* [RFC PATCH v2 1/5] kdbus: add creator credentials to the endpoints
2015-10-05 20:41 [RFC PATCH v2 0/5] kdbus LSM/SELinux hooks Paul Moore
@ 2015-10-05 20:41 ` Paul Moore
2015-10-05 20:41 ` [RFC PATCH v2 2/5] lsm: introduce hooks for kdbus Paul Moore
` (3 subsequent siblings)
4 siblings, 0 replies; 8+ messages in thread
From: Paul Moore @ 2015-10-05 20:41 UTC (permalink / raw)
To: linux-security-module; +Cc: linux-audit, selinux
In order to effectively enforce LSM based access controls we need to
have more information about the kdbus endpoint creator than the
uid/gid currently stored in the kdbus_node_type struct. This patch
replaces the uid/gid values with a reference to the node creator's
credential struct which serves the needs of both the kdbus DAC access
controls as well as the LSM's access controls.
Two macros have also been created, kdbus_node_[uid,gid](), which can
be used to easily extract the euid/egid information from the new
credential reference. The effective uid/gid is used as it was used
in all areas of the previous kdbus code except for areas where the
uid/gid was never set beyond the basic initialization to zero/root;
I expect this was a bug that was never caught as the node creator in
these cases was always expect to be root.
Signed-off-by: Paul Moore <pmoore@redhat.com>
---
ChangeLog:
- v2
* Initial draft
---
ipc/kdbus/bus.c | 13 +++++--------
ipc/kdbus/endpoint.c | 14 ++++----------
ipc/kdbus/endpoint.h | 3 +--
ipc/kdbus/fs.c | 4 ++--
ipc/kdbus/node.c | 11 ++++-------
ipc/kdbus/node.h | 5 +++--
6 files changed, 19 insertions(+), 31 deletions(-)
diff --git a/ipc/kdbus/bus.c b/ipc/kdbus/bus.c
index a67f825..0cb9501 100644
--- a/ipc/kdbus/bus.c
+++ b/ipc/kdbus/bus.c
@@ -65,8 +65,7 @@ static void kdbus_bus_release(struct kdbus_node *node, bool was_active)
static struct kdbus_bus *kdbus_bus_new(struct kdbus_domain *domain,
const char *name,
struct kdbus_bloom_parameter *bloom,
- const u64 *pattach_owner,
- u64 flags, kuid_t uid, kgid_t gid)
+ const u64 *pattach_owner, u64 flags)
{
struct kdbus_bus *b;
u64 attach_owner;
@@ -81,7 +80,8 @@ static struct kdbus_bus *kdbus_bus_new(struct kdbus_domain *domain,
if (ret < 0)
return ERR_PTR(ret);
- ret = kdbus_verify_uid_prefix(name, domain->user_namespace, uid);
+ ret = kdbus_verify_uid_prefix(name, domain->user_namespace,
+ current_euid());
if (ret < 0)
return ERR_PTR(ret);
@@ -93,8 +93,6 @@ static struct kdbus_bus *kdbus_bus_new(struct kdbus_domain *domain,
b->node.free_cb = kdbus_bus_free;
b->node.release_cb = kdbus_bus_release;
- b->node.uid = uid;
- b->node.gid = gid;
b->node.mode = S_IRUSR | S_IXUSR;
if (flags & (KDBUS_MAKE_ACCESS_GROUP | KDBUS_MAKE_ACCESS_WORLD))
@@ -374,7 +372,7 @@ struct kdbus_bus *kdbus_cmd_bus_make(struct kdbus_domain *domain,
bus = kdbus_bus_new(domain,
argv[1].item->str, &argv[2].item->bloom_parameter,
argv[3].item ? argv[3].item->data64 : NULL,
- cmd->flags, current_euid(), current_egid());
+ cmd->flags);
if (IS_ERR(bus)) {
ret = PTR_ERR(bus);
bus = NULL;
@@ -393,8 +391,7 @@ struct kdbus_bus *kdbus_cmd_bus_make(struct kdbus_domain *domain,
goto exit;
}
- ep = kdbus_ep_new(bus, "bus", cmd->flags, bus->node.uid, bus->node.gid,
- false);
+ ep = kdbus_ep_new(bus, "bus", cmd->flags, false);
if (IS_ERR(ep)) {
ret = PTR_ERR(ep);
ep = NULL;
diff --git a/ipc/kdbus/endpoint.c b/ipc/kdbus/endpoint.c
index 44e7a20..1ba5d51 100644
--- a/ipc/kdbus/endpoint.c
+++ b/ipc/kdbus/endpoint.c
@@ -74,8 +74,6 @@ static void kdbus_ep_release(struct kdbus_node *node, bool was_active)
* @bus: The bus this endpoint will be created for
* @name: The name of the endpoint
* @access: The access flags for this node (KDBUS_MAKE_ACCESS_*)
- * @uid: The uid of the node
- * @gid: The gid of the node
* @is_custom: Whether this is a custom endpoint
*
* This function will create a new endpoint with the given
@@ -84,8 +82,7 @@ static void kdbus_ep_release(struct kdbus_node *node, bool was_active)
* Return: a new kdbus_ep on success, ERR_PTR on failure.
*/
struct kdbus_ep *kdbus_ep_new(struct kdbus_bus *bus, const char *name,
- unsigned int access, kuid_t uid, kgid_t gid,
- bool is_custom)
+ unsigned int access, bool is_custom)
{
struct kdbus_ep *e;
int ret;
@@ -96,7 +93,7 @@ struct kdbus_ep *kdbus_ep_new(struct kdbus_bus *bus, const char *name,
*/
if (is_custom) {
ret = kdbus_verify_uid_prefix(name, bus->domain->user_namespace,
- uid);
+ current_euid());
if (ret < 0)
return ERR_PTR(ret);
}
@@ -109,8 +106,6 @@ struct kdbus_ep *kdbus_ep_new(struct kdbus_bus *bus, const char *name,
e->node.free_cb = kdbus_ep_free;
e->node.release_cb = kdbus_ep_release;
- e->node.uid = uid;
- e->node.gid = gid;
e->node.mode = S_IRUSR | S_IWUSR;
if (access & (KDBUS_MAKE_ACCESS_GROUP | KDBUS_MAKE_ACCESS_WORLD))
e->node.mode |= S_IRGRP | S_IWGRP;
@@ -207,7 +202,7 @@ bool kdbus_ep_is_privileged(struct kdbus_ep *ep, struct file *file)
bool kdbus_ep_is_owner(struct kdbus_ep *ep, struct file *file)
{
return !ep->user &&
- (uid_eq(file->f_cred->euid, ep->bus->node.uid) ||
+ (uid_eq(file->f_cred->euid, kdbus_node_uid(&ep->bus->node)) ||
kdbus_ep_is_privileged(ep, file));
}
@@ -245,8 +240,7 @@ struct kdbus_ep *kdbus_cmd_ep_make(struct kdbus_bus *bus, void __user *argp)
item_make_name = argv[1].item->str;
- ep = kdbus_ep_new(bus, item_make_name, cmd->flags,
- current_euid(), current_egid(), true);
+ ep = kdbus_ep_new(bus, item_make_name, cmd->flags, true);
if (IS_ERR(ep)) {
ret = PTR_ERR(ep);
ep = NULL;
diff --git a/ipc/kdbus/endpoint.h b/ipc/kdbus/endpoint.h
index e0da59f..c537779 100644
--- a/ipc/kdbus/endpoint.h
+++ b/ipc/kdbus/endpoint.h
@@ -56,8 +56,7 @@ struct kdbus_ep {
container_of((_node), struct kdbus_ep, node)
struct kdbus_ep *kdbus_ep_new(struct kdbus_bus *bus, const char *name,
- unsigned int access, kuid_t uid, kgid_t gid,
- bool policy);
+ unsigned int access, bool policy);
struct kdbus_ep *kdbus_ep_ref(struct kdbus_ep *ep);
struct kdbus_ep *kdbus_ep_unref(struct kdbus_ep *ep);
diff --git a/ipc/kdbus/fs.c b/ipc/kdbus/fs.c
index 09c4809..68818a8 100644
--- a/ipc/kdbus/fs.c
+++ b/ipc/kdbus/fs.c
@@ -204,8 +204,8 @@ static struct inode *fs_inode_get(struct super_block *sb,
inode->i_mapping->a_ops = &empty_aops;
inode->i_mode = node->mode & S_IALLUGO;
inode->i_atime = inode->i_ctime = inode->i_mtime = CURRENT_TIME;
- inode->i_uid = node->uid;
- inode->i_gid = node->gid;
+ inode->i_uid = kdbus_node_uid(node);
+ inode->i_gid = kdbus_node_gid(node);
switch (node->type) {
case KDBUS_NODE_DOMAIN:
diff --git a/ipc/kdbus/node.c b/ipc/kdbus/node.c
index 89f58bc..cd0c1a0 100644
--- a/ipc/kdbus/node.c
+++ b/ipc/kdbus/node.c
@@ -12,6 +12,7 @@
*/
#include <linux/atomic.h>
+#include <linux/cred.h>
#include <linux/fs.h>
#include <linux/idr.h>
#include <linux/kdev_t.h>
@@ -170,13 +171,7 @@
* node initialization. They must remain constant. If
* NULL, they're skipped.
