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* [PATCH v7 14/28] IMA: Change internal interfaces to use lsmblobs
From: Casey Schaufler @ 2019-08-07 19:43 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds
In-Reply-To: <20190807194410.9762-1-casey@schaufler-ca.com>

The IMA interfaces ima_get_action() and ima_match_policy()
call LSM functions that use lsmblobs. Change the IMA functions
to pass the lsmblob to be compatible with the LSM functions.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 security/integrity/ima/ima.h          | 10 ++++++----
 security/integrity/ima/ima_api.c      |  9 +++++----
 security/integrity/ima/ima_appraise.c |  4 +---
 security/integrity/ima/ima_main.c     | 27 +++++++++++----------------
 security/integrity/ima/ima_policy.c   | 12 ++++++------
 5 files changed, 29 insertions(+), 33 deletions(-)

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 5a337239d9e4..73b3b15dec5c 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -192,8 +192,9 @@ enum ima_hooks {
 };
 
 /* LIM API function definitions */
-int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
-		   int mask, enum ima_hooks func, int *pcr);
+int ima_get_action(struct inode *inode, const struct cred *cred,
+		   struct lsmblob *blob, int mask, enum ima_hooks func,
+		   int *pcr);
 int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func);
 int ima_collect_measurement(struct integrity_iint_cache *iint,
 			    struct file *file, void *buf, loff_t size,
@@ -213,8 +214,9 @@ void ima_free_template_entry(struct ima_template_entry *entry);
 const char *ima_d_path(const struct path *path, char **pathbuf, char *filename);
 
 /* IMA policy related functions */
-int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
-		     enum ima_hooks func, int mask, int flags, int *pcr);
+int ima_match_policy(struct inode *inode, const struct cred *cred,
+		     struct lsmblob *blob, enum ima_hooks func, int mask,
+		     int flags, int *pcr);
 void ima_init_policy(void);
 void ima_update_policy(void);
 void ima_update_policy_flag(void);
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index c7505fb122d4..94b2a4840d81 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -159,7 +159,7 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
  * ima_get_action - appraise & measure decision based on policy.
  * @inode: pointer to inode to measure
  * @cred: pointer to credentials structure to validate
- * @secid: secid of the task being validated
+ * @blob: LSM data of the task being validated
  * @mask: contains the permission mask (MAY_READ, MAY_WRITE, MAY_EXEC,
  *        MAY_APPEND)
  * @func: caller identifier
@@ -175,14 +175,15 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
  * Returns IMA_MEASURE, IMA_APPRAISE mask.
  *
  */
-int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
-		   int mask, enum ima_hooks func, int *pcr)
+int ima_get_action(struct inode *inode, const struct cred *cred,
+		   struct lsmblob *blob, int mask, enum ima_hooks func,
+		   int *pcr)
 {
 	int flags = IMA_MEASURE | IMA_AUDIT | IMA_APPRAISE | IMA_HASH;
 
 	flags &= ima_policy_flag;
 
-	return ima_match_policy(inode, cred, secid, func, mask, flags, pcr);
+	return ima_match_policy(inode, cred, blob, func, mask, flags, pcr);
 }
 
 /*
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 85c7692fc4a3..3ff7aae81829 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -50,15 +50,13 @@ bool is_ima_appraise_enabled(void)
  */
 int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func)
 {
-	u32 secid;
 	struct lsmblob blob;
 
 	if (!ima_appraise)
 		return 0;
 
 	security_task_getsecid(current, &blob);
-	lsmblob_secid(&blob, &secid);
-	return ima_match_policy(inode, current_cred(), secid, func, mask,
+	return ima_match_policy(inode, current_cred(), &blob, func, mask,
 				IMA_APPRAISE | IMA_HASH, NULL);
 }
 
