + fsec->fown_sid = sid2;
> > + }
> > +#endif
>
> I'm not sure why you can't enable this code yet. From your comment, it
> sounds like c/r doesn't yet handle the uid/euid in the fown_struct, but
> that doesn't mean you can't manage the fown_sid that we store in the
> file. We just leveraged the fact that a fown_struct is never outside
> the context of a containing struct file (at least from a send_sigio
> context) to avoid introducing a separate security field with its own
> lifecycle there.
Ok, I enabled it (with no resulting problems).
> > @@ -3219,6 +3322,187 @@ static int selinux_task_create(unsigned long clone_flags)
> > return current_has_perm(current, PROCESS__FORK);
> > }
> >
> > +#define NUMTASKSIDS 6
> > +/*
> > + * for cred context, we print:
> > + * osid, sid, exec_sid, create_sid, keycreate_sid, sockcreate_sid;
> > + * as string representations, separated by ':::'
> > + */
> > +static inline char *selinux_cred_checkpoint(void *security)
> > +{
> > + struct task_security_struct *tsec = security;
> > + char *stmp, *sfull = NULL;
> > + __u32 slen, runlen;
> > + int i, ret;
> > + __u32 sids[NUMTASKSIDS] = { tsec->osid, tsec->sid, tsec->exec_sid,
> > + tsec->create_sid, tsec->keycreate_sid, tsec->sockcreate_sid };
>
> Why are you using __u32 rather than just u32? I think the former is
> only necessary in certain headers that might be shared with userspace?
Changed below
> > +static inline int selinux_cred_restore(struct file *file, struct cred *cred,
> > + char *ctx)
> > +{
> > + char *s, *s1, *s2 = NULL;
> > + int ret = -EINVAL;
> > + struct task_security_struct *tsec = cred->security;
> > + int i;
> > + __u32 sids[NUMTASKSIDS];
> > + struct inode *ctx_inode = file->f_dentry->d_inode;
> > + struct avc_audit_data ad;
>
> audit code was refactored in mainline to share common data structures
> and code among security modules, so e.g. this became common_audit_data.
> Not sure what your baseline is, but this happened in July.
It was merged by Linus on Sep 11, though, which is 2 days after our
latest c/r port to his tree :)
>
> > + /*
> > + * Check that these transitions are allowed, and effect them.
> > + * XXX: Do these checks suffice?
> > + */
> > + if (tsec->osid != sids[0]) {
> > + /*
> > + * Are any security decisions made based on osid?
> > + * Is it worth adding a PROCESS_RESTORE_OSID permission
> > + * for this?
> > + */
> > + tsec->osid = sids[0];
>
> osid is only used in kernel permission checks upon a SID transition, and
> then it has been updated to ->sid prior to the transition. Userspace
> however may use it in a permission check (obtained via getprevcon) on
> the caller when the program runs in its own domain, e.g. passwd(1). I
> suppose there should be a check for it, although possibly it could be
> the same as for the ->sid (i.e. PROCESS__RESTORE).
Ok, done.
> > diff --git a/security/selinux/include/av_perm_to_string.h b/security/selinux/include/av_perm_to_string.h
> > index 31df1d7..78945e7 100644
> > --- a/security/selinux/include/av_perm_to_string.h
> > +++ b/security/selinux/include/av_perm_to_string.h
> <snip>
>
> Just FYI, this file goes away with the dynamic class/perm discovery
> patch that I've been posting to selinux list.
>
> > diff --git a/security/selinux/include/av_permissions.h b/security/selinux/include/av_permissions.h
> > index d645192..8e066ac 100644
> > --- a/security/selinux/include/av_permissions.h
> > +++ b/security/selinux/include/av_permissions.h
> <snip>
>
> Likewise, this file goes away and is replaced by an automatically
> generated one from the new classmap.h file, which is the only kernel
> file you'll need to modify to add new permissions.
Ok, that's nice actually.
So I have some work to do when we re-base to Linus' tree, but in the
meantime, here is a version addressing the rest of the comments. Or
would you prefer I wait and resend after a re-base?
thanks,
-serge
From 77a3a47895fd43e1593752a79b0b09d40744fb41 Mon Sep 17 00:00:00 2001
From: Serge E. Hallyn <serue@us.ibm.com>
Date: Thu, 27 Aug 2009 08:19:36 -0700
Subject: [PATCH 1/1] cr: add selinux support (v5)
Documentation/checkpoint/readme.txt begins:
"""
Application checkpoint/restart is the ability to save the state
of a running application so that it can later resume its execution
from the time at which it was checkpointed.
"""
This patch adds the ability to checkpoint and restore selinux
contexts for tasks, open files, and sysvipc objects. Contexts
are checkpointed as strings. For tasks and files, where a security
struct actually points to several contexts, all contexts are
written out in one string, separated by ':::'.
The default behaviors are to checkpoint contexts, but not to
restore them. To attempt to restore them, sys_restart() must
be given the RESTART_KEEP_LSM flag. If this is given then
the caller of sys_restart() must have the new 'restore' permission
to the target objclass, or for instance PROCESS__SETFSCREATE to
itself to specify a create_sid.
There are some tests under cr_tests/selinux at
git://git.sr71.net/~hallyn/cr_tests.git.
A corresponding simple refpolicy (and /usr/share/selinux/devel/include)
patch is needed.
The programs to checkpoint and restart (called 'checkpoint' and
'restart') come from git://git.ncl.cs.columbia.edu/pub/git/user-cr.git.
This patch applies against the checkpoint/restart-enabled kernel
tree at git://git.ncl.cs.columbia.edu/pub/git/linux-cr.git/.
Changelog:
oct 02: (Stephen Smalley suggestions):
1. s/__u32/u32/
2. enable the fown sid restoration
3. use process_restore to authorize resetting osid
4. don't make new hooks inline.
oct 01: Remove some debugging that is redundant with
avc log data.
sep 10: (Most addressing suggestions by Stephen Smalley)
1. change xyz_get_ctx() to xyz_checkpoint().
2. check entrypoint permission on cred_restore
3. always dec context length by 1
4. don't allow SECSID_NULL when that's not valid
5. when SECSID_NULL is valid, restore it
6. c/r task->osid
7. Just print nothing instead of 'null' for SECSID_NULL
8. sids are __u32, as are lenghts passed to sid_to_context.
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
---
checkpoint/restart.c | 1 +
kernel/cred.c | 2 +
security/selinux/hooks.c | 367 ++++++++++++++++++++++++++
security/selinux/include/av_perm_to_string.h | 5 +
security/selinux/include/av_permissions.h | 5 +
5 files changed, 380 insertions(+), 0 deletions(-)
diff --git a/checkpoint/restart.c b/checkpoint/restart.c
index 55bd2b5..008a116 100644
--- a/checkpoint/restart.c
+++ b/checkpoint/restart.c
@@ -471,6 +471,7 @@ static int restore_read_header(struct ckpt_ctx *ctx)
/* to be implemented later, per-lsm */
if (strcmp(ctx->lsm_name, "lsm_none") != 0 &&
strcmp(ctx->lsm_name, "smack") != 0 &&
+ strcmp(ctx->lsm_name, "selinux") != 0 &&
strcmp(ctx->lsm_name, "default") != 0) {
pr_warning("c/r: RESTART_KEEP_LSM unsupported for %s\n",
ctx->lsm_name);
diff --git a/kernel/cred.c b/kernel/cred.c
index 06bc676..5eb09b8 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -732,6 +732,8 @@ static int do_checkpoint_cred(struct ckpt_ctx *ctx, struct cred *cred)
if (!h)
return -ENOMEM;
+ ckpt_debug("cred uid %d fsuid %d gid %d secref %d\n", cred->uid,
+ cred->fsuid, cred->gid, sec_ref);
h->uid = cred->uid;
h->suid = cred->suid;
h->euid = cred->euid;
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 8d8b69c..7e16a56 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -76,6 +76,7 @@
#include <linux/selinux.h>
#include <linux/mutex.h>
#include <linux/posix-timers.h>
+#include <linux/checkpoint.h>
#include "avc.h"
#include "objsec.h"
@@ -2961,6 +2962,104 @@ static int selinux_file_permission(struct file *file, int mask)
return selinux_revalidate_file_permission(file, mask);
}
+/*
+ * for file context, we print both the fsec->sid and fsec->fown_sid
+ * as string representations, separated by ':::'
+ * We don't touch isid - if you wanted that set you shoulda set up the
+ * fs correctly.
+ */
+static char *selinux_file_checkpoint(void *security)
+{
+ struct file_security_struct *fsec = security;
+ char *s1 = NULL, *s2 = NULL, *sfull;
+ u32 len1, len2, lenfull;
+ int ret;
+
+ if (fsec->sid == 0 || fsec->fown_sid == 0)
+ return ERR_PTR(-EINVAL);
+
+ ret = security_sid_to_context(fsec->sid, &s1, &len1);
+ if (ret)
+ return ERR_PTR(ret);
+ len1--;
+ ret = security_sid_to_context(fsec->fown_sid, &s2, &len2);
+ if (ret) {
+ kfree(s1);
+ return ERR_PTR(ret);
+ }
+ len2--;
+ lenfull = len1+len2+3;
+ sfull = kmalloc(lenfull+1, GFP_KERNEL);
+ if (!sfull) {
+ sfull = ERR_PTR(-ENOMEM);
+ goto out;
+ }
+ sfull[lenfull] = '\0';
+ sprintf(sfull, "%s:::%s", s1, s2);
+
+out:
+ kfree(s1);
+ kfree(s2);
+ return sfull;
+}
+
+static int selinux_file_restore(struct file *file, char *ctx)
+{
+ char *s1, *s2;
+ u32 sid1 = 0, sid2 = 0;
+ int ret = -EINVAL;
+ struct file_security_struct *fsec = file->f_security;
+
+ /*
+ * Objhash made sure the string is null-terminated.