*
- * * node->mode: filesystem access modes
- * node->uid: filesystem owner uid
- * node->gid: filesystem owner gid
- * These fields must be set by the node owner during node
- * initialization. They must remain constant and may be
- * accessed by other callers to properly initialize
- * filesystem nodes.
+ * * node->creds: The credentials of the node's creator
*
* * node->id: This is an unsigned 32bit integer allocated by an IDA. It is
* always kept as small as possible during allocation and is
@@ -293,6 +288,7 @@ void kdbus_node_init(struct kdbus_node *node, unsigned int type)
mutex_init(&node->lock);
node->id = 0;
node->type = type;
+ node->creds = get_current_cred();
RB_CLEAR_NODE(&node->rb);
node->children = RB_ROOT;
init_waitqueue_head(&node->waitq);
@@ -433,6 +429,7 @@ struct kdbus_node *kdbus_node_unref(struct kdbus_node *node)
WARN_ON(atomic_read(&node->active) != KDBUS_NODE_DRAINED);
WARN_ON(!RB_EMPTY_NODE(&node->rb));
+ put_cred(node->creds);
if (node->free_cb)
node->free_cb(node);
if (safe.id > 0)
diff --git a/ipc/kdbus/node.h b/ipc/kdbus/node.h
index 970e02b..d52e1c2 100644
--- a/ipc/kdbus/node.h
+++ b/ipc/kdbus/node.h
@@ -41,8 +41,7 @@ struct kdbus_node {
kdbus_node_free_t free_cb;
kdbus_node_release_t release_cb;
umode_t mode;
- kuid_t uid;
- kgid_t gid;
+ const struct cred *creds;
/* valid once linked */
char *name;
@@ -57,6 +56,8 @@ struct kdbus_node {
};
#define kdbus_node_from_rb(_node) rb_entry((_node), struct kdbus_node, rb)
+#define kdbus_node_uid(_node) ((_node)->creds->euid)
+#define kdbus_node_gid(_node) ((_node)->creds->egid)
extern struct ida kdbus_node_ida;
^ permalink raw reply related [flat|nested] 8+ messages in thread* [RFC PATCH v2 2/5] lsm: introduce hooks for kdbus
2015-10-05 20:41 [RFC PATCH v2 0/5] kdbus LSM/SELinux hooks Paul Moore
2015-10-05 20:41 ` [RFC PATCH v2 1/5] kdbus: add creator credentials to the endpoints Paul Moore
@ 2015-10-05 20:41 ` Paul Moore
2015-10-05 20:41 ` [RFC PATCH v2 3/5] lsm: add support for auditing kdbus service names Paul Moore
` (2 subsequent siblings)
4 siblings, 0 replies; 8+ messages in thread
From: Paul Moore @ 2015-10-05 20:41 UTC (permalink / raw)
To: linux-security-module; +Cc: linux-audit, selinux
Add LSM access control hooks to kdbus; several new hooks are added and
the existing security_file_receive() hook is reused. The new hooks
are listed below:
* security_kdbus_conn_new
Check if the current task is allowed to create a new kdbus
connection.
* security_kdbus_own_name
Check if a connection is allowed to own a kdbus service name.
* security_kdbus_conn_talk
Check if a connection is allowed to talk to a kdbus peer.
* security_kdbus_conn_see
Check if a connection can see a kdbus peer.
* security_kdbus_conn_see_name
Check if a connection can see a kdbus service name.
* security_kdbus_conn_see_notification
Check if a connection can receive notifications.
* security_kdbus_proc_permission
Check if a connection can access another task's pid namespace info.
* security_kdbus_init_inode
Set the security label on a kdbusfs inode
Signed-off-by: Paul Moore <pmoore@redhat.com>
---
ChangeLog:
- v2
* Implemented suggestions by Stephen Smalley
* call security_kdbus_conn_new() sooner
* reworked hook inside kdbus_conn_policy_own_name()
* fixed if-conditional in kdbus_conn_policy_talk()
* reworked hook inside kdbus_conn_policy_see_name_unlocked()
* reworked hook inside kdbus_conn_policy_see()
* reworked hook inside kdbus_conn_policy_see_notification()
* added the security_kdbus_init_inode() hook
- v1
* Initial draft
---
include/linux/security.h | 126 ++++++++++++++++++++++++++++++++++++++++++++++
ipc/kdbus/connection.c | 73 +++++++++++++++++----------
ipc/kdbus/fs.c | 6 ++
ipc/kdbus/message.c | 19 +++++--
ipc/kdbus/metadata.c | 6 +-
security/security.c | 50 ++++++++++++++++++
6 files changed, 245 insertions(+), 35 deletions(-)
diff --git a/include/linux/security.h b/include/linux/security.h
index 18264ea..7992663 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -53,6 +53,9 @@ struct msg_queue;
struct xattr;
struct xfrm_sec_ctx;
struct mm_struct;
+struct kdbus_creds;
+struct kdbus_pids;
+struct pid;
/* Maximum number of letters for an LSM name string */
#define SECURITY_NAME_MAX 10
@@ -1300,6 +1303,45 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
* @file contains the struct file being transferred.
* @to contains the task_struct for the receiving task.
*
+ * @kdbus_conn_new
+ * Check if the current task is allowed to create a new kdbus connection.