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 1afb75a893af..0588dd9a88db 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -169,8 +169,8 @@ void ima_file_free(struct file *file)
 }
 
 static int process_measurement(struct file *file, const struct cred *cred,
-			       u32 secid, char *buf, loff_t size, int mask,
-			       enum ima_hooks func)
+			       struct lsmblob *blob, char *buf, loff_t size,
+			       int mask, enum ima_hooks func)
 {
 	struct inode *inode = file_inode(file);
 	struct integrity_iint_cache *iint = NULL;
@@ -192,7 +192,7 @@ static int process_measurement(struct file *file, const struct cred *cred,
 	 * bitmask based on the appraise/audit/measurement policy.
 	 * Included is the appraise submask.
 	 */
-	action = ima_get_action(inode, cred, secid, mask, func, &pcr);
+	action = ima_get_action(inode, cred, blob, mask, func, &pcr);
 	violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) &&
 			   (ima_policy_flag & IMA_MEASURE));
 	if (!action && !violation_check)
@@ -339,8 +339,7 @@ int ima_file_mmap(struct file *file, unsigned long prot)
 
 	if (file && (prot & PROT_EXEC)) {
 		security_task_getsecid(current, &blob);
-		/* scaffolding - until process_measurement changes */
-		return process_measurement(file, current_cred(), blob.secid[0],
+		return process_measurement(file, current_cred(), &blob,
 					   NULL, 0, MAY_EXEC, MMAP_CHECK);
 	}
 
@@ -366,16 +365,14 @@ int ima_bprm_check(struct linux_binprm *bprm)
 	struct lsmblob blob;
 
 	security_task_getsecid(current, &blob);
-	/* scaffolding until process_measurement changes */
-	ret = process_measurement(bprm->file, current_cred(), blob.secid[0],
-				  NULL, 0, MAY_EXEC, BPRM_CHECK);
+	ret = process_measurement(bprm->file, current_cred(), &blob, NULL, 0,
+				  MAY_EXEC, BPRM_CHECK);
 	if (ret)
 		return ret;
 
 	security_cred_getsecid(bprm->cred, &blob);
-	/* scaffolding until process_measurement changes */
-	return process_measurement(bprm->file, bprm->cred, blob.secid[0],
-				   NULL, 0, MAY_EXEC, CREDS_CHECK);
+	return process_measurement(bprm->file, bprm->cred, &blob, NULL, 0,
+				   MAY_EXEC, CREDS_CHECK);
 }
 
 /**
@@ -393,8 +390,7 @@ int ima_file_check(struct file *file, int mask)
 	struct lsmblob blob;
 
 	security_task_getsecid(current, &blob);
-	/* scaffolding until process_measurement changes */
-	return process_measurement(file, current_cred(), blob.secid[0], NULL, 0,
+	return process_measurement(file, current_cred(), &blob, NULL, 0,
 				   mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
 					   MAY_APPEND), FILE_CHECK);
 }
@@ -526,9 +522,8 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
 
 	func = read_idmap[read_id] ?: FILE_CHECK;
 	security_task_getsecid(current, &blob);
-	/* scaffolding until process_measurement changes */
-	return process_measurement(file, current_cred(), blob.secid[0], buf,
-				   size, MAY_READ, func);
+	return process_measurement(file, current_cred(), &blob, buf, size,
+				   MAY_READ, func);
 }
 
 /**
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 92ee3d984c73..dbad256aa7b4 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -286,7 +286,7 @@ static void ima_lsm_update_rules(void)
  * Returns true on rule match, false on failure.
  */
 static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
-			    const struct cred *cred, u32 secid,
+			    const struct cred *cred, struct lsmblob *blob,
 			    enum ima_hooks func, int mask)
 {
 	int i;
@@ -345,7 +345,6 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 		case LSM_SUBJ_USER:
 		case LSM_SUBJ_ROLE:
 		case LSM_SUBJ_TYPE:
-			lsmblob_init(&blob, secid);
 			rc = security_filter_rule_match(&blob,
 							rule->lsm[i].type,
 							Audit_equal,
@@ -394,7 +393,7 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
  * @inode: pointer to an inode for which the policy decision is being made
  * @cred: pointer to a credentials structure for which the policy decision is
  *        being made
- * @secid: LSM secid of the task to be validated
+ * @blob: LSM data of the task to be validated
  * @func: IMA hook identifier
  * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
  * @pcr: set the pcr to extend
@@ -406,8 +405,9 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
  * list when walking it.  Reads are many orders of magnitude more numerous
  * than writes so ima_match_policy() is classical RCU candidate.
  */
-int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
-		     enum ima_hooks func, int mask, int flags, int *pcr)
+int ima_match_policy(struct inode *inode, const struct cred *cred,
+		     struct lsmblob *blob, enum ima_hooks func, int mask,
+		     int flags, int *pcr)
 {
 	struct ima_rule_entry *entry;
 	int action = 0, actmask = flags | (flags << 1);
@@ -418,7 +418,7 @@ int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
 		if (!(entry->action & actmask))
 			continue;
 