+ * We make a copy so we can mangle it.
+ */
+ s1 = kstrdup(ctx, GFP_KERNEL);
+ if (!s1)
+ return -ENOMEM;
+ s2 = strstr(s1, ":::");
+ if (!s2)
+ goto out;
+
+ *s2 = '\0';
+ s2 += 3;
+ if (*s2 == '\0')
+ goto out;
+
+ /* SECSID_NULL is not valid for file sids */
+ if (strlen(s1) == 0 || strlen(s2) == 0)
+ goto out;
+
+ ret = security_context_to_sid(s1, strlen(s1), &sid1);
+ if (ret)
+ goto out;
+ ret = security_context_to_sid(s2, strlen(s2), &sid2);
+ if (ret)
+ goto out;
+
+ if (sid1 && fsec->sid != sid1) {
+ ret = avc_has_perm(current_sid(), sid1, SECCLASS_FILE,
+ FILE__RESTORE, NULL);
+ if (ret)
+ goto out;
+ fsec->sid = sid1;
+ }
+
+ if (sid2 && fsec->fown_sid != sid2) {
+ ret = avc_has_perm(current_sid(), sid2, SECCLASS_FILE,
+ FILE__FOWN_RESTORE, NULL);
+ if (ret)
+ goto out;
+ fsec->fown_sid = sid2;
+ }
+
+ ret = 0;
+
+out:
+ kfree(s1);
+ return ret;
+}
+
static int selinux_file_alloc_security(struct file *file)
{
return file_alloc_security(file);
@@ -3219,6 +3318,187 @@ static int selinux_task_create(unsigned long clone_flags)
return current_has_perm(current, PROCESS__FORK);
}
+#define NUMTASKSIDS 6
+/*
+ * for cred context, we print:
+ * osid, sid, exec_sid, create_sid, keycreate_sid, sockcreate_sid;
+ * as string representations, separated by ':::'
+ */
+static char *selinux_cred_checkpoint(void *security)
+{
+ struct task_security_struct *tsec = security;
+ char *stmp, *sfull = NULL;
+ u32 slen, runlen;
+ int i, ret;
+ u32 sids[NUMTASKSIDS] = { tsec->osid, tsec->sid, tsec->exec_sid,
+ tsec->create_sid, tsec->keycreate_sid, tsec->sockcreate_sid };
+
+ if (sids[0] == 0 || sids[1] == 0)
+ /* SECSID_NULL is not valid for osid or sid */
+ return ERR_PTR(-EINVAL);
+
+ ret = security_sid_to_context(sids[0], &sfull, &runlen);
+ if (ret)
+ return ERR_PTR(ret);
+ runlen--;
+
+ for (i = 1; i < NUMTASKSIDS; i++) {
+ if (sids[i] == 0) {
+ stmp = NULL;
+ slen = 0;
+ } else {
+ ret = security_sid_to_context(sids[i], &stmp, &slen);
+ if (ret) {
+ kfree(sfull);
+ return ERR_PTR(ret);
+ }
+ slen--;
+ }
+ /* slen + runlen + ':::' + \0 */
+ if (slen) {
+ sfull = krealloc(sfull, slen + runlen + 3 + 1, GFP_KERNEL);
+ if (!sfull) {
+ kfree(stmp);
+ return ERR_PTR(-ENOMEM);
+ }
+ }
+ sprintf(sfull+runlen, ":::%s", stmp ? stmp : "");
+ runlen += slen + 3;
+ kfree(stmp);
+ }
+
+ return sfull;
+}
+
+static inline int credrestore_nullvalid(int which)
+{
+ int valid_array[NUMTASKSIDS] = {
+ 0, /* task osid */
+ 0, /* task sid */
+ 1, /* exec sid */
+ 1, /* create sid */
+ 1, /* keycreate_sid */
+ 1, /* sockcreate_sid */
+ };
+
+ return valid_array[which];
+}
+
+static int selinux_cred_restore(struct file *file, struct cred *cred,
+ char *ctx)
+{
+ char *s, *s1, *s2 = NULL;
+ int ret = -EINVAL;
+ struct task_security_struct *tsec = cred->security;
+ int i;
+ u32 sids[NUMTASKSIDS];
+ struct inode *ctx_inode = file->f_dentry->d_inode;
+ struct avc_audit_data ad;
+
+ /*
+ * objhash made sure the string is null-terminated
+ * now we want our own copy so we can chop it up with \0's
+ */
+ s = kstrdup(ctx, GFP_KERNEL);
+ if (!s)
+ return -ENOMEM;
+
+ s1 = s;
+ for (i = 0; i < NUMTASKSIDS; i++) {
+ if (i < NUMTASKSIDS-1) {
+ ret = -EINVAL;
+ s2 = strstr(s1, ":::");
+ if (!s2)
+ goto out;
+ *s2 = '\0';
+ s2 += 3;
+ }
+ if (strlen(s1) == 0) {
+ ret = -EINVAL;
+ if (credrestore_nullvalid(i))
+ sids[i] = 0;
+ else
+ goto out;
+ } else {
+ ret = security_context_to_sid(s1, strlen(s1), &sids[i]);
+ if (ret)
+ goto out;
+ }
+ s1 = s2;
+ }
+
+ /*
+ * Check that these transitions are allowed, and effect them.
+ * XXX: Do these checks suffice?
+ */
+ if (tsec->osid != sids[0]) {
+ ret = avc_has_perm(current_sid(), sids[0], SECCLASS_PROCESS,
+ PROCESS__RESTORE, NULL);
+ if (ret)
+ goto out;
+ tsec->osid = sids[0];
+ }
+
+ if (tsec->sid != sids[1]) {
+ struct inode_security_struct *isec;
+ ret = avc_has_perm(current_sid(), sids[1], SECCLASS_PROCESS,
+ PROCESS__RESTORE, NULL);
+ if (ret)
+ goto out;
+
+ /* check whether checkpoint file type is a valid entry
+ * point to the new domain: we may want a specific
+ * 'restore_entrypoint' permission for this, but let's
+ * see if just entrypoint is deemed sufficient
+ */
+
+ AVC_AUDIT_DATA_INIT(&ad, FS);
+ ad.u.fs.path = file->f_path;
+
+ isec = ctx_inode->i_security;
+ ret = avc_has_perm(sids[1], isec->sid, SECCLASS_FILE,
+ FILE__ENTRYPOINT, &ad);
+ if (ret)
+ goto out;
+ /* TODO: do we need to check for shared state? */
+ tsec->sid = sids[1];
+ }
+
+ ret = -EPERM;
+ if (sids[2] != tsec->exec_sid) {
+ if (!current_has_perm(current, PROCESS__SETEXEC))
+ goto out;
+ tsec->exec_sid = sids[2];
+ }
+
+ if (sids[3] != tsec->create_sid) {
+ if (!current_has_perm(current, PROCESS__SETFSCREATE))
+ goto out;
+ tsec->create_sid = sids[3];
+ }
+
+ if (tsec->keycreate_sid != sids[4]) {
+ if (!current_has_perm(current, PROCESS__SETKEYCREATE))
+ goto out;
+ if (!may_create_key(sids[4], current))
+ goto out;
+ tsec->keycreate_sid = sids[4];
+ }
+
+ if (tsec->sockcreate_sid != sids[5]) {
+ if (!current_has_perm(current, PROCESS__SETSOCKCREATE))
+ goto out;
+ tsec->sockcreate_sid = sids[5];
+ }
+
+ ret = 0;
+
+out:
+ kfree(s);
+ return ret;
+}
+
+
/*
* detach and free the LSM part of a set of credentials
*/
@@ -4658,6 +4938,44 @@ static void ipc_free_security(struct kern_ipc_perm *perm)
kfree(isec);
}
+static char *selinux_msg_msg_checkpoint(void *security)
+{
+ struct msg_security_struct *msec = security;
+ char *s;
+ u32 len;
+ int ret;
+
+ if (msec->sid == 0)
+ return ERR_PTR(-EINVAL);
+
+ ret = security_sid_to_context(msec->sid, &s, &len);
+ if (ret)
+ return ERR_PTR(ret);
+ return s;
+}
+
+static int selinux_msg_msg_restore(struct msg_msg *msg, char *ctx)
+{
+ struct msg_security_struct *msec = msg->security;
+ int ret;
+ u32 sid = 0;
+
+ ret = security_context_to_sid(ctx, strlen(ctx), &sid);
+ if (ret)
+ return ret;
+
+ if (msec->sid == sid)
+ return 0;
+
+ ret = avc_has_perm(current_sid(), sid, SECCLASS_MSG,
+ MSG__RESTORE, NULL);
+ if (ret)
+ return ret;
+
+ msec->sid = sid;
+ return 0;
+}
+
static int msg_msg_alloc_security(struct msg_msg *msg)
{
struct msg_security_struct *msec;
@@ -5061,6 +5379,47 @@ static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
*secid = isec->sid;
}
+static char *selinux_ipc_checkpoint(void *security)
+{
+ struct ipc_security_struct *isec = security;
+ char *s;
+ u32 len;
+ int ret;
+
+ if (isec->sid == 0)
+ return ERR_PTR(-EINVAL);
+
+ ret = security_sid_to_context(isec->sid, &s, &len);
+ if (ret)
+ return ERR_PTR(ret);
+ return s;
+}
+
+static int selinux_ipc_restore(struct kern_ipc_perm *ipcp, char *ctx)
+{
+ struct ipc_security_struct *isec = ipcp->security;
+ int ret;
+ u32 sid = 0;
+ struct avc_audit_data ad;
+
+ ret = security_context_to_sid(ctx, strlen(ctx), &sid);
+ if (ret)
+ return ret;
+
+ if (isec->sid == sid)