+ * @creds credentials for the new connection
+ * @fake_creds kdbus faked credentials
+ * @fake_pids kdbus faked pids
+ * @fake_seclabel kdbus faked security label
+ * @owner kdbus owner
+ * @privileged kdbus privileged
+ * @is_activator kdbus activator boolean
+ * @is_monitor kdbus monitor boolean
+ * @is_policy_holder kdbus policy holder boolean
+ * @kdbus_own_name
+ * Check if a connection is allowed to own a kdbus service name.
+ * @creds requestor's credentials
+ * @name service name
+ * @kdbus_conn_talk
+ * Check if a connection is allowed to talk to a kdbus peer.
+ * @creds requestor's credentials
+ * @creds_peer peer credentials
+ * @kdbus_conn_see
+ * Check if a connection can see a kdbus peer.
+ * @creds requestor's credentials
+ * @creds_peer peer credentials
+ * @kdbus_conn_see_name
+ * Check if a connection can see a kdbus service name.
+ * @creds requestor's credentials
+ * @name service name
+ * @kdbus_conn_see_notification
+ * Check if a connection can receive notifications.
+ * @creds requestor's credentials
+ * @kdbus_proc_permission
+ * Check if a connection can access another task's pid namespace info.
+ * @cred requestor's credentials
+ * @pid target task's pid struct
+ * @kdbus_init_inode
+ * Set the security label on a kdbusfs inode
+ * @inode kdbusfs inode
+ * @creds inode owner credentials
+ *
* @ptrace_access_check:
* Check permission before allowing the current process to trace the
* @child process.
@@ -1468,6 +1510,22 @@ struct security_operations {
int (*binder_transfer_file) (struct task_struct *from,
struct task_struct *to, struct file *file);
+ int (*kdbus_conn_new)(const struct cred *creds,
+ const struct kdbus_creds *fake_creds,
+ const struct kdbus_pids *fake_pids,
+ const char *fake_seclabel,
+ bool owner, bool privileged, bool is_activator,
+ bool is_monitor, bool is_policy_holder);
+ int (*kdbus_own_name)(const struct cred *creds, const char *name);
+ int (*kdbus_conn_talk)(const struct cred *creds,
+ const struct cred *creds_peer);
+ int (*kdbus_conn_see)(const struct cred *creds,
+ const struct cred *creds_peer);
+ int (*kdbus_conn_see_name)(const struct cred *creds, const char *name);
+ int (*kdbus_conn_see_notification)(const struct cred *creds);
+ int (*kdbus_proc_permission)(const struct cred *creds, struct pid *pid);
+ int (*kdbus_init_inode)(struct inode *inode, const struct cred *creds);
+
int (*ptrace_access_check) (struct task_struct *child, unsigned int mode);
int (*ptrace_traceme) (struct task_struct *parent);
int (*capget) (struct task_struct *target,
@@ -1772,6 +1830,21 @@ int security_binder_transfer_binder(struct task_struct *from,
struct task_struct *to);
int security_binder_transfer_file(struct task_struct *from,
struct task_struct *to, struct file *file);
+int security_kdbus_conn_new(const struct cred *creds,
+ const struct kdbus_creds *fake_creds,
+ const struct kdbus_pids *fake_pids,
+ const char *fake_seclabel,
+ bool owner, bool privileged, bool is_activator,
+ bool is_monitor, bool is_policy_holder);
+int security_kdbus_own_name(const struct cred *creds, const char *name);
+int security_kdbus_conn_talk(const struct cred *creds,
+ const struct cred *creds_peer);
+int security_kdbus_conn_see(const struct cred *creds,
+ const struct cred *creds_peer);
+int security_kdbus_conn_see_name(const struct cred *creds, const char *name);
+int security_kdbus_conn_see_notification(const struct cred *creds);
+int security_kdbus_proc_permission(const struct cred *creds, struct pid *pid);
+int security_kdbus_init_inode(struct inode *inode, const struct cred *creds);
int security_ptrace_access_check(struct task_struct *child, unsigned int mode);
int security_ptrace_traceme(struct task_struct *parent);
int security_capget(struct task_struct *target,
@@ -1984,6 +2057,59 @@ static inline int security_binder_transfer_file(struct task_struct *from,
return 0;
}
+static inline int security_kdbus_conn_new(const struct cred *creds,
+ const struct kdbus_creds *fake_creds,
+ const struct kdbus_pids *fake_pids,
+ const char *fake_seclabel,
+ bool owner, bool privileged,
+ bool is_activator,
+ bool is_monitor,
+ bool is_policy_holder)
+{
+ return 0;
+}
+
+static inline int security_kdbus_own_name(const struct cred *creds,
+ const char *name)
+{
+ return 0;
+}
+
+static inline int security_kdbus_conn_talk(const struct cred *creds,
+ const struct cred *creds_peer)
+{
+ return 0;
+}
+
+static inline int security_kdbus_conn_see(const struct cred *creds,
+ const struct cred *creds_peer)
+{
+ return 0;
+}
+
+static inline int security_kdbus_conn_see_name(const struct cred *creds,
+ const char *name)
+{
+ return 0;
+}
+
+static inline int security_kdbus_conn_see_notification(const struct cred *creds)
+{
+ return 0;
+}
+
+static inline int security_kdbus_proc_permission)(const struct cred *creds,
+ struct pid *pid)
+{
+ return 0;
+}
+
+static inline int security_kdbus_init_inode(struct inode *inode,
+ const struct *creds)
+{
+ return 0;
+}
+
static inline int security_ptrace_access_check(struct task_struct *child,
unsigned int mode)
{
diff --git a/ipc/kdbus/connection.c b/ipc/kdbus/connection.c
index ef63d65..1cb87b3 100644
--- a/ipc/kdbus/connection.c
+++ b/ipc/kdbus/connection.c
@@ -26,6 +26,7 @@
#include <linux/path.h>
#include <linux/poll.h>
#include <linux/sched.h>
+#include <linux/security.h>
#include <linux/shmem_fs.h>
#include <linux/sizes.h>
#include <linux/slab.h>
@@ -108,6 +109,14 @@ static struct kdbus_conn *kdbus_conn_new(struct kdbus_ep *ep,
if (!owner && (creds || pids || seclabel))
return ERR_PTR(-EPERM);
+ ret = security_kdbus_conn_new(get_cred(file->f_cred),
+ creds, pids, seclabel,
+ owner, privileged,
+ is_activator, is_monitor,
+ is_policy_holder);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
ret = kdbus_sanitize_attach_flags(hello->attach_flags_send,
&attach_flags_send);
if (ret < 0)
@@ -1435,12 +1444,12 @@ bool kdbus_conn_policy_own_name(struct kdbus_conn *conn,
return false;
}
- if (conn->owner)
- return true;
+ if (!conn->owner &&
+ kdbus_policy_query(&conn->ep->bus->policy_db, conn_creds, name,
+ hash) < KDBUS_POLICY_OWN)
+ return false;
- res = kdbus_policy_query(&conn->ep->bus->policy_db, conn_creds,
- name, hash);
- return res >= KDBUS_POLICY_OWN;
+ return (security_kdbus_own_name(conn_creds, name) == 0);
}
/**
@@ -1465,14 +1474,13 @@ bool kdbus_conn_policy_talk(struct kdbus_conn *conn,
to, KDBUS_POLICY_TALK))
return false;
- if (conn->owner)
- return true;
- if (uid_eq(conn_creds->euid, to->cred->uid))
- return true;
+ if (!conn->owner && !uid_eq(conn_creds->euid, to->cred->uid) &&
+ !kdbus_conn_policy_query_all(conn, conn_creds,
+ &conn->ep->bus->policy_db, to,
+ KDBUS_POLICY_TALK))
+ return false;
- return kdbus_conn_policy_query_all(conn, conn_creds,
- &conn->ep->bus->policy_db, to,
- KDBUS_POLICY_TALK);
+ return (security_kdbus_conn_talk(conn_creds, to->cred) == 0);
}
/**
@@ -1491,19 +1499,19 @@ bool kdbus_conn_policy_see_name_unlocked(struct kdbus_conn *conn,
const struct cred *conn_creds,
const char *name)
{
- int res;
+ if (!conn_creds)
+ conn_creds = conn->cred;
/*
* By default, all names are visible on a bus. SEE policies can only be
* installed on custom endpoints, where by default no name is visible.