-		if (!ima_match_rules(entry, inode, cred, secid, func, mask))
+		if (!ima_match_rules(entry, inode, cred, blob, func, mask))
 			continue;
 
 		action |= entry->flags & IMA_ACTION_FLAGS;
-- 
2.20.1


^ permalink raw reply related

* [PATCH v7 13/28] LSM: Use lsmblob in security_cred_getsecid
From: Casey Schaufler @ 2019-08-07 19:43 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds
In-Reply-To: <20190807194410.9762-1-casey@schaufler-ca.com>

Change the security_cred_getsecid() interface to fill in a
lsmblob instead of a u32 secid. The associated data elements
in the audit sub-system are changed from a secid to a lsmblob
to accommodate multiple possible LSM audit users.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/security.h          |  2 +-
 kernel/audit.c                    | 14 +++++-------
 kernel/audit.h                    |  5 +++--
 kernel/auditsc.c                  | 37 +++++++++++--------------------
 security/integrity/ima/ima_main.c |  8 +++----
 security/security.c               | 12 +++++++---
 6 files changed, 36 insertions(+), 42 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index 2d81cac418e3..d310fa3942ce 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -387,7 +387,7 @@ int security_cred_alloc_blank(struct cred *cred, gfp_t gfp);
 void security_cred_free(struct cred *cred);
 int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp);
 void security_transfer_creds(struct cred *new, const struct cred *old);
-void security_cred_getsecid(const struct cred *c, u32 *secid);
+void security_cred_getsecid(const struct cred *c, struct lsmblob *blob);
 int security_kernel_act_as(struct cred *new, struct lsmblob *blob);
 int security_kernel_create_files_as(struct cred *new, struct inode *inode);
 int security_kernel_module_request(char *kmod_name);
diff --git a/kernel/audit.c b/kernel/audit.c
index a0205f3c23c7..1b51e907f131 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -137,7 +137,7 @@ static u32	audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
 /* The identity of the user shutting down the audit system. */
 kuid_t		audit_sig_uid = INVALID_UID;
 pid_t		audit_sig_pid = -1;
-u32		audit_sig_sid = 0;
+struct lsmblob	audit_sig_lsm;
 
 /* Records can be lost in several ways:
    0) [suppressed in audit_alloc]
@@ -1429,23 +1429,21 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 	}
 	case AUDIT_SIGNAL_INFO:
 		len = 0;
-		if (audit_sig_sid) {
-			struct lsmblob blob;
-
-			lsmblob_init(&blob, audit_sig_sid);
-			err = security_secid_to_secctx(&blob, &ctx, &len);
+		if (lsmblob_is_set(&audit_sig_lsm)) {
+			err = security_secid_to_secctx(&audit_sig_lsm, &ctx,
+						       &len);
 			if (err)
 				return err;
 		}
 		sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
 		if (!sig_data) {
-			if (audit_sig_sid)
+			if (lsmblob_is_set(&audit_sig_lsm))
 				security_release_secctx(ctx, len);
 			return -ENOMEM;
 		}
 		sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
 		sig_data->pid = audit_sig_pid;
-		if (audit_sig_sid) {
+		if (lsmblob_is_set(&audit_sig_lsm)) {
 			memcpy(sig_data->ctx, ctx, len);
 			security_release_secctx(ctx, len);
 		}
diff --git a/kernel/audit.h b/kernel/audit.h
index 958d5b8fc1b3..29e29c6f4afb 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -22,6 +22,7 @@
 #include <linux/fs.h>
 #include <linux/audit.h>
 #include <linux/skbuff.h>
+#include <linux/security.h>
 #include <uapi/linux/mqueue.h>
 #include <linux/tty.h>
 