+ return 0;
+
+ AVC_AUDIT_DATA_INIT(&ad, IPC);
+ ad.u.ipc_id = ipcp->key;
+ ret = avc_has_perm(current_sid(), sid, SECCLASS_IPC,
+ IPC__RESTORE, &ad);
+ if (ret)
+ return ret;
+
+ isec->sid = sid;
+ return 0;
+}
+
static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
{
if (inode)
@@ -5382,6 +5741,8 @@ static struct security_operations selinux_ops = {
.inode_getsecid = selinux_inode_getsecid,
.file_permission = selinux_file_permission,
+ .file_checkpoint = selinux_file_checkpoint,
+ .file_restore = selinux_file_restore,
.file_alloc_security = selinux_file_alloc_security,
.file_free_security = selinux_file_free_security,
.file_ioctl = selinux_file_ioctl,
@@ -5396,6 +5757,8 @@ static struct security_operations selinux_ops = {
.dentry_open = selinux_dentry_open,
.task_create = selinux_task_create,
+ .cred_checkpoint = selinux_cred_checkpoint,
+ .cred_restore = selinux_cred_restore,
.cred_free = selinux_cred_free,
.cred_prepare = selinux_cred_prepare,
.kernel_act_as = selinux_kernel_act_as,
@@ -5417,8 +5780,12 @@ static struct security_operations selinux_ops = {
.ipc_permission = selinux_ipc_permission,
.ipc_getsecid = selinux_ipc_getsecid,
+ .ipc_checkpoint = selinux_ipc_checkpoint,
+ .ipc_restore = selinux_ipc_restore,
.msg_msg_alloc_security = selinux_msg_msg_alloc_security,
+ .msg_msg_checkpoint = selinux_msg_msg_checkpoint,
+ .msg_msg_restore = selinux_msg_msg_restore,
.msg_msg_free_security = selinux_msg_msg_free_security,
.msg_queue_alloc_security = selinux_msg_queue_alloc_security,
diff --git a/security/selinux/include/av_perm_to_string.h b/security/selinux/include/av_perm_to_string.h
index 31df1d7..a2c35d7 100644
--- a/security/selinux/include/av_perm_to_string.h
+++ b/security/selinux/include/av_perm_to_string.h
@@ -19,6 +19,8 @@
S_(SECCLASS_FILE, FILE__ENTRYPOINT, "entrypoint")
S_(SECCLASS_FILE, FILE__EXECMOD, "execmod")
S_(SECCLASS_FILE, FILE__OPEN, "open")
+ S_(SECCLASS_FILE, FILE__RESTORE, "restore")
+ S_(SECCLASS_FILE, FILE__FOWN_RESTORE, "fown_restore")
S_(SECCLASS_CHR_FILE, CHR_FILE__EXECUTE_NO_TRANS, "execute_no_trans")
S_(SECCLASS_CHR_FILE, CHR_FILE__ENTRYPOINT, "entrypoint")
S_(SECCLASS_CHR_FILE, CHR_FILE__EXECMOD, "execmod")
@@ -88,9 +90,11 @@
S_(SECCLASS_PROCESS, PROCESS__EXECHEAP, "execheap")
S_(SECCLASS_PROCESS, PROCESS__SETKEYCREATE, "setkeycreate")
S_(SECCLASS_PROCESS, PROCESS__SETSOCKCREATE, "setsockcreate")
+ S_(SECCLASS_PROCESS, PROCESS__RESTORE, "restore")
S_(SECCLASS_MSGQ, MSGQ__ENQUEUE, "enqueue")
S_(SECCLASS_MSG, MSG__SEND, "send")
S_(SECCLASS_MSG, MSG__RECEIVE, "receive")
+ S_(SECCLASS_MSG, MSG__RESTORE, "restore")
S_(SECCLASS_SHM, SHM__LOCK, "lock")
S_(SECCLASS_SECURITY, SECURITY__COMPUTE_AV, "compute_av")
S_(SECCLASS_SECURITY, SECURITY__COMPUTE_CREATE, "compute_create")
@@ -107,6 +111,7 @@
S_(SECCLASS_SYSTEM, SYSTEM__SYSLOG_READ, "syslog_read")
S_(SECCLASS_SYSTEM, SYSTEM__SYSLOG_MOD, "syslog_mod")
S_(SECCLASS_SYSTEM, SYSTEM__SYSLOG_CONSOLE, "syslog_console")
+ S_(SECCLASS_IPC, IPC__RESTORE, "restore")
S_(SECCLASS_CAPABILITY, CAPABILITY__CHOWN, "chown")
S_(SECCLASS_CAPABILITY, CAPABILITY__DAC_OVERRIDE, "dac_override")
S_(SECCLASS_CAPABILITY, CAPABILITY__DAC_READ_SEARCH, "dac_read_search")
diff --git a/security/selinux/include/av_permissions.h b/security/selinux/include/av_permissions.h
index d645192..58ad588 100644
--- a/security/selinux/include/av_permissions.h
+++ b/security/selinux/include/av_permissions.h
@@ -101,6 +101,8 @@
#define FILE__ENTRYPOINT 0x00040000UL
#define FILE__EXECMOD 0x00080000UL
#define FILE__OPEN 0x00100000UL
+#define FILE__RESTORE 0x00200000UL
+#define FILE__FOWN_RESTORE 0x00400000UL
#define LNK_FILE__IOCTL 0x00000001UL
#define LNK_FILE__READ 0x00000002UL
#define LNK_FILE__WRITE 0x00000004UL
@@ -453,6 +455,7 @@
#define PROCESS__EXECHEAP 0x08000000UL
#define PROCESS__SETKEYCREATE 0x10000000UL
#define PROCESS__SETSOCKCREATE 0x20000000UL
+#define PROCESS__RESTORE 0x40000000UL
#define IPC__CREATE 0x00000001UL
#define IPC__DESTROY 0x00000002UL
#define IPC__GETATTR 0x00000004UL
@@ -462,6 +465,7 @@
#define IPC__ASSOCIATE 0x00000040UL
#define IPC__UNIX_READ 0x00000080UL
#define IPC__UNIX_WRITE 0x00000100UL
+#define IPC__RESTORE 0x00000200UL
#define SEM__CREATE 0x00000001UL
#define SEM__DESTROY 0x00000002UL
#define SEM__GETATTR 0x00000004UL
@@ -483,6 +487,7 @@
#define MSGQ__ENQUEUE 0x00000200UL
#define MSG__SEND 0x00000001UL
#define MSG__RECEIVE 0x00000002UL
+#define MSG__RESTORE 0x00000004UL
#define SHM__CREATE 0x00000001UL
#define SHM__DESTROY 0x00000002UL
#define SHM__GETATTR 0x00000004UL
--
1.6.1
^ permalink raw reply related [flat|nested] 22+ messages in thread
* Re: [PATCH 3/3] cr: add selinux support (v4)
@ 2009-10-02 21:55 ` Serge E. Hallyn
0 siblings, 0 replies; 22+ messages in thread
From: Serge E. Hallyn @ 2009-10-02 21:55 UTC (permalink / raw)
To: Stephen Smalley; +Cc: Linux Containers, linux-security-module, SELinux
Quoting Stephen Smalley (sds@epoch.ncsc.mil):
> On Thu, 2009-10-01 at 22:52 -0500, Serge E. Hallyn wrote:
> > Documentation/checkpoint/readme.txt begins:
> > """
> > Application checkpoint/restart is the ability to save the state
> > of a running application so that it can later resume its execution
> > from the time at which it was checkpointed.
> > """
> >
> > This patch adds the ability to checkpoint and restore selinux
> > contexts for tasks, open files, and sysvipc objects. Contexts
> > are checkpointed as strings. For tasks and files, where a security
> > struct actually points to several contexts, all contexts are
> > written out in one string, separated by ':::'.
>
> > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> > index 8d8b69c..4fb8b5d 100644
> > --- a/security/selinux/hooks.c
> > +++ b/security/selinux/hooks.c
> > @@ -2961,6 +2962,108 @@ static int selinux_file_permission(struct file *file, int mask)
> > return selinux_revalidate_file_permission(file, mask);
> > }
> >
> > +/*
> > + * for file context, we print both the fsec->sid and fsec->fown_sid
> > + * as string representations, separated by ':::'
> > + * We don't touch isid - if you wanted that set you shoulda set up the
> > + * fs correctly.
> > + */
> > +static inline char *selinux_file_checkpoint(void *security)
Thanks for looking it over again, Stephen.
> Why are these functions declared inline? In any event, just let the
> compiler figure out when to make them inline if appropriate.
Yikes, I don't know. Must have cut-n-pasted the prototypes from
include/linux/security.h. Fixed below.
> > +static inline int selinux_file_restore(struct file *file, char *ctx)
> > +{
> > + char *s1, *s2;
> > + __u32 sid1 = 0, sid2 = 0;
> > + int ret = -EINVAL;
> > + struct file_security_struct *fsec = file->f_security;
> > +
> > + /*
> > + * Objhash made sure the string is null-terminated.
> > + * We make a copy so we can mangle it.