*/
- if (!conn->ep->user)
- return true;
+ if (conn->ep->user &&
+ kdbus_policy_query_unlocked(&conn->ep->policy_db, conn_creds, name,
+ kdbus_strhash(name)) < KDBUS_POLICY_SEE)
+ return false;
- res = kdbus_policy_query_unlocked(&conn->ep->policy_db,
- conn_creds ? : conn->cred,
- name, kdbus_strhash(name));
- return res >= KDBUS_POLICY_SEE;
+ return (security_kdbus_conn_see_name(conn_creds, name) == 0);
}
static bool kdbus_conn_policy_see_name(struct kdbus_conn *conn,
@@ -1523,6 +1531,9 @@ static bool kdbus_conn_policy_see(struct kdbus_conn *conn,
const struct cred *conn_creds,
struct kdbus_conn *whom)
{
+ if (!conn_creds)
+ conn_creds = conn->cred;
+
/*
* By default, all names are visible on a bus, so a connection can
* always see other connections. SEE policies can only be installed on
@@ -1530,10 +1541,13 @@ static bool kdbus_conn_policy_see(struct kdbus_conn *conn,
* peers from each other, unless you see at least _one_ name of the
* peer.
*/
- return !conn->ep->user ||
- kdbus_conn_policy_query_all(conn, conn_creds,
- &conn->ep->policy_db, whom,
- KDBUS_POLICY_SEE);
+ if (conn->ep->user &&
+ !kdbus_conn_policy_query_all(conn, conn_creds,
+ &conn->ep->policy_db, whom,
+ KDBUS_POLICY_SEE))
+ return false;
+
+ return (security_kdbus_conn_see(conn_creds, whom->cred) == 0);
}
/**
@@ -1551,6 +1565,9 @@ bool kdbus_conn_policy_see_notification(struct kdbus_conn *conn,
const struct cred *conn_creds,
const struct kdbus_msg *msg)
{
+ if (!conn_creds)
+ conn_creds = conn->cred;
+
/*
* Depending on the notification type, broadcasted kernel notifications
* have to be filtered:
@@ -1567,18 +1584,22 @@ bool kdbus_conn_policy_see_notification(struct kdbus_conn *conn,
case KDBUS_ITEM_NAME_ADD:
case KDBUS_ITEM_NAME_REMOVE:
case KDBUS_ITEM_NAME_CHANGE:
- return kdbus_conn_policy_see_name(conn, conn_creds,
- msg->items[0].name_change.name);
+ if (!kdbus_conn_policy_see_name(conn, conn_creds,
+ msg->items[0].name_change.name))
+ return false;
case KDBUS_ITEM_ID_ADD:
case KDBUS_ITEM_ID_REMOVE:
- return true;
+ /* fall through for the LSM check */
+ break;
default:
WARN(1, "Invalid type for notification broadcast: %llu\n",
(unsigned long long)msg->items[0].type);
return false;
}
+
+ return (security_kdbus_conn_see_notification(conn_creds) == 0);
}
/**
diff --git a/ipc/kdbus/fs.c b/ipc/kdbus/fs.c
index 68818a8..4e84e89 100644
--- a/ipc/kdbus/fs.c
+++ b/ipc/kdbus/fs.c
@@ -23,6 +23,7 @@
#include <linux/namei.h>
#include <linux/pagemap.h>
#include <linux/sched.h>
+#include <linux/security.h>
#include <linux/slab.h>
#include "bus.h"
@@ -192,6 +193,7 @@ static const struct inode_operations fs_inode_iops = {
static struct inode *fs_inode_get(struct super_block *sb,
struct kdbus_node *node)
{
+ int ret;
struct inode *inode;
inode = iget_locked(sb, node->id);
@@ -200,6 +202,10 @@ static struct inode *fs_inode_get(struct super_block *sb,
if (!(inode->i_state & I_NEW))
return inode;
+ ret = security_kdbus_init_inode(inode, node->creds);
+ if (ret)
+ return ERR_PTR(ret);
+
inode->i_private = kdbus_node_ref(node);
inode->i_mapping->a_ops = &empty_aops;
inode->i_mode = node->mode & S_IALLUGO;
diff --git a/ipc/kdbus/message.c b/ipc/kdbus/message.c
index ae565cd..acbe981 100644
--- a/ipc/kdbus/message.c
+++ b/ipc/kdbus/message.c
@@ -150,12 +150,17 @@ int kdbus_gaps_install(struct kdbus_gaps *gaps, struct kdbus_pool_slice *slice,
for (i = 0; i < gaps->n_fds; ++i) {
int fd;
+ ret = security_file_receive(gaps->fd_files[i]);
+ if (ret) {
+ incomplete_fds = true;
+ fds[n_fds++] = -1;
+ continue;
+ }
+
fd = get_unused_fd_flags(O_CLOEXEC);
if (fd < 0)
incomplete_fds = true;
- WARN_ON(!gaps->fd_files[i]);
-
fds[n_fds++] = fd < 0 ? -1 : fd;
}
@@ -178,6 +183,13 @@ int kdbus_gaps_install(struct kdbus_gaps *gaps, struct kdbus_pool_slice *slice,
for (i = 0; i < gaps->n_memfds; ++i) {
int memfd;
+ ret = security_file_receive(gaps->memfd_files[i]);
+ if (ret) {
+ incomplete_fds = true;
+ fds[n_fds++] = -1;
+ continue;
+ }
+
memfd = get_unused_fd_flags(O_CLOEXEC);
if (memfd < 0) {
incomplete_fds = true;
@@ -194,9 +206,6 @@ int kdbus_gaps_install(struct kdbus_gaps *gaps, struct kdbus_pool_slice *slice,
* message.