@@ -147,7 +148,7 @@ struct audit_context {
 	kuid_t		    target_auid;
 	kuid_t		    target_uid;
 	unsigned int	    target_sessionid;
-	u32		    target_sid;
+	struct lsmblob   target_lsm;
 	char		    target_comm[TASK_COMM_LEN];
 
 	struct audit_tree_refs *trees, *first_trees;
@@ -338,7 +339,7 @@ extern char *audit_unpack_string(void **bufp, size_t *remain, size_t len);
 
 extern pid_t audit_sig_pid;
 extern kuid_t audit_sig_uid;
-extern u32 audit_sig_sid;
+extern struct lsmblob audit_sig_lsm;
 
 extern int audit_filter(int msgtype, unsigned int listtype);
 
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 54797c0fc3b7..c7aa39bda5cc 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -112,7 +112,7 @@ struct audit_aux_data_pids {
 	kuid_t			target_auid[AUDIT_AUX_PIDS];
 	kuid_t			target_uid[AUDIT_AUX_PIDS];
 	unsigned int		target_sessionid[AUDIT_AUX_PIDS];
-	u32			target_sid[AUDIT_AUX_PIDS];
+	struct lsmblob	target_lsm[AUDIT_AUX_PIDS];
 	char 			target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN];
 	int			pid_count;
 };
@@ -938,14 +938,14 @@ static inline void audit_free_context(struct audit_context *context)
 }
 
 static int audit_log_pid_context(struct audit_context *context, pid_t pid,
-				 kuid_t auid, kuid_t uid, unsigned int sessionid,
-				 u32 sid, char *comm)
+				 kuid_t auid, kuid_t uid,
+				 unsigned int sessionid,
+				 struct lsmblob *blob, char *comm)
 {
 	struct audit_buffer *ab;
 	char *ctx = NULL;
 	u32 len;
 	int rc = 0;
-	struct lsmblob blob;
 
 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
 	if (!ab)
@@ -954,9 +954,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
 	audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid,
 			 from_kuid(&init_user_ns, auid),
 			 from_kuid(&init_user_ns, uid), sessionid);
-	if (sid) {
-		lsmblob_init(&blob, sid);
-		if (security_secid_to_secctx(&blob, &ctx, &len)) {
+	if (lsmblob_is_set(blob)) {
+		if (security_secid_to_secctx(blob, &ctx, &len)) {
 			audit_log_format(ab, " obj=(none)");
 			rc = 1;
 		} else {
@@ -1527,7 +1526,7 @@ static void audit_log_exit(void)
 						  axs->target_auid[i],
 						  axs->target_uid[i],
 						  axs->target_sessionid[i],
-						  axs->target_sid[i],
+						  &axs->target_lsm[i],
 						  axs->target_comm[i]))
 				call_panic = 1;
 	}
@@ -1536,7 +1535,7 @@ static void audit_log_exit(void)
 	    audit_log_pid_context(context, context->target_pid,
 				  context->target_auid, context->target_uid,
 				  context->target_sessionid,
-				  context->target_sid, context->target_comm))
+				  &context->target_lsm, context->target_comm))
 			call_panic = 1;
 
 	if (context->pwd.dentry && context->pwd.mnt) {
@@ -1713,7 +1712,7 @@ void __audit_syscall_exit(int success, long return_code)
 	context->aux = NULL;
 	context->aux_pids = NULL;
 	context->target_pid = 0;
-	context->target_sid = 0;
+	lsmblob_init(&context->target_lsm, 0);
 	context->sockaddr_len = 0;
 	context->type = 0;
 	context->fds[0] = -1;
@@ -2367,15 +2366,12 @@ int __audit_sockaddr(int len, void *a)
 void __audit_ptrace(struct task_struct *t)
 {
 	struct audit_context *context = audit_context();
-	struct lsmblob blob;
 
 	context->target_pid = task_tgid_nr(t);
 	context->target_auid = audit_get_loginuid(t);
 	context->target_uid = task_uid(t);
 	context->target_sessionid = audit_get_sessionid(t);
-	security_task_getsecid(t, &blob);
-	/* scaffolding - until target_sid is converted */
-	context->target_sid = blob.secid[0];
+	security_task_getsecid(t, &context->target_lsm);
 	memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
 }
 