> > + */
> > + s1 = kstrdup(ctx, GFP_KERNEL);
> > + if (!s1)
> > + return -ENOMEM;
> > + s2 = strstr(s1, ":::");
> > + if (!s2)
> > + goto out;
> > +
> > + *s2 = '\0';
> > + s2 += 3;
> > + if (*s2 == '\0')
> > + goto out;
> > +
> > + /* SECSID_NULL is not valid for file sids */
> > + if (strlen(s1) == 0 || strlen(s2) == 0)
> > + goto out;
> > +
> > + ret = security_context_to_sid(s1, strlen(s1), &sid1);
> > + if (ret)
> > + goto out;
> > + ret = security_context_to_sid(s2, strlen(s2), &sid2);
> > + if (ret)
> > + goto out;
> > +
> > + if (sid1 && fsec->sid != sid1) {
> > + ret = avc_has_perm(current_sid(), sid1, SECCLASS_FILE,
> > + FILE__RESTORE, NULL);
> > + if (ret)
> > + goto out;
> > + fsec->sid = sid1;
> > + }
> > +
> > +#if 0
> > + /* The following must wait - bc we don't yet support
> > + * c/r of fowners. */
> > + if (sid2 && fsec->fown_sid != sid2) {
> > + ret = avc_has_perm(current_sid(), sid2, SECCLASS_FILE,
> > + FILE__FOWN_RESTORE, NULL);
> > + if (ret)
> > + goto out;
> > + fsec->fown_sid = sid2;
> > + }
> > +#endif
>
> I'm not sure why you can't enable this code yet. From your comment, it
> sounds like c/r doesn't yet handle the uid/euid in the fown_struct, but
> that doesn't mean you can't manage the fown_sid that we store in the
> file. We just leveraged the fact that a fown_struct is never outside
> the context of a containing struct file (at least from a send_sigio
> context) to avoid introducing a separate security field with its own
> lifecycle there.
Ok, I enabled it (with no resulting problems).
> > @@ -3219,6 +3322,187 @@ static int selinux_task_create(unsigned long clone_flags)
> > return current_has_perm(current, PROCESS__FORK);
> > }
> >
> > +#define NUMTASKSIDS 6
> > +/*
> > + * for cred context, we print:
> > + * osid, sid, exec_sid, create_sid, keycreate_sid, sockcreate_sid;
> > + * as string representations, separated by ':::'
> > + */
> > +static inline char *selinux_cred_checkpoint(void *security)
> > +{
> > + struct task_security_struct *tsec = security;
> > + char *stmp, *sfull = NULL;
> > + __u32 slen, runlen;
> > + int i, ret;
> > + __u32 sids[NUMTASKSIDS] = { tsec->osid, tsec->sid, tsec->exec_sid,
> > + tsec->create_sid, tsec->keycreate_sid, tsec->sockcreate_sid };
>
> Why are you using __u32 rather than just u32? I think the former is
> only necessary in certain headers that might be shared with userspace?
Changed below
> > +static inline int selinux_cred_restore(struct file *file, struct cred *cred,
> > + char *ctx)
> > +{
> > + char *s, *s1, *s2 = NULL;
> > + int ret = -EINVAL;
> > + struct task_security_struct *tsec = cred->security;
> > + int i;
> > + __u32 sids[NUMTASKSIDS];
> > + struct inode *ctx_inode = file->f_dentry->d_inode;
> > + struct avc_audit_data ad;
>
> audit code was refactored in mainline to share common data structures
> and code among security modules, so e.g. this became common_audit_data.
> Not sure what your baseline is, but this happened in July.
It was merged by Linus on Sep 11, though, which is 2 days after our
latest c/r port to his tree :)
>
> > + /*
> > + * Check that these transitions are allowed, and effect them.
> > + * XXX: Do these checks suffice?
> > + */
> > + if (tsec->osid != sids[0]) {
> > + /*
> > + * Are any security decisions made based on osid?
> > + * Is it worth adding a PROCESS_RESTORE_OSID permission
> > + * for this?
> > + */
> > + tsec->osid = sids[0];
>
> osid is only used in kernel permission checks upon a SID transition, and
> then it has been updated to ->sid prior to the transition. Userspace
> however may use it in a permission check (obtained via getprevcon) on
> the caller when the program runs in its own domain, e.g. passwd(1). I
> suppose there should be a check for it, although possibly it could be
> the same as for the ->sid (i.e. PROCESS__RESTORE).
Ok, done.
> > diff --git a/security/selinux/include/av_perm_to_string.h b/security/selinux/include/av_perm_to_string.h
> > index 31df1d7..78945e7 100644
> > --- a/security/selinux/include/av_perm_to_string.h
> > +++ b/security/selinux/include/av_perm_to_string.h
> <snip>
>
> Just FYI, this file goes away with the dynamic class/perm discovery
> patch that I've been posting to selinux list.
>
> > diff --git a/security/selinux/include/av_permissions.h b/security/selinux/include/av_permissions.h
> > index d645192..8e066ac 100644
> > --- a/security/selinux/include/av_permissions.h
> > +++ b/security/selinux/include/av_permissions.h
> <snip>
>
> Likewise, this file goes away and is replaced by an automatically
> generated one from the new classmap.h file, which is the only kernel
> file you'll need to modify to add new permissions.
Ok, that's nice actually.
So I have some work to do when we re-base to Linus' tree, but in the
meantime, here is a version addressing the rest of the comments. Or
would you prefer I wait and resend after a re-base?
thanks,
-serge
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH 3/3] cr: add selinux support (v4)
2009-10-02 21:14 ` Oren Laadan
@ 2009-10-02 22:05 ` Serge E. Hallyn
0 siblings, 0 replies; 22+ messages in thread
From: Serge E. Hallyn @ 2009-10-02 22:05 UTC (permalink / raw)
To: Oren Laadan
Cc: Linux Containers, linux-security-module, Stephen Smalley, SELinux
Quoting Oren Laadan (orenl@librato.com):
>
> Serge E. Hallyn wrote:
> > diff --git a/checkpoint/restart.c b/checkpoint/restart.c
> > index 55bd2b5..008a116 100644
> > --- a/checkpoint/restart.c
> > +++ b/checkpoint/restart.c
> > @@ -471,6 +471,7 @@ static int restore_read_header(struct ckpt_ctx *ctx)
> > /* to be implemented later, per-lsm */
> > if (strcmp(ctx->lsm_name, "lsm_none") != 0 &&
> > strcmp(ctx->lsm_name, "smack") != 0 &&
> > + strcmp(ctx->lsm_name, "selinux") != 0 &&
> > strcmp(ctx->lsm_name, "default") != 0) {
>
> If we expect this to grow, it may make sense to look it up in an
> array.
We don't :) The only other LSM in the kernel right now is TOMOYO.
> > pr_warning("c/r: RESTART_KEEP_LSM unsupported for %s\n",
> > ctx->lsm_name);
> > diff --git a/kernel/cred.c b/kernel/cred.c
> > index 06bc676..5eb09b8 100644
> > --- a/kernel/cred.c
> > +++ b/kernel/cred.c
> > @@ -732,6 +732,8 @@ static int do_checkpoint_cred(struct ckpt_ctx *ctx, struct cred *cred)
> > if (!h)
> > return -ENOMEM;
> >
> > + ckpt_debug("cred uid %d fsuid %d gid %d secref %d\n", cred->uid,
> > + cred->fsuid, cred->gid, sec_ref);
>
> Please place this (and a few others also in other patches) debug-only
> changes in a separate patch - it will make my life tremendously easier
> when merging v18-dev to a nice and clean v19.
Ok, I'll resend those just to containers@ to spare the lsm folks.
> [...]
>
> > +static inline char *selinux_file_checkpoint(void *security)
> > +{
> > + struct file_security_struct *fsec = security;
> > + char *s1 = NULL, *s2 = NULL, *sfull;
> > + __u32 len1, len2, lenfull;
> > + int ret;
> > +
> > + if (fsec->sid == 0 || fsec->fown_sid == 0)
> > + return ERR_PTR(-EINVAL);
> > +
> > + ret = security_sid_to_context(fsec->sid, &s1, &len1);
> > + if (ret)
> > + return ERR_PTR(ret);
> > + len1--;
> > + ret = security_sid_to_context(fsec->fown_sid, &s2, &len2);
> > + if (ret) {
> > + kfree(s1);
> > + return ERR_PTR(ret);
> > + }
> > + len2--;
> > + lenfull = len1+len2+3;
>
> Would checkpatch.pl complain about no spaces here ?
Hmm, it doesn't, actually... you'd think it should! I'll change
that in the split-up version I'll send in a bit.
thanks,
-serge
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH 3/3] cr: add selinux support (v4)
@ 2009-10-02 22:05 ` Serge E. Hallyn
0 siblings, 0 replies; 22+ messages in thread
From: Serge E. Hallyn @ 2009-10-02 22:05 UTC (permalink / raw)
To: Oren Laadan
Cc: Linux Containers, linux-security-module, Stephen Smalley, SELinux
Quoting Oren Laadan (orenl@librato.com):
>
> Serge E. Hallyn wrote:
> > diff --git a/checkpoint/restart.c b/checkpoint/restart.c
> > index 55bd2b5..008a116 100644
> > --- a/checkpoint/restart.c
> > +++ b/checkpoint/restart.c
> > @@ -471,6 +471,7 @@ static int restore_read_header(struct ckpt_ctx *ctx)
> > /* to be implemented later, per-lsm */
> > if (strcmp(ctx->lsm_name, "lsm_none") != 0 &&
> > strcmp(ctx->lsm_name, "smack") != 0 &&
> > + strcmp(ctx->lsm_name, "selinux") != 0 &&
> > strcmp(ctx->lsm_name, "default") != 0) {
>
> If we expect this to grow, it may make sense to look it up in an
> array.
We don't :) The only other LSM in the kernel right now is TOMOYO.
> > pr_warning("c/r: RESTART_KEEP_LSM unsupported for %s\n",
> > ctx->lsm_name);
> > diff --git a/kernel/cred.c b/kernel/cred.c
> > index 06bc676..5eb09b8 100644
> > --- a/kernel/cred.c
> > +++ b/kernel/cred.c
> > @@ -732,6 +732,8 @@ static int do_checkpoint_cred(struct ckpt_ctx *ctx, struct cred *cred)
> > if (!h)
> > return -ENOMEM;
> >
> > + ckpt_debug("cred uid %d fsuid %d gid %d secref %d\n", cred->uid,
> > + cred->fsuid, cred->gid, sec_ref);
>
> Please place this (and a few others also in other patches) debug-only
> changes in a separate patch - it will make my life tremendously easier
> when merging v18-dev to a nice and clean v19.