*/
- WARN_ON(!gaps->memfd_offsets[i]);
- WARN_ON(!gaps->memfd_files[i]);
-
kvec.iov_base = &memfd;
kvec.iov_len = sizeof(memfd);
ret = kdbus_pool_slice_copy_kvec(slice, gaps->memfd_offsets[i],
diff --git a/ipc/kdbus/metadata.c b/ipc/kdbus/metadata.c
index 71ca475..07c45d7 100644
--- a/ipc/kdbus/metadata.c
+++ b/ipc/kdbus/metadata.c
@@ -1182,11 +1182,9 @@ static unsigned int kdbus_proc_permission(const struct pid_namespace *pid_ns,
const struct cred *cred,
struct pid *target)
{
- if (pid_ns->hide_pid < 1)
- return KDBUS_META_PROC_NORMAL;
-
/* XXX: we need groups_search() exported for aux-groups */
- if (gid_eq(cred->egid, pid_ns->pid_gid))
+ if ((pid_ns->hide_pid < 1 || gid_eq(cred->egid, pid_ns->pid_gid)) &&
+ security_kdbus_proc_permission(cred, target) == 0)
return KDBUS_META_PROC_NORMAL;
/*
diff --git a/security/security.c b/security/security.c
index 8e9b1f4..2e5ce04 100644
--- a/security/security.c
+++ b/security/security.c
@@ -158,6 +158,56 @@ int security_binder_transfer_file(struct task_struct *from,
return security_ops->binder_transfer_file(from, to, file);
}
+int security_kdbus_conn_new(const struct cred *creds,
+ const struct kdbus_creds *fake_creds,
+ const struct kdbus_pids *fake_pids,
+ const char *fake_seclabel,
+ bool owner, bool privileged, bool is_activator,
+ bool is_monitor, bool is_policy_holder)
+{
+ return security_ops->kdbus_conn_new(creds, fake_creds, fake_pids,
+ fake_seclabel, owner, privileged,
+ is_activator, is_monitor,
+ is_policy_holder);
+}
+
+int security_kdbus_own_name(const struct cred *creds, const char *name)
+{
+ return security_ops->kdbus_own_name(creds, name);
+}
+
+int security_kdbus_conn_talk(const struct cred *creds,
+ const struct cred *creds_peer)
+{
+ return security_ops->kdbus_conn_talk(creds, creds_peer);
+}
+
+int security_kdbus_conn_see(const struct cred *creds,
+ const struct cred *creds_peer)
+{
+ return security_ops->kdbus_conn_see(creds, creds_peer);
+}
+
+int security_kdbus_conn_see_name(const struct cred *creds, const char *name)
+{
+ return security_ops->kdbus_conn_see_name(creds, name);
+}
+
+int security_kdbus_conn_see_notification(const struct cred *creds)
+{
+ return security_ops->kdbus_conn_see_notification(creds);
+}
+
+int security_kdbus_proc_permission(const struct cred *creds, struct pid *pid)
+{
+ return security_ops->kdbus_proc_permission(creds, pid);
+}
+
+int security_kdbus_init_inode(struct inode *inode, const struct cred *creds)
+{
+ return security_ops->kdbus_init_inode(inode, creds);
+}
+
int security_ptrace_access_check(struct task_struct *child, unsigned int mode)
{
#ifdef CONFIG_SECURITY_YAMA_STACKED
^ permalink raw reply related [flat|nested] 8+ messages in thread* [RFC PATCH v2 3/5] lsm: add support for auditing kdbus service names
2015-10-05 20:41 [RFC PATCH v2 0/5] kdbus LSM/SELinux hooks Paul Moore
2015-10-05 20:41 ` [RFC PATCH v2 1/5] kdbus: add creator credentials to the endpoints Paul Moore
2015-10-05 20:41 ` [RFC PATCH v2 2/5] lsm: introduce hooks for kdbus Paul Moore
@ 2015-10-05 20:41 ` Paul Moore
2015-10-05 20:41 ` [RFC PATCH v2 4/5] selinux: introduce kdbus names into the policy Paul Moore
2015-10-05 20:41 ` [RFC PATCH v2 5/5] selinux: introduce kdbus access controls Paul Moore
4 siblings, 0 replies; 8+ messages in thread
From: Paul Moore @ 2015-10-05 20:41 UTC (permalink / raw)
To: linux-security-module; +Cc: linux-audit, selinux
The kdbus service names will be recorded using 'service', similar to
the existing dbus audit records.
Signed-off-by: Paul Moore <pmoore@redhat.com>
---
ChangeLog:
- v2
* Initial draft
---
include/linux/lsm_audit.h | 2 ++
security/lsm_audit.c | 4 ++++
2 files changed, 6 insertions(+)
diff --git a/include/linux/lsm_audit.h b/include/linux/lsm_audit.h
index ffb9c9d..d6a656f 100644
--- a/include/linux/lsm_audit.h
+++ b/include/linux/lsm_audit.h
@@ -59,6 +59,7 @@ struct common_audit_data {
#define LSM_AUDIT_DATA_INODE 9
#define LSM_AUDIT_DATA_DENTRY 10
#define LSM_AUDIT_DATA_IOCTL_OP 11
+#define LSM_AUDIT_DATA_KDBUS 12
union {
struct path path;
struct dentry *dentry;
@@ -75,6 +76,7 @@ struct common_audit_data {
#endif
char *kmod_name;
struct lsm_ioctlop_audit *op;
+ const char *kdbus_name;
} u;
/* this union contains LSM specific data */
union {
diff --git a/security/lsm_audit.c b/security/lsm_audit.c
index 9f6c649..d7af41d 100644
--- a/security/lsm_audit.c
+++ b/security/lsm_audit.c
@@ -397,6 +397,10 @@ static void dump_common_audit_data(struct audit_buffer *ab,
audit_log_format(ab, " kmod=");
audit_log_untrustedstring(ab, a->u.kmod_name);
break;
+ case LSM_AUDIT_DATA_KDBUS:
+ audit_log_format(ab, " service=");
+ audit_log_untrustedstring(ab, a->u.kdbus_name);
+ break;
} /* switch (a->type) */
}
^ permalink raw reply related [flat|nested] 8+ messages in thread* [RFC PATCH v2 4/5] selinux: introduce kdbus names into the policy
2015-10-05 20:41 [RFC PATCH v2 0/5] kdbus LSM/SELinux hooks Paul Moore
` (2 preceding siblings ...)
2015-10-05 20:41 ` [RFC PATCH v2 3/5] lsm: add support for auditing kdbus service names Paul Moore
@ 2015-10-05 20:41 ` Paul Moore
2015-10-05 20:41 ` [RFC PATCH v2 5/5] selinux: introduce kdbus access controls Paul Moore
4 siblings, 0 replies; 8+ messages in thread
From: Paul Moore @ 2015-10-05 20:41 UTC (permalink / raw)
To: linux-security-module; +Cc: linux-audit, selinux
SELinux treats kdbus service names as objects and therefore needs a
mechanism to map service names to security labels. This patch adds
support for loading kdbus name/label matches with the security policy.
The patch supports service name prefix matching to lessen the burden
on the policy developers and reduce the size of the resulting policy.