@@ -2392,7 +2388,6 @@ int audit_signal_info(int sig, struct task_struct *t)
 	struct audit_aux_data_pids *axp;
 	struct audit_context *ctx = audit_context();
 	kuid_t uid = current_uid(), auid, t_uid = task_uid(t);
-	struct lsmblob blob;
 
 	if (auditd_test_task(t) &&
 	    (sig == SIGTERM || sig == SIGHUP ||
@@ -2403,9 +2398,7 @@ int audit_signal_info(int sig, struct task_struct *t)
 			audit_sig_uid = auid;
 		else
 			audit_sig_uid = uid;
-		security_task_getsecid(current, &blob);
-		/* scaffolding until audit_sig_sid is converted */
-		audit_sig_sid = blob.secid[0];
+		security_task_getsecid(current, &audit_sig_lsm);
 	}
 
 	if (!audit_signals || audit_dummy_context())
@@ -2418,9 +2411,7 @@ int audit_signal_info(int sig, struct task_struct *t)
 		ctx->target_auid = audit_get_loginuid(t);
 		ctx->target_uid = t_uid;
 		ctx->target_sessionid = audit_get_sessionid(t);
-		security_task_getsecid(t, &blob);
-		/* scaffolding until target_sid is converted */
-		ctx->target_sid = blob.secid[0];
+		security_task_getsecid(t, &ctx->target_lsm);
 		memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
 		return 0;
 	}
@@ -2441,9 +2432,7 @@ int audit_signal_info(int sig, struct task_struct *t)
 	axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
 	axp->target_uid[axp->pid_count] = t_uid;
 	axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
-	security_task_getsecid(t, &blob);
-	/* scaffolding until target_sid is converted */
-	axp->target_sid[axp->pid_count] = blob.secid[0];
+	security_task_getsecid(t, &axp->target_lsm[axp->pid_count]);
 	memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
 	axp->pid_count++;
 
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index fefa848cf0c7..1afb75a893af 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -363,7 +363,6 @@ int ima_file_mmap(struct file *file, unsigned long prot)
 int ima_bprm_check(struct linux_binprm *bprm)
 {
 	int ret;
-	u32 secid;
 	struct lsmblob blob;
 
 	security_task_getsecid(current, &blob);
@@ -373,9 +372,10 @@ int ima_bprm_check(struct linux_binprm *bprm)
 	if (ret)
 		return ret;
 
-	security_cred_getsecid(bprm->cred, &secid);
-	return process_measurement(bprm->file, bprm->cred, secid, NULL, 0,
-				   MAY_EXEC, CREDS_CHECK);
+	security_cred_getsecid(bprm->cred, &blob);
+	/* scaffolding until process_measurement changes */
+	return process_measurement(bprm->file, bprm->cred, blob.secid[0],
+				   NULL, 0, MAY_EXEC, CREDS_CHECK);
 }
 
 /**
diff --git a/security/security.c b/security/security.c
index 745e8791b6e3..8927508b2142 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1627,10 +1627,16 @@ void security_transfer_creds(struct cred *new, const struct cred *old)
 	call_void_hook(cred_transfer, new, old);
 }
 
-void security_cred_getsecid(const struct cred *c, u32 *secid)
+void security_cred_getsecid(const struct cred *c, struct lsmblob *blob)
 {
-	*secid = 0;
-	call_void_hook(cred_getsecid, c, secid);
+	struct security_hook_list *hp;
+
+	lsmblob_init(blob, 0);
+	hlist_for_each_entry(hp, &security_hook_heads.cred_getsecid, list) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		hp->hook.cred_getsecid(c, &blob->secid[hp->lsmid->slot]);
+	}
 }
 EXPORT_SYMBOL(security_cred_getsecid);
 
-- 
2.20.1


^ permalink raw reply related

* [PATCH v7 12/28] LSM: Use lsmblob in security_inode_getsecid
From: Casey Schaufler @ 2019-08-07 19:43 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds
In-Reply-To: <20190807194410.9762-1-casey@schaufler-ca.com>