Ok, I'll resend those just to containers@ to spare the lsm folks.
> [...]
>
> > +static inline char *selinux_file_checkpoint(void *security)
> > +{
> > + struct file_security_struct *fsec = security;
> > + char *s1 = NULL, *s2 = NULL, *sfull;
> > + __u32 len1, len2, lenfull;
> > + int ret;
> > +
> > + if (fsec->sid == 0 || fsec->fown_sid == 0)
> > + return ERR_PTR(-EINVAL);
> > +
> > + ret = security_sid_to_context(fsec->sid, &s1, &len1);
> > + if (ret)
> > + return ERR_PTR(ret);
> > + len1--;
> > + ret = security_sid_to_context(fsec->fown_sid, &s2, &len2);
> > + if (ret) {
> > + kfree(s1);
> > + return ERR_PTR(ret);
> > + }
> > + len2--;
> > + lenfull = len1+len2+3;
>
> Would checkpatch.pl complain about no spaces here ?
Hmm, it doesn't, actually... you'd think it should! I'll change
that in the split-up version I'll send in a bit.
thanks,
-serge
--
This message was distributed to subscribers of the selinux mailing list.
If you no longer wish to subscribe, send mail to majordomo@tycho.nsa.gov with
the words "unsubscribe selinux" without quotes as the message.
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH 1/3] cr: add generic LSM c/r support (v4)
2009-10-02 20:57 ` [PATCH 1/3] cr: add generic LSM c/r support (v4) Oren Laadan
@ 2009-10-02 22:13 ` Serge E. Hallyn
0 siblings, 0 replies; 22+ messages in thread
From: Serge E. Hallyn @ 2009-10-02 22:13 UTC (permalink / raw)
To: Oren Laadan
Cc: Linux Containers, Casey Schaufler, linux-security-module,
Stephen Smalley, SELinux
Quoting Oren Laadan (orenl@librato.com):
>
>
> Serge E. Hallyn wrote:
> > (wasn't versioning the patchsets before, so randomly pick 4 as
> > the version for this patchset...)
> >
> > Documentation/checkpoint/readme.txt begins:
> > """
> > Application checkpoint/restart is the ability to save the state
> > of a running application so that it can later resume its execution
> > from the time at which it was checkpointed.
> > """
> >
>
> [...]
>
> > Kernel interfaces
> > =================
> > diff --git a/checkpoint/checkpoint.c b/checkpoint/checkpoint.c
> > index 1eeb557..6722035 100644
> > --- a/checkpoint/checkpoint.c
> > +++ b/checkpoint/checkpoint.c
> > @@ -25,6 +25,7 @@
> > #include <linux/magic.h>
> > #include <linux/hrtimer.h>
> > #include <linux/deferqueue.h>
> > +#include <linux/security.h>
> > #include <linux/checkpoint.h>
> > #include <linux/checkpoint_hdr.h>
> >
> > @@ -351,6 +352,16 @@ static int checkpoint_write_header(struct ckpt_ctx *ctx)
> > if (ret < 0)
> > return ret;
> >
> > + memset(ctx->lsm_name, 0, SECURITY_NAME_MAX + 1);
> > + strlcpy(ctx->lsm_name, security_get_lsm_name(), SECURITY_NAME_MAX + 1);
> > + ret = ckpt_write_buffer(ctx, ctx->lsm_name, SECURITY_NAME_MAX + 1);
> > + if (ret < 0)
> > + return ret;
> > +
> > + ret = security_checkpoint_header(ctx);
> > + if (ret < 0)
> > + return ret;
> > +
>
> This is actually a case for a 'container-global' section that would
> appear after the header and before the rest of the image. (Would be
> useful also for network namespaces).
But LSM's are specifically not containerized, so this is a host
property, not a container one.
> > return checkpoint_write_header_arch(ctx);
> > }
> >
> > diff --git a/checkpoint/files.c b/checkpoint/files.c
> > index 27e29a0..570facb 100644
> > --- a/checkpoint/files.c
> > +++ b/checkpoint/files.c
> > @@ -145,6 +145,19 @@ static int scan_fds(struct files_struct *files, int **fdtable)
> > return n;
> > }
> >
> > +#ifdef CONFIG_SECURITY
> > +int checkpoint_file_security(struct ckpt_ctx *ctx, struct file *file)
> > +{
> > + return security_checkpoint_obj(ctx, file->f_security,
> > + CKPT_SECURITY_FILE);
> > +}
> > +#else
> > +int checkpoint_file_security(struct ckpt_ctx *ctx, struct file *file)
> > +{
> > + return -EOPNOTSUPP;
> > +}
> > +#endif
> > +
> > int checkpoint_file_common(struct ckpt_ctx *ctx, struct file *file,
> > struct ckpt_hdr_file *h)
> > {
> > @@ -159,6 +172,16 @@ int checkpoint_file_common(struct ckpt_ctx *ctx, struct file *file,
> > if (h->f_credref < 0)
> > return h->f_credref;
> >
> > + h->f_secref = checkpoint_file_security(ctx, file);
> > + if (h->f_secref == -EOPNOTSUPP)
> > + h->f_secref = -1;
>
> #define CKPT_SECURITY_NONE -1 ??
Yeah, that'd be cleaner.
> > + else if (h->f_secref < 0)
> > + return h->f_secref;
>
> [...]
>
> > +
> > +static int do_checkpoint_security(struct ckpt_ctx *ctx,
> > + const struct ckpt_stored_lsm *l)
> > +{
> > + int ret, len;
> > + struct ckpt_hdr_lsm *h;
> > +
> > + len = strlen(l->string);
> > + if (len > PAGE_SIZE - sizeof(*h))
> > + return -E2BIG;
>
> A call to ckpt_write_err() here may be useful.
ok
> > + h = ckpt_hdr_get_type(ctx, sizeof(*h)+len+1, CKPT_HDR_SEC);
> > + if (!h)
> > + return -ENOMEM;
> > + h->len = len;
> > + h->sectype = l->sectype;
> > + strncpy(h->string, l->string, len);
> > + h->string[len] = '\0';
> > + ret = ckpt_write_obj(ctx, &h->h);
> > + ckpt_hdr_put(ctx, h);
> > + return ret;
> > +}
> > +
> > +static int checkpoint_security(struct ckpt_ctx *ctx, void *ptr)
> > +{
> > + return do_checkpoint_security(ctx, (struct ckpt_stored_lsm *) ptr);
> > +}
> > +
> > +static struct ckpt_stored_lsm *do_restore_security(struct ckpt_ctx *ctx)
> > +{
> > + struct ckpt_hdr_lsm *h;
> > + struct ckpt_stored_lsm *l;
> > +
> > + h = ckpt_read_buf_type(ctx, PAGE_SIZE, CKPT_HDR_SEC);
> > + if (IS_ERR(h))
> > + return (struct ckpt_stored_lsm *)h;
> > + if (h->len > h->h.len - sizeof(struct ckpt_hdr) ||
> > + h->len > PAGE_SIZE) {
>
> The second test (for h->len > PAGE_SIZE) is unnecessary - already
> done in ckpt_read_buf_type()
Huh. I had no idea :)
> > + ckpt_hdr_put(ctx, h);
> > + return ERR_PTR(-EINVAL);
> > + }
> > + l = kzalloc(sizeof(*l), GFP_KERNEL);
> > + if (!l) {
> > + ckpt_hdr_put(ctx, h);
> > + return ERR_PTR(-ENOMEM);
>
> Nit: this part is common... set ret = -ENOMEM and use goto ?
ok
> [...]
>
> > @@ -608,14 +613,21 @@ static int restore_task_objs(struct ckpt_ctx *ctx)
> > * referenced. See comment in checkpoint_task_objs.
> > */
> > ret = restore_task_creds(ctx);
> > - if (!ret)
> > - ret = restore_task_ns(ctx);
> > - if (ret < 0)
> > + if (ret) {
>
> Nit: (ret < 0) helps (me) read it.
Really? Whenever I review something like that it forces me to
go through and make sure no >0 codes will be returned for failure...
But ok.
> > + ckpt_debug("restore_task_creds returned %d", ret);
> > + return ret;
> > + }
> > + ret = restore_task_ns(ctx);
> > + if (ret) {
> > + ckpt_debug("restore_task_ns returned %d", ret);
> > return ret;
> > + }
> >
> > h = ckpt_read_obj_type(ctx, sizeof(*h), CKPT_HDR_TASK_OBJS);
> > - if (IS_ERR(h))
> > + if (IS_ERR(h)) {
> > + ckpt_debug("Error fetching task obj");
> > return PTR_ERR(h);
> > + }
> >
> > ret = restore_obj_file_table(ctx, h->files_objref);
> > ckpt_debug("file_table: ret %d (%p)\n", ret, current->files);
> > diff --git a/checkpoint/restart.c b/checkpoint/restart.c
> > index b12c8bd..bba2b45 100644
> > --- a/checkpoint/restart.c
> > +++ b/checkpoint/restart.c
> > @@ -457,6 +457,31 @@ static int restore_read_header(struct ckpt_ctx *ctx)
> > if (ret < 0)
> > goto out;
> >
> > + ret = _ckpt_read_buffer(ctx, ctx->lsm_name, SECURITY_NAME_MAX + 1);
> > + if (ret < 0)
> > + goto out;
> > + if (ctx->uflags & RESTART_KEEP_LSM) {
> > + char *cur = security_get_lsm_name();
> > + if (strncmp(cur, ctx->lsm_name, SECURITY_NAME_MAX + 1) != 0) {
> > + pr_warning("c/r: checkpointed LSM %s, current is %s.\n",
> > + ctx->lsm_name, cur);
> > + ret = -EINVAL;
>
> EPERM ?