Signed-off-by: Paul Moore <pmoore@redhat.com>
---
ChangeLog:
- v2
* Porting needed to work with ioctl xperms
- v1
* Initial draft
---
security/selinux/include/security.h | 5 ++
security/selinux/ss/policydb.c | 88 +++++++++++++++++++++++++++++------
security/selinux/ss/policydb.h | 3 +
security/selinux/ss/services.c | 38 +++++++++++++++
4 files changed, 116 insertions(+), 18 deletions(-)
diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
index eb9a549..3219b5d 100644
--- a/security/selinux/include/security.h
+++ b/security/selinux/include/security.h
@@ -36,13 +36,14 @@
#define POLICYDB_VERSION_DEFAULT_TYPE 28
#define POLICYDB_VERSION_CONSTRAINT_NAMES 29
#define POLICYDB_VERSION_XPERMS_IOCTL 30
+#define POLICYDB_VERSION_KDBUS 31
/* Range of policy versions we understand*/
#define POLICYDB_VERSION_MIN POLICYDB_VERSION_BASE
#ifdef CONFIG_SECURITY_SELINUX_POLICYDB_VERSION_MAX
#define POLICYDB_VERSION_MAX CONFIG_SECURITY_SELINUX_POLICYDB_VERSION_MAX_VALUE
#else
-#define POLICYDB_VERSION_MAX POLICYDB_VERSION_XPERMS_IOCTL
+#define POLICYDB_VERSION_MAX POLICYDB_VERSION_KDBUS
#endif
/* Mask for just the mount related flags */
@@ -211,6 +212,8 @@ int security_fs_use(struct super_block *sb);
int security_genfs_sid(const char *fstype, char *name, u16 sclass,
u32 *sid);
+int security_kdbus_sid(const char *name, u32 *sid);
+
#ifdef CONFIG_NETLABEL
int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
u32 *sid);
diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index 992a315..9be2e6d 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -76,81 +76,86 @@ static struct policydb_compat_info policydb_compat[] = {
{
.version = POLICYDB_VERSION_BASE,
.sym_num = SYM_NUM - 3,
- .ocon_num = OCON_NUM - 1,
+ .ocon_num = OCON_NUM - 2,
},
{
.version = POLICYDB_VERSION_BOOL,
.sym_num = SYM_NUM - 2,
- .ocon_num = OCON_NUM - 1,
+ .ocon_num = OCON_NUM - 2,
},
{
.version = POLICYDB_VERSION_IPV6,
.sym_num = SYM_NUM - 2,
- .ocon_num = OCON_NUM,
+ .ocon_num = OCON_NUM - 1,
},
{
.version = POLICYDB_VERSION_NLCLASS,
.sym_num = SYM_NUM - 2,
- .ocon_num = OCON_NUM,
+ .ocon_num = OCON_NUM - 1,
},
{
.version = POLICYDB_VERSION_MLS,
.sym_num = SYM_NUM,
- .ocon_num = OCON_NUM,
+ .ocon_num = OCON_NUM - 1,
},
{
.version = POLICYDB_VERSION_AVTAB,
.sym_num = SYM_NUM,
- .ocon_num = OCON_NUM,
+ .ocon_num = OCON_NUM - 1,
},
{
.version = POLICYDB_VERSION_RANGETRANS,
.sym_num = SYM_NUM,
- .ocon_num = OCON_NUM,
+ .ocon_num = OCON_NUM - 1,
},
{
.version = POLICYDB_VERSION_POLCAP,
.sym_num = SYM_NUM,
- .ocon_num = OCON_NUM,
+ .ocon_num = OCON_NUM - 1,
},
{
.version = POLICYDB_VERSION_PERMISSIVE,
.sym_num = SYM_NUM,
- .ocon_num = OCON_NUM,
+ .ocon_num = OCON_NUM - 1,
},
{
.version = POLICYDB_VERSION_BOUNDARY,
.sym_num = SYM_NUM,
- .ocon_num = OCON_NUM,
+ .ocon_num = OCON_NUM - 1,
},
{
.version = POLICYDB_VERSION_FILENAME_TRANS,
.sym_num = SYM_NUM,
- .ocon_num = OCON_NUM,
+ .ocon_num = OCON_NUM - 1,
},
{
.version = POLICYDB_VERSION_ROLETRANS,
.sym_num = SYM_NUM,
- .ocon_num = OCON_NUM,
+ .ocon_num = OCON_NUM - 1,
},
{
.version = POLICYDB_VERSION_NEW_OBJECT_DEFAULTS,
.sym_num = SYM_NUM,
- .ocon_num = OCON_NUM,
+ .ocon_num = OCON_NUM - 1,
},
{
.version = POLICYDB_VERSION_DEFAULT_TYPE,
.sym_num = SYM_NUM,
- .ocon_num = OCON_NUM,
+ .ocon_num = OCON_NUM - 1,
},
{
.version = POLICYDB_VERSION_CONSTRAINT_NAMES,
.sym_num = SYM_NUM,
- .ocon_num = OCON_NUM,
+ .ocon_num = OCON_NUM - 1,
},
{
.version = POLICYDB_VERSION_XPERMS_IOCTL,
.sym_num = SYM_NUM,
+ .ocon_num = OCON_NUM - 1,
+ },
+ {
+ .version = POLICYDB_VERSION_KDBUS,
+ .sym_num = SYM_NUM,
.ocon_num = OCON_NUM,
},
};
@@ -2111,7 +2116,7 @@ static int ocontext_read(struct policydb *p, struct policydb_compat_info *info,
int i, j, rc;
u32 nel, len;
__le32 buf[3];
- struct ocontext *l, *c;
+ struct ocontext *l, *l2, *c;
u32 nodebuf[8];
for (i = 0; i < info->ocon_num; i++) {
@@ -2130,6 +2135,7 @@ static int ocontext_read(struct policydb *p, struct policydb_compat_info *info,
l->next = c;
else
p->ocontexts[i] = c;
+ l2 = l;
l = c;
switch (i) {
@@ -2219,6 +2225,43 @@ static int ocontext_read(struct policydb *p, struct policydb_compat_info *info,
goto out;
break;
}
+ case OCON_KDBUS: {
+ struct ocontext *iter, *last;
+ u32 len2;
+
+ rc = next_entry(buf, fp, sizeof(u32));
+ if (rc)
+ goto out;
+ len = le32_to_cpu(buf[0]);
+ rc = str_read(&c->u.name, GFP_KERNEL, fp, len);
+ if (rc)
+ goto out;
+ rc = context_read_and_validate(&c->context[0], p, fp);
+ if (rc) {
+ kfree(c->u.name);
+ goto out;
+ }
+
+ /* sort by ->u.name length, longest first */
+ last = NULL;
+ iter = p->ocontexts[OCON_KDBUS];
+ while (iter != c) {
+ len2 = strlen(iter->u.name);
+ if (len > len2) {
+ if (l2)
+ l2->next = NULL;
+ c->next = iter;
+ if (last == NULL)
+ p->ocontexts[i] = c;
+ else
+ last->next = c;
+ break;
+ }
+ last = iter;
+ iter = iter->next;
+ }
+ break;
+ }
}
}
}
@@ -3147,6 +3190,19 @@ static int ocontext_write(struct policydb *p, struct policydb_compat_info *info,
if (rc)
return rc;
break;
+ case OCON_KDBUS:
+ len = strlen(c->u.name);
+ buf[0] = cpu_to_le32(len);
+ rc = put_entry(buf, sizeof(u32), 1, fp);
+ if (rc)
+ return rc;
+ rc = put_entry(c->u.name, len, 1, fp);
+ if (rc)
+ return rc;
+ rc = context_write(p, &c->context[0], fp);
+ if (rc)
+ return rc;
+ break;
}
}
}
diff --git a/security/selinux/ss/policydb.h b/security/selinux/ss/policydb.h
index 725d594..ee9c120 100644
--- a/security/selinux/ss/policydb.h
+++ b/security/selinux/ss/policydb.h
@@ -222,7 +222,8 @@ struct genfs {
#define OCON_NODE 4 /* nodes */
#define OCON_FSUSE 5 /* fs_use */
#define OCON_NODE6 6 /* IPv6 nodes */
-#define OCON_NUM 7
+#define OCON_KDBUS 7 /* kdbus names */
+#define OCON_NUM 8
/* The policy database */
struct policydb {
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index b7df12b..ada2d28 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -2536,6 +2536,44 @@ int security_genfs_sid(const char *fstype,
}
/**
+ * security_kdbus_sid - Obtain a SID for a kdbus name
+ * @name: kdbus name
+ * @sid: SID for the kdbus name
+ *
+ * Obtain a SID for the given kdbus service name. Returns zero on success,
+ * negative values on error.