Hmm... I think of this not as "you're not allowed" but rather "it doesn't
make sense."
> [...]
>
> > @@ -277,6 +283,16 @@ struct ckpt_hdr_groupinfo {
> > __u32 groups[0];
> > } __attribute__((aligned(8)));
> >
> > +struct ckpt_hdr_lsm {
> > + struct ckpt_hdr h;
> > + __u8 sectype;
> > + __u16 len;
>
> Alignment ...
>
> > + /*
> > + * This is followed by a string of size len+1,
> > + * null-terminated
> > + */
> > + __u8 string[0];
> > +} __attribute__((aligned(8)));
> > /*
> > * todo - keyrings and LSM
> > * These may be better done with userspace help though
> > @@ -392,6 +408,8 @@ struct ckpt_hdr_file {
> > __s32 f_credref;
> > __u64 f_pos;
> > __u64 f_version;
> > + __s32 f_secref;
> > + __u32 f_padding;
>
> No need for padding here.
>
> > } __attribute__((aligned(8)));
> >
> > struct ckpt_hdr_file_generic {
> > @@ -634,6 +652,8 @@ struct ckpt_hdr_ipc_perms {
> > __u32 mode;
> > __u32 _padding;
> > __u64 seq;
> > + __s32 sec_ref;
> > + __u32 padding;
>
> Ditto.
>
> [...]
>
> > @@ -224,6 +234,16 @@ static struct msg_msg *restore_msg_contents_one(struct ckpt_ctx *ctx, int *clen)
> > msg->next = NULL;
> > pseg = &msg->next;
> >
> > + if ((ctx->uflags & RESTART_KEEP_LSM) && (h->sec_ref != -1)) {
> > + struct ckpt_stored_lsm *l = ckpt_obj_fetch(ctx, h->sec_ref,
> > + CKPT_OBJ_SEC);
> > + if (IS_ERR(l))
> > + return (struct msg_msg *)l;
>
> That's a leak. Need to 'goto out' instead.
ok
> > + ret = security_msg_msg_restore(msg, l->string);
> > + if (ret)
> > + return ERR_PTR(ret);
>
> Here too.
>
> [...]
>
> > @@ -806,6 +815,15 @@ static struct cred *do_restore_cred(struct ckpt_ctx *ctx)
> > ret = cred_setfsgid(cred, h->fsgid, &oldgid);
> > if (oldgid != h->fsgid && ret < 0)
> > goto err_putcred;
> > + if ((ctx->uflags & RESTART_KEEP_LSM) && (h->sec_ref != -1)) {
> > + struct ckpt_stored_lsm *l = ckpt_obj_fetch(ctx, h->sec_ref,
> > + CKPT_OBJ_SEC);
> > + if (IS_ERR(l))
> > + return (struct cred *)l;
>
> And here too ?
>
> > +/**
> > + * security_checkpoint_obj - if first checkpoint of this void* security,
> > + * then 1. ask the LSM for a string representing the context, 2. checkpoint
> > + * that string
> > + * @ctx: the checkpoint context
> > + * @security: the void* security being checkpointed
> > + * @sectype: indicates the type of object, because LSMs can (and do) store
> > + * different types of data for different types of objects.
> > + *
> > + * Returns the objref of the checkpointed ckpt_stored_lsm representing the
> > + * context, or -error on error.
> > + *
> > + * This is only used at checkpoint of course.
> > + */
> > +int security_checkpoint_obj(struct ckpt_ctx *ctx, void *security,
> > + unsigned sectype)
> > +{
> > + int strref;
> > + struct ckpt_stored_lsm *l;
> > + char *str;
> > + int len;
> > +
> > + /*
> > + * to simplify the LSM code, short-cut a null security
> > + * here.
> > + */
> > + if (!security)
> > + return -EOPNOTSUPP;
> > +
> > + switch (sectype) {
> > + case CKPT_SECURITY_MSG_MSG:
> > + str = security_msg_msg_checkpoint(security);
> > + break;
> > + case CKPT_SECURITY_IPC:
> > + str = security_ipc_checkpoint(security);
> > + break;
> > + case CKPT_SECURITY_FILE:
> > + str = security_file_checkpoint(security);
> > + break;
> > + case CKPT_SECURITY_CRED:
> > + str = security_cred_checkpoint(security);
> > + break;
> > + default:
> > + str = ERR_PTR(-EINVAL);
> > + break;
> > + }
> > + /* str will be alloc'ed for us by the LSM. We will free it when
> > + * we clear out our hashtable */
> > + if (IS_ERR(str))
> > + return PTR_ERR(str);
> > +
> > + len = strlen(str);
> > + l = kzalloc(sizeof(*l) + len + 1, GFP_KERNEL);
>
> Probably a dumb question: why do you allocate with the size of
> the string when it merely points to the string ?
No just dumb code - I used to strcpy it in but don't anymore.
> > + if (!l) {
> > + kfree(str);
> > + return -ENOMEM;
> > + }
> > + kref_init(&l->kref);
> > + l->sectype = sectype;
> > + l->string = str;
> > +
> > + strref = checkpoint_obj(ctx, l, CKPT_OBJ_SEC);
> > + /* do we need to free l if strref was err? */
> > + return strref;
> > +}
> > +
> > +#endif
>
> Oren.
Thanks! Will send a new version.
-serge
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH 1/3] cr: add generic LSM c/r support (v4)
@ 2009-10-02 22:13 ` Serge E. Hallyn
0 siblings, 0 replies; 22+ messages in thread
From: Serge E. Hallyn @ 2009-10-02 22:13 UTC (permalink / raw)
To: Oren Laadan
Cc: Linux Containers, Casey Schaufler, linux-security-module,
Stephen Smalley, SELinux
Quoting Oren Laadan (orenl@librato.com):
>
>
> Serge E. Hallyn wrote:
> > (wasn't versioning the patchsets before, so randomly pick 4 as
> > the version for this patchset...)
> >
> > Documentation/checkpoint/readme.txt begins:
> > """
> > Application checkpoint/restart is the ability to save the state
> > of a running application so that it can later resume its execution
> > from the time at which it was checkpointed.
> > """
> >
>
> [...]
>
> > Kernel interfaces
> > =================
> > diff --git a/checkpoint/checkpoint.c b/checkpoint/checkpoint.c
> > index 1eeb557..6722035 100644
> > --- a/checkpoint/checkpoint.c
> > +++ b/checkpoint/checkpoint.c
> > @@ -25,6 +25,7 @@
> > #include <linux/magic.h>
> > #include <linux/hrtimer.h>
> > #include <linux/deferqueue.h>
> > +#include <linux/security.h>
> > #include <linux/checkpoint.h>
> > #include <linux/checkpoint_hdr.h>
> >
> > @@ -351,6 +352,16 @@ static int checkpoint_write_header(struct ckpt_ctx *ctx)
> > if (ret < 0)
> > return ret;
> >
> > + memset(ctx->lsm_name, 0, SECURITY_NAME_MAX + 1);
> > + strlcpy(ctx->lsm_name, security_get_lsm_name(), SECURITY_NAME_MAX + 1);
> > + ret = ckpt_write_buffer(ctx, ctx->lsm_name, SECURITY_NAME_MAX + 1);
> > + if (ret < 0)
> > + return ret;
> > +
> > + ret = security_checkpoint_header(ctx);
> > + if (ret < 0)
> > + return ret;
> > +
>
> This is actually a case for a 'container-global' section that would
> appear after the header and before the rest of the image. (Would be
> useful also for network namespaces).
But LSM's are specifically not containerized, so this is a host
property, not a container one.
> > return checkpoint_write_header_arch(ctx);
> > }
> >
> > diff --git a/checkpoint/files.c b/checkpoint/files.c
> > index 27e29a0..570facb 100644
> > --- a/checkpoint/files.c
> > +++ b/checkpoint/files.c
> > @@ -145,6 +145,19 @@ static int scan_fds(struct files_struct *files, int **fdtable)
> > return n;
> > }
> >
> > +#ifdef CONFIG_SECURITY
> > +int checkpoint_file_security(struct ckpt_ctx *ctx, struct file *file)
> > +{
> > + return security_checkpoint_obj(ctx, file->f_security,
> > + CKPT_SECURITY_FILE);
> > +}
> > +#else
> > +int checkpoint_file_security(struct ckpt_ctx *ctx, struct file *file)
> > +{
> > + return -EOPNOTSUPP;
> > +}
> > +#endif
> > +
> > int checkpoint_file_common(struct ckpt_ctx *ctx, struct file *file,
> > struct ckpt_hdr_file *h)
> > {
> > @@ -159,6 +172,16 @@ int checkpoint_file_common(struct ckpt_ctx *ctx, struct file *file,
> > if (h->f_credref < 0)
> > return h->f_credref;
> >
> > + h->f_secref = checkpoint_file_security(ctx, file);
> > + if (h->f_secref == -EOPNOTSUPP)
> > + h->f_secref = -1;
>
> #define CKPT_SECURITY_NONE -1 ??
Yeah, that'd be cleaner.
> > + else if (h->f_secref < 0)
> > + return h->f_secref;
>
> [...]
>
> > +
> > +static int do_checkpoint_security(struct ckpt_ctx *ctx,
> > + const struct ckpt_stored_lsm *l)
> > +{
> > + int ret, len;
> > + struct ckpt_hdr_lsm *h;
> > +
> > + len = strlen(l->string);
> > + if (len > PAGE_SIZE - sizeof(*h))
> > + return -E2BIG;
>
> A call to ckpt_write_err() here may be useful.
ok
> > + h = ckpt_hdr_get_type(ctx, sizeof(*h)+len+1, CKPT_HDR_SEC);
> > + if (!h)
> > + return -ENOMEM;
> > + h->len = len;
> > + h->sectype = l->sectype;
> > + strncpy(h->string, l->string, len);
> > + h->string[len] = '\0';
> > + ret = ckpt_write_obj(ctx, &h->h);
> > + ckpt_hdr_put(ctx, h);
> > + return ret;
> > +}
> > +
> > +static int checkpoint_security(struct ckpt_ctx *ctx, void *ptr)
> > +{
> > + return do_checkpoint_security(ctx, (struct ckpt_stored_lsm *) ptr);
> > +}
> > +
> > +static struct ckpt_stored_lsm *do_restore_security(struct ckpt_ctx *ctx)
> > +{
> > + struct ckpt_hdr_lsm *h;
> > + struct ckpt_stored_lsm *l;
> > +
> > + h = ckpt_read_buf_type(ctx, PAGE_SIZE, CKPT_HDR_SEC);
> > + if (IS_ERR(h))
> > + return (struct ckpt_stored_lsm *)h;
> > + if (h->len > h->h.len - sizeof(struct ckpt_hdr) ||
> > + h->len > PAGE_SIZE) {
>
> The second test (for h->len > PAGE_SIZE) is unnecessary - already
> done in ckpt_read_buf_type()
Huh. I had no idea :)
> > + ckpt_hdr_put(ctx, h);
> > + return ERR_PTR(-EINVAL);
> > + }
> > + l = kzalloc(sizeof(*l), GFP_KERNEL);
> > + if (!l) {
> > + ckpt_hdr_put(ctx, h);
> > + return ERR_PTR(-ENOMEM);
>
> Nit: this part is common... set ret = -ENOMEM and use goto ?
ok
> [...]
>
> > @@ -608,14 +613,21 @@ static int restore_task_objs(struct ckpt_ctx *ctx)
> > * referenced. See comment in checkpoint_task_objs.
> > */
> > ret = restore_task_creds(ctx);
> > - if (!ret)
> > - ret = restore_task_ns(ctx);
> > - if (ret < 0)
> > + if (ret) {
>
> Nit: (ret < 0) helps (me) read it.
Really? Whenever I review something like that it forces me to
go through and make sure no >0 codes will be returned for failure...
But ok.
> > + ckpt_debug("restore_task_creds returned %d", ret);
> > + return ret;
> > + }
> > + ret = restore_task_ns(ctx);
> > + if (ret) {
> > + ckpt_debug("restore_task_ns returned %d", ret);
> > return ret;
> > + }
> >
> > h = ckpt_read_obj_type(ctx, sizeof(*h), CKPT_HDR_TASK_OBJS);
> > - if (IS_ERR(h))
> > + if (IS_ERR(h)) {
> > + ckpt_debug("Error fetching task obj");
> > return PTR_ERR(h);
> > + }
> >
> > ret = restore_obj_file_table(ctx, h->files_objref);
> > ckpt_debug("file_table: ret %d (%p)\n", ret, current->files);
> > diff --git a/checkpoint/restart.c b/checkpoint/restart.c
> > index b12c8bd..bba2b45 100644
> > --- a/checkpoint/restart.c
> > +++ b/checkpoint/restart.c
> > @@ -457,6 +457,31 @@ static int restore_read_header(struct ckpt_ctx *ctx)
> > if (ret < 0)
> > goto out;
> >
> > + ret = _ckpt_read_buffer(ctx, ctx->lsm_name, SECURITY_NAME_MAX + 1);
> > + if (ret < 0)
> > + goto out;
> > + if (ctx->uflags & RESTART_KEEP_LSM) {
> > + char *cur = security_get_lsm_name();
> > + if (strncmp(cur, ctx->lsm_name, SECURITY_NAME_MAX + 1) != 0) {
> > + pr_warning("c/r: checkpointed LSM %s, current is %s.\n",
> > + ctx->lsm_name, cur);
> > + ret = -EINVAL;
>
> EPERM ?
Hmm... I think of this not as "you're not allowed" but rather "it doesn't
make sense."
> [...]
>
> > @@ -277,6 +283,16 @@ struct ckpt_hdr_groupinfo {
> > __u32 groups[0];
> > } __attribute__((aligned(8)));
> >
> > +struct ckpt_hdr_lsm {
> > + struct ckpt_hdr h;
> > + __u8 sectype;
> > + __u16 len;
>
> Alignment ...
>
> > + /*
> > + * This is followed by a string of size len+1,
> > + * null-terminated
> > + */
> > + __u8 string[0];
> > +} __attribute__((aligned(8)));
> > /*
> > * todo - keyrings and LSM
> > * These may be better done with userspace help though
> > @@ -392,6 +408,8 @@ struct ckpt_hdr_file {
> > __s32 f_credref;
> > __u64 f_pos;
> > __u64 f_version;
> > + __s32 f_secref;
> > + __u32 f_padding;
>
> No need for padding here.
>
> > } __attribute__((aligned(8)));
> >
> > struct ckpt_hdr_file_generic {
> > @@ -634,6 +652,8 @@ struct ckpt_hdr_ipc_perms {
> > __u32 mode;
> > __u32 _padding;
> > __u64 seq;
> > + __s32 sec_ref;
> > + __u32 padding;
>
> Ditto.
>
> [...]
>
> > @@ -224,6 +234,16 @@ static struct msg_msg *restore_msg_contents_one(struct ckpt_ctx *ctx, int *clen)
> > msg->next = NULL;
> > pseg = &msg->next;
> >
> > + if ((ctx->uflags & RESTART_KEEP_LSM) && (h->sec_ref != -1)) {
> > + struct ckpt_stored_lsm *l = ckpt_obj_fetch(ctx, h->sec_ref,
> > + CKPT_OBJ_SEC);
> > + if (IS_ERR(l))
> > + return (struct msg_msg *)l;
>
> That's a leak. Need to 'goto out' instead.
ok
> > + ret = security_msg_msg_restore(msg, l->string);
> > + if (ret)
> > + return ERR_PTR(ret);
>
> Here too.
>
> [...]
>
> > @@ -806,6 +815,15 @@ static struct cred *do_restore_cred(struct ckpt_ctx *ctx)
> > ret = cred_setfsgid(cred, h->fsgid, &oldgid);
> > if (oldgid != h->fsgid && ret < 0)
> > goto err_putcred;
> > + if ((ctx->uflags & RESTART_KEEP_LSM) && (h->sec_ref != -1)) {
> > + struct ckpt_stored_lsm *l = ckpt_obj_fetch(ctx, h->sec_ref,
> > + CKPT_OBJ_SEC);
> > + if (IS_ERR(l))
> > + return (struct cred *)l;
>
> And here too ?
>
> > +/**
> > + * security_checkpoint_obj - if first checkpoint of this void* security,
> > + * then 1. ask the LSM for a string representing the context, 2. checkpoint
> > + * that string
> > + * @ctx: the checkpoint context
> > + * @security: the void* security being checkpointed
> > + * @sectype: indicates the type of object, because LSMs can (and do) store
> > + * different types of data for different types of objects.
> > + *
> > + * Returns the objref of the checkpointed ckpt_stored_lsm representing the
> > + * context, or -error on error.
> > + *
> > + * This is only used at checkpoint of course.
> > + */
> > +int security_checkpoint_obj(struct ckpt_ctx *ctx, void *security,
> > + unsigned sectype)
> > +{
> > + int strref;
> > + struct ckpt_stored_lsm *l;
> > + char *str;
> > + int len;
> > +
> > + /*
> > + * to simplify the LSM code, short-cut a null security
> > + * here.
> > + */
> > + if (!security)
> > + return -EOPNOTSUPP;
> > +
> > + switch (sectype) {
> > + case CKPT_SECURITY_MSG_MSG:
> > + str = security_msg_msg_checkpoint(security);
> > + break;
> > + case CKPT_SECURITY_IPC:
> > + str = security_ipc_checkpoint(security);
> > + break;
> > + case CKPT_SECURITY_FILE:
> > + str = security_file_checkpoint(security);
> > + break;
> > + case CKPT_SECURITY_CRED:
> > + str = security_cred_checkpoint(security);
> > + break;
> > + default:
> > + str = ERR_PTR(-EINVAL);
> > + break;
> > + }
> > + /* str will be alloc'ed for us by the LSM. We will free it when
> > + * we clear out our hashtable */
> > + if (IS_ERR(str))
> > + return PTR_ERR(str);
> > +
> > + len = strlen(str);
> > + l = kzalloc(sizeof(*l) + len + 1, GFP_KERNEL);
>
> Probably a dumb question: why do you allocate with the size of
> the string when it merely points to the string ?
No just dumb code - I used to strcpy it in but don't anymore.
> > + if (!l) {
> > + kfree(str);
> > + return -ENOMEM;
> > + }
> > + kref_init(&l->kref);
> > + l->sectype = sectype;
> > + l->string = str;
> > +
> > + strref = checkpoint_obj(ctx, l, CKPT_OBJ_SEC);
> > + /* do we need to free l if strref was err? */
> > + return strref;
> > +}
> > +
> > +#endif
>
> Oren.
Thanks! Will send a new version.
-serge
--
This message was distributed to subscribers of the selinux mailing list.
If you no longer wish to subscribe, send mail to majordomo@tycho.nsa.gov with
the words "unsubscribe selinux" without quotes as the message.
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH 3/3] cr: add selinux support (v4)
2009-10-02 22:05 ` Serge E. Hallyn
@ 2009-10-02 22:14 ` Serge E. Hallyn
-1 siblings, 0 replies; 22+ messages in thread
From: Serge E. Hallyn @ 2009-10-02 22:14 UTC (permalink / raw)
To: Oren Laadan
Cc: Linux Containers, linux-security-module, Stephen Smalley, SELinux
Quoting Serge E. Hallyn (serue@us.ibm.com):
> Quoting Oren Laadan (orenl@librato.com):
> > Please place this (and a few others also in other patches) debug-only
> > changes in a separate patch - it will make my life tremendously easier
> > when merging v18-dev to a nice and clean v19.