+ */
+int security_kdbus_sid(const char *name, u32 *sid)
+{
+ int rc = 0;
+ struct ocontext *c;
+
+ read_lock(&policy_rwlock);
+
+ c = policydb.ocontexts[OCON_KDBUS];
+ while (c) {
+ if (strncmp(c->u.name, name, strlen(c->u.name)) == 0)
+ break;
+ c = c->next;
+ }
+
+ if (c) {
+ if (!c->sid[0]) {
+ rc = sidtab_context_to_sid(&sidtab,
+ &c->context[0], &c->sid[0]);
+ if (rc)
+ goto out;
+ }
+ *sid = c->sid[0];
+ } else
+ *sid = SECINITSID_UNLABELED;
+
+out:
+ read_unlock(&policy_rwlock);
+ return rc;
+}
+
+/**
* security_fs_use - Determine how to handle labeling for a filesystem.
* @sb: superblock in question
*/
^ permalink raw reply related [flat|nested] 8+ messages in thread* [RFC PATCH v2 5/5] selinux: introduce kdbus access controls
2015-10-05 20:41 [RFC PATCH v2 0/5] kdbus LSM/SELinux hooks Paul Moore
` (3 preceding siblings ...)
2015-10-05 20:41 ` [RFC PATCH v2 4/5] selinux: introduce kdbus names into the policy Paul Moore
@ 2015-10-05 20:41 ` Paul Moore
2015-10-06 18:55 ` Nicolas Iooss
4 siblings, 1 reply; 8+ messages in thread
From: Paul Moore @ 2015-10-05 20:41 UTC (permalink / raw)
To: linux-security-module; +Cc: linux-audit, selinux
Add the SELinux access control implementation for the new kdbus LSM
hooks using the new kdbus object class and the following permissions:
[NOTE: permissions below are based on kdbus code from Aug 2015]
* kdbus:impersonate
Send a different security label to kdbus peers.
* kdbus:fakecreds
Send different DAC credentials to kdbus peers.
* kdbus:fakepids
Send a different PID to kdbus peers.
* kdbus:owner
Act as a kdbus bus owner.
* kdbus:privileged
Act as a privileged endpoint.
* kdbus:activator
Act as a kdbus activator.
* kdbus:monitor
Act as a kdbus monitor.
* kdbus:policy_holder
Act as a kdbus policy holder.
* kdbus:connect
Create a new kdbus connection.
* kdbus:own
Own a kdbus service name.
* kdbus:talk
Talk between two kdbus endpoints.
* kdbus:see
See another kdbus endpoint.
* kdbus:see_name
See a kdbus service name.
* kdbus:see_notification
See a kdbus notification.
Signed-off-by: Paul Moore <pmoore@redhat.com>
---
ChangeLog:
- v2
* Add the selinux_kdbus_init_inode() hook
* Add some very basic info on the permissions to the description
* Add kdbus service name auditing in the AVC records
- v1
* Initial draft
---
security/selinux/hooks.c | 152 +++++++++++++++++++++++++++++++++++
security/selinux/include/classmap.h | 4 +
2 files changed, 154 insertions(+), 2 deletions(-)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 4d7e602..29341dd 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -9,8 +9,10 @@
* James Morris <jmorris@redhat.com>
*
* Copyright (C) 2001,2002 Networks Associates Technology, Inc.
- * Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
- * Eric Paris <eparis@redhat.com>
+ * Copyright (C) 2003-2008,2015 Red Hat, Inc.
+ * James Morris <jmorris@redhat.com>
+ * Eric Paris <eparis@redhat.com>
+ * Paul Moore <paul@paul-moore.com>
* Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
* <dgoeddel@trustedcs.com>
* Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P.
@@ -1987,6 +1989,143 @@ static int selinux_binder_transfer_file(struct task_struct *from,
&ad);
}
+static int selinux_kdbus_conn_new(const struct cred *creds,
+ const struct kdbus_creds *fake_creds,
+ const struct kdbus_pids *fake_pids,
+ const char *fake_seclabel,
+ bool owner, bool privileged,
+ bool is_activator, bool is_monitor,
+ bool is_policy_holder)
+{
+ int rc;
+ u32 tsid = current_sid();
+ u32 av = KDBUS__CONNECT;
+
+ if (fake_creds)
+ av |= KDBUS__FAKECREDS;
+ if (fake_pids)
+ av |= KDBUS__FAKEPIDS;
+ if (owner)
+ av |= KDBUS__OWNER;
+ if (privileged)
+ av |= KDBUS__PRIVILEGED;
+ if (is_activator)
+ av |= KDBUS__ACTIVATOR;
+ if (is_monitor)
+ av |= KDBUS__MONITOR;
+ if (is_policy_holder)
+ av |= KDBUS__POLICY_HOLDER;
+
+ rc = avc_has_perm(tsid, cred_sid(creds), SECCLASS_KDBUS, av, NULL);
+ if (rc)
+ return rc;
+
+ if (fake_seclabel) {
+ u32 sid;
+ if (security_context_to_sid(fake_seclabel,
+ strlen(fake_seclabel),
+ &sid, GFP_KERNEL))
+ return -EINVAL;
+
+ rc = avc_has_perm(tsid, sid,
+ SECCLASS_KDBUS, KDBUS__IMPERSONATE, NULL);
+ }
+
+ return rc;
+}
+
+static int selinux_kdbus_own_name(const struct cred *creds, const char *name)
+{
+ int rc;
+ u32 name_sid;
+ struct common_audit_data ad;
+
+ rc = security_kdbus_sid(name, &name_sid);
+ if (rc)
+ return rc;
+
+ ad.type = LSM_AUDIT_DATA_KDBUS;
+ ad.u.kdbus_name = name;
+
+ return avc_has_perm(cred_sid(creds), name_sid,
+ SECCLASS_KDBUS, KDBUS__OWN, &ad);
+}
+
+static int selinux_kdbus_conn_talk(const struct cred *creds,
+ const struct cred *creds_to)
+{
+ return avc_has_perm(cred_sid(creds), cred_sid(creds_to),
+ SECCLASS_KDBUS, KDBUS__TALK, NULL);
+}
+
+static int selinux_kdbus_conn_see(const struct cred *creds,
+ const struct cred *creds_whom)
+{
+ return avc_has_perm(cred_sid(creds), cred_sid(creds_whom),
+ SECCLASS_KDBUS, KDBUS__SEE, NULL);
+}
+
+static int selinux_kdbus_conn_see_name(const struct cred *creds,
+ const char *name)
+{
+ int rc;
+ u32 name_sid;
+ struct common_audit_data ad;
+
+ rc = security_kdbus_sid(name, &name_sid);
+ if (rc)
+ return rc;
+
+ ad.type = LSM_AUDIT_DATA_KDBUS;
+ ad.u.kdbus_name = name;
+
+ return avc_has_perm(cred_sid(creds), name_sid,
+ SECCLASS_KDBUS, KDBUS__SEE_NAME, &ad);
+}
+
+static int selinux_kdbus_conn_see_notification(const struct cred *creds)
+{
+ return avc_has_perm(SECINITSID_KERNEL, cred_sid(creds),
+ SECCLASS_KDBUS, KDBUS__SEE_NOTIFICATION, NULL);
+}
+
+static int selinux_kdbus_proc_permission(const struct cred *creds,
+ struct pid *pid)
+{
+ int rc;
+ struct task_struct *task;
+
+ rcu_read_lock();
+ task = pid_task(pid, PIDTYPE_PID);
+ rc = avc_has_perm(cred_sid(creds), task_sid(task),
+ SECCLASS_PROCESS, PROCESS__GETATTR, NULL);
+ rcu_read_unlock();
+
+ return rc;
+}
+
+static int selinux_kdbus_init_inode(struct inode *inode,
+ const struct cred *creds)
+{
+ struct inode_security_struct *isec = inode->i_security;
+ u32 sid = cred_sid(creds);
+
+ /* XXX - this is very simple, e.g. no transitions, no special object
+ * class, etc. since this inode is basically an IPC socket ...