>
> Ok, I'll resend those just to containers@ to spare the lsm folks.
Oops, I was thinking this was the patch 1/3. I won't spare the
lsm folks from revised patches 2/3 or 3/3 :)
-serge
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH 3/3] cr: add selinux support (v4)
@ 2009-10-02 22:14 ` Serge E. Hallyn
0 siblings, 0 replies; 22+ messages in thread
From: Serge E. Hallyn @ 2009-10-02 22:14 UTC (permalink / raw)
To: Oren Laadan
Cc: Linux Containers, linux-security-module, Stephen Smalley, SELinux
Quoting Serge E. Hallyn (serue@us.ibm.com):
> Quoting Oren Laadan (orenl@librato.com):
> > Please place this (and a few others also in other patches) debug-only
> > changes in a separate patch - it will make my life tremendously easier
> > when merging v18-dev to a nice and clean v19.
>
> Ok, I'll resend those just to containers@ to spare the lsm folks.
Oops, I was thinking this was the patch 1/3. I won't spare the
lsm folks from revised patches 2/3 or 3/3 :)
-serge
--
This message was distributed to subscribers of the selinux mailing list.
If you no longer wish to subscribe, send mail to majordomo@tycho.nsa.gov with
the words "unsubscribe selinux" without quotes as the message.
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH 1/3] cr: add generic LSM c/r support (v4)
2009-10-02 22:13 ` Serge E. Hallyn
(?)
@ 2009-10-02 22:23 ` Oren Laadan
2009-10-02 22:31 ` Serge E. Hallyn
-1 siblings, 1 reply; 22+ messages in thread
From: Oren Laadan @ 2009-10-02 22:23 UTC (permalink / raw)
To: Serge E. Hallyn
Cc: Linux Containers, Casey Schaufler, linux-security-module,
Stephen Smalley, SELinux
Serge E. Hallyn wrote:
> Quoting Oren Laadan (orenl@librato.com):
>>
>> Serge E. Hallyn wrote:
>>> (wasn't versioning the patchsets before, so randomly pick 4 as
>>> the version for this patchset...)
>>>
>>> Documentation/checkpoint/readme.txt begins:
>>> """
>>> Application checkpoint/restart is the ability to save the state
>>> of a running application so that it can later resume its execution
>>> from the time at which it was checkpointed.
>>> """
>>>
[...]
>>> + memset(ctx->lsm_name, 0, SECURITY_NAME_MAX + 1);
>>> + strlcpy(ctx->lsm_name, security_get_lsm_name(), SECURITY_NAME_MAX + 1);
>>> + ret = ckpt_write_buffer(ctx, ctx->lsm_name, SECURITY_NAME_MAX + 1);
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + ret = security_checkpoint_header(ctx);
>>> + if (ret < 0)
>>> + return ret;
>>> +
>> This is actually a case for a 'container-global' section that would
>> appear after the header and before the rest of the image. (Would be
>> useful also for network namespaces).
>
> But LSM's are specifically not containerized, so this is a host
> property, not a container one.
Hmmm... does that mean you can't apply one policy to one container
and another policy to another ?
Anyway, it belongs to a 'global' section, that may have 2 parts:
host and container. (Putting it between header and arch-header
seems weird...)
The header doesn't hold state, it is a declarative section about
the properties of the original host (kernel and HW).
Oren.
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH 1/3] cr: add generic LSM c/r support (v4)
2009-10-02 22:23 ` Oren Laadan
@ 2009-10-02 22:31 ` Serge E. Hallyn
0 siblings, 0 replies; 22+ messages in thread
From: Serge E. Hallyn @ 2009-10-02 22:31 UTC (permalink / raw)
To: Oren Laadan
Cc: Linux Containers, Casey Schaufler, linux-security-module,
Stephen Smalley, SELinux
Quoting Oren Laadan (orenl@librato.com):
>
>
> Serge E. Hallyn wrote:
> > Quoting Oren Laadan (orenl@librato.com):
> >>
> >> Serge E. Hallyn wrote:
> >>> (wasn't versioning the patchsets before, so randomly pick 4 as
> >>> the version for this patchset...)
> >>>
> >>> Documentation/checkpoint/readme.txt begins:
> >>> """
> >>> Application checkpoint/restart is the ability to save the state
> >>> of a running application so that it can later resume its execution
> >>> from the time at which it was checkpointed.
> >>> """
> >>>
>
> [...]
>
> >>> + memset(ctx->lsm_name, 0, SECURITY_NAME_MAX + 1);
> >>> + strlcpy(ctx->lsm_name, security_get_lsm_name(), SECURITY_NAME_MAX + 1);
> >>> + ret = ckpt_write_buffer(ctx, ctx->lsm_name, SECURITY_NAME_MAX + 1);
> >>> + if (ret < 0)
> >>> + return ret;
> >>> +
> >>> + ret = security_checkpoint_header(ctx);
> >>> + if (ret < 0)
> >>> + return ret;
> >>> +
> >> This is actually a case for a 'container-global' section that would
> >> appear after the header and before the rest of the image. (Would be
> >> useful also for network namespaces).
> >
> > But LSM's are specifically not containerized, so this is a host
> > property, not a container one.
>
> Hmmm... does that mean you can't apply one policy to one container
> and another policy to another ?
Yup.
> Anyway, it belongs to a 'global' section, that may have 2 parts:
> host and container. (Putting it between header and arch-header
> seems weird...)
Ok, then I'll add that in the next set.
> The header doesn't hold state, it is a declarative section about
> the properties of the original host (kernel and HW).
Ok, I see.
thanks,
-serge
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH 1/3] cr: add generic LSM c/r support (v4)
@ 2009-10-02 22:31 ` Serge E. Hallyn
0 siblings, 0 replies; 22+ messages in thread
From: Serge E. Hallyn @ 2009-10-02 22:31 UTC (permalink / raw)
To: Oren Laadan
Cc: Linux Containers, Casey Schaufler, linux-security-module,
Stephen Smalley, SELinux
Quoting Oren Laadan (orenl@librato.com):
>
>
> Serge E. Hallyn wrote:
> > Quoting Oren Laadan (orenl@librato.com):
> >>
> >> Serge E. Hallyn wrote:
> >>> (wasn't versioning the patchsets before, so randomly pick 4 as
> >>> the version for this patchset...)
> >>>
> >>> Documentation/checkpoint/readme.txt begins:
> >>> """
> >>> Application checkpoint/restart is the ability to save the state
> >>> of a running application so that it can later resume its execution
> >>> from the time at which it was checkpointed.
> >>> """
> >>>
>
> [...]
>
> >>> + memset(ctx->lsm_name, 0, SECURITY_NAME_MAX + 1);
> >>> + strlcpy(ctx->lsm_name, security_get_lsm_name(), SECURITY_NAME_MAX + 1);
> >>> + ret = ckpt_write_buffer(ctx, ctx->lsm_name, SECURITY_NAME_MAX + 1);
> >>> + if (ret < 0)
> >>> + return ret;
> >>> +
> >>> + ret = security_checkpoint_header(ctx);
> >>> + if (ret < 0)
> >>> + return ret;
> >>> +
> >> This is actually a case for a 'container-global' section that would
> >> appear after the header and before the rest of the image. (Would be
> >> useful also for network namespaces).
> >
> > But LSM's are specifically not containerized, so this is a host
> > property, not a container one.
>
> Hmmm... does that mean you can't apply one policy to one container
> and another policy to another ?
Yup.
> Anyway, it belongs to a 'global' section, that may have 2 parts:
> host and container. (Putting it between header and arch-header
> seems weird...)
Ok, then I'll add that in the next set.
> The header doesn't hold state, it is a declarative section about
> the properties of the original host (kernel and HW).
Ok, I see.
thanks,
-serge
--
This message was distributed to subscribers of the selinux mailing list.
If you no longer wish to subscribe, send mail to majordomo@tycho.nsa.gov with
the words "unsubscribe selinux" without quotes as the message.
^ permalink raw reply [flat|nested] 22+ messages in thread
end of thread, other threads:[~2009-10-02 22:32 UTC | newest]
Thread overview: 22+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2009-10-02 3:49 [PATCH 1/3] cr: add generic LSM c/r support (v4) Serge E. Hallyn
2009-10-02 3:49 ` Serge E. Hallyn
2009-10-02 3:52 ` [PATCH 2/3] cr: add smack support to lsm c/r (v4) Serge E. Hallyn
2009-10-02 3:52 ` [PATCH 3/3] cr: add selinux support (v4) Serge E. Hallyn
2009-10-02 3:52 ` Serge E. Hallyn
2009-10-02 12:59 ` Stephen Smalley
2009-10-02 12:59 ` Stephen Smalley
2009-10-02 21:55 ` Serge E. Hallyn
2009-10-02 21:55 ` Serge E. Hallyn
2009-10-02 21:14 ` Oren Laadan
2009-10-02 22:05 ` Serge E. Hallyn
2009-10-02 22:05 ` Serge E. Hallyn
2009-10-02 22:14 ` Serge E. Hallyn
2009-10-02 22:14 ` Serge E. Hallyn
[not found] ` <20091002034916.GA16871-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
2009-10-02 3:51 ` [PATCH 1/1] restart: accept the lsm_name field in header and add -k flag Serge E. Hallyn
[not found] ` <20091002035157.GA16920-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
2009-10-02 21:02 ` Oren Laadan
2009-10-02 20:57 ` [PATCH 1/3] cr: add generic LSM c/r support (v4) Oren Laadan
2009-10-02 22:13 ` Serge E. Hallyn
2009-10-02 22:13 ` Serge E. Hallyn
2009-10-02 22:23 ` Oren Laadan
2009-10-02 22:31 ` Serge E. Hallyn
2009-10-02 22:31 ` Serge E. Hallyn
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.