+ * however, is this too simple? do we want transitions? if we
+ * do, we should do the transition in kdbus_node_init() and not
+ * here so that endpoint is labeled correctly and not just this
+ * inode */
+
+ isec->inode = inode;
+ isec->task_sid = sid;
+ isec->sid = sid;
+ isec->sclass = SECCLASS_FILE;
+ isec->initialized = 1;
+
+ return 0;
+}
+
static int selinux_ptrace_access_check(struct task_struct *child,
unsigned int mode)
{
@@ -5888,6 +6027,15 @@ static struct security_operations selinux_ops = {
.binder_transfer_binder = selinux_binder_transfer_binder,
.binder_transfer_file = selinux_binder_transfer_file,
+ .kdbus_conn_new = selinux_kdbus_conn_new,
+ .kdbus_own_name = selinux_kdbus_own_name,
+ .kdbus_conn_talk = selinux_kdbus_conn_talk,
+ .kdbus_conn_see_name = selinux_kdbus_conn_see_name,
+ .kdbus_conn_see = selinux_kdbus_conn_see,
+ .kdbus_conn_see_notification = selinux_kdbus_conn_see_notification,
+ .kdbus_proc_permission = selinux_kdbus_proc_permission,
+ .kdbus_init_inode = selinux_kdbus_init_inode,
+
.ptrace_access_check = selinux_ptrace_access_check,
.ptrace_traceme = selinux_ptrace_traceme,
.capget = selinux_capget,
diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h
index eccd61b..31e4435 100644
--- a/security/selinux/include/classmap.h
+++ b/security/selinux/include/classmap.h
@@ -153,5 +153,9 @@ struct security_class_mapping secclass_map[] = {
{ COMMON_SOCK_PERMS, "attach_queue", NULL } },
{ "binder", { "impersonate", "call", "set_context_mgr", "transfer",
NULL } },
+ { "kdbus", { "impersonate", "fakecreds", "fakepids", "owner",
+ "privileged", "activator", "monitor", "policy_holder",
+ "connect", "own", "talk", "see", "see_name",
+ "see_notification" } },
{ NULL }
};
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [RFC PATCH v2 5/5] selinux: introduce kdbus access controls
2015-10-05 20:41 ` [RFC PATCH v2 5/5] selinux: introduce kdbus access controls Paul Moore
@ 2015-10-06 18:55 ` Nicolas Iooss
2015-10-06 22:20 ` Paul Moore
0 siblings, 1 reply; 8+ messages in thread
From: Nicolas Iooss @ 2015-10-06 18:55 UTC (permalink / raw)
To: Paul Moore, linux-security-module-u79uwXL29TY76Z2rM5mHXA
Cc: linux-audit-H+wXaHxf7aLQT0dZR+AlfA,
selinux-+05T5uksL2qpZYMLLGbcSA
On 10/05/2015 10:41 PM, Paul Moore wrote:
> Add the SELinux access control implementation for the new kdbus LSM
> hooks using the new kdbus object class and the following permissions:
>
[[SNIP]]
> diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h
> index eccd61b..31e4435 100644
> --- a/security/selinux/include/classmap.h
> +++ b/security/selinux/include/classmap.h
> @@ -153,5 +153,9 @@ struct security_class_mapping secclass_map[] = {
> { COMMON_SOCK_PERMS, "attach_queue", NULL } },
> { "binder", { "impersonate", "call", "set_context_mgr", "transfer",
> NULL } },
> + { "kdbus", { "impersonate", "fakecreds", "fakepids", "owner",
> + "privileged", "activator", "monitor", "policy_holder",
> + "connect", "own", "talk", "see", "see_name",
> + "see_notification" } },
> { NULL }
> };
Hello,
Out of curiosity, why is the new list of permissions not
NULL-terminated? As far as I can tell, as the field "perms" of struct
security_class_mapping is a fixed-size vector, it doesn't matter here
(the C compiler would always pad with NULL pointers), but then I am
wondering why all the other lists of perms are NULL-terminated in
classmap.h.
Thanks,
Nicolas
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^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [RFC PATCH v2 5/5] selinux: introduce kdbus access controls
2015-10-06 18:55 ` Nicolas Iooss
@ 2015-10-06 22:20 ` Paul Moore
0 siblings, 0 replies; 8+ messages in thread
From: Paul Moore @ 2015-10-06 22:20 UTC (permalink / raw)
To: Nicolas Iooss; +Cc: linux-security-module, linux-audit, selinux
On Tuesday, October 06, 2015 08:55:33 PM Nicolas Iooss wrote:
> On 10/05/2015 10:41 PM, Paul Moore wrote:
> > Add the SELinux access control implementation for the new kdbus LSM
>
> > hooks using the new kdbus object class and the following permissions:
> [[SNIP]]
>
> > diff --git a/security/selinux/include/classmap.h
> > b/security/selinux/include/classmap.h index eccd61b..31e4435 100644
> > --- a/security/selinux/include/classmap.h
> > +++ b/security/selinux/include/classmap.h
> > @@ -153,5 +153,9 @@ struct security_class_mapping secclass_map[] = {
> >
> > { COMMON_SOCK_PERMS, "attach_queue", NULL } },
> >
> > { "binder", { "impersonate", "call", "set_context_mgr", "transfer",
> >
> > NULL } },
> >
> > + { "kdbus", { "impersonate", "fakecreds", "fakepids", "owner",
> > + "privileged", "activator", "monitor", "policy_holder",
> > + "connect", "own", "talk", "see", "see_name",
> > + "see_notification" } },
> >
> > { NULL }
> >
> > };
>
> Hello,
> Out of curiosity, why is the new list of permissions not
> NULL-terminated?
Honest answer: I forgot :)
These patches are still "RFC quality" which means I'm emphasizing getting the
patches posted quickly (hardy har har) and not putting the code through as
much testing and scrutiny as I usually do. The idea right now is to get
feedback about the hooks and the individual LSM implementations.
Regardless, thanks for catching the missing terminator, the fix will be in the
next draft of the patches.
--
paul moore
security @ redhat
^ permalink raw reply [flat|nested] 8+ messages in thread