Change the security_inode_getsecid() interface to fill in a
lsmblob structure instead of a u32 secid. This allows for its
callers to gather data from all registered LSMs. Data is provided
for IMA and audit.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/security.h            |  7 ++++---
 kernel/auditsc.c                    |  6 +++++-
 security/integrity/ima/ima_policy.c |  4 +---
 security/security.c                 | 11 +++++++++--
 4 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index cfd7cf4b0be9..2d81cac418e3 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -362,7 +362,7 @@ int security_inode_killpriv(struct dentry *dentry);
 int security_inode_getsecurity(struct inode *inode, const char *name, void **buffer, bool alloc);
 int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags);
 int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size);
-void security_inode_getsecid(struct inode *inode, u32 *secid);
+void security_inode_getsecid(struct inode *inode, struct lsmblob *blob);
 int security_inode_copy_up(struct dentry *src, struct cred **new);
 int security_inode_copy_up_xattr(const char *name);
 int security_file_permission(struct file *file, int mask);
@@ -858,9 +858,10 @@ static inline int security_inode_listsecurity(struct inode *inode, char *buffer,
 	return 0;
 }
 
-static inline void security_inode_getsecid(struct inode *inode, u32 *secid)
+static inline void security_inode_getsecid(struct inode *inode,
+					   struct lsmblob *blob)
 {
-	*secid = 0;
+	lsmblob_init(blob, 0);
 }
 
 static inline int security_inode_copy_up(struct dentry *src, struct cred **new)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 7112fe31684d..54797c0fc3b7 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1910,13 +1910,17 @@ static inline int audit_copy_fcaps(struct audit_names *name,
 void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
 		      struct inode *inode, unsigned int flags)
 {
+	struct lsmblob blob;
+
 	name->ino   = inode->i_ino;
 	name->dev   = inode->i_sb->s_dev;
 	name->mode  = inode->i_mode;
 	name->uid   = inode->i_uid;
 	name->gid   = inode->i_gid;
 	name->rdev  = inode->i_rdev;
-	security_inode_getsecid(inode, &name->osid);
+	security_inode_getsecid(inode, &blob);
+	/* scaffolding until osid is updated */
+	name->osid = blob.secid[0];
 	if (flags & AUDIT_INODE_NOEVAL) {
 		name->fcap_ver = -1;
 		return;
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index e7b8ce942950..92ee3d984c73 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -326,7 +326,6 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 		return false;
 	for (i = 0; i < MAX_LSM_RULES; i++) {
 		int rc = 0;
-		u32 osid;
 		struct lsmblob blob;
 		int retried = 0;
 
@@ -337,8 +336,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 		case LSM_OBJ_USER:
 		case LSM_OBJ_ROLE:
 		case LSM_OBJ_TYPE:
-			security_inode_getsecid(inode, &osid);
-			lsmblob_init(&blob, osid);
+			security_inode_getsecid(inode, &blob);
 			rc = security_filter_rule_match(&blob,
 							rule->lsm[i].type,
 							Audit_equal,
diff --git a/security/security.c b/security/security.c
index 43076ae0373f..745e8791b6e3 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1404,9 +1404,16 @@ int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer
 }
 EXPORT_SYMBOL(security_inode_listsecurity);
 
-void security_inode_getsecid(struct inode *inode, u32 *secid)
+void security_inode_getsecid(struct inode *inode, struct lsmblob *blob)
 {
-	call_void_hook(inode_getsecid, inode, secid);
+	struct security_hook_list *hp;
+
+	lsmblob_init(blob, 0);
+	hlist_for_each_entry(hp, &security_hook_heads.inode_getsecid, list) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		hp->hook.inode_getsecid(inode, &blob->secid[hp->lsmid->slot]);
+	}
 }
 
 int security_inode_copy_up(struct dentry *src, struct cred **new)
-- 
2.20.1


^ permalink raw reply related

* [PATCH v7 10/28] LSM: Use lsmblob in security_ipc_getsecid
From: Casey Schaufler @ 2019-08-07 19:43 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds
In-Reply-To: <20190807194410.9762-1-casey@schaufler-ca.com>

There may be more than one LSM that provides IPC data
for auditing. Change security_ipc_getsecid() to fill in
a lsmblob structure instead of the u32 secid. The
audit data structure containing the secid will be updated
later, so there is a bit of scaffolding here.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/security.h |  7 ++++---
 kernel/auditsc.c         |  5 ++++-
 security/security.c      | 12 +++++++++---
 3 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index 7b4667cc4930..41dc3053094e 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -417,7 +417,7 @@ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3,
 			unsigned long arg4, unsigned long arg5);
 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);
+void security_ipc_getsecid(struct kern_ipc_perm *ipcp, struct lsmblob *blob);
 int security_msg_msg_alloc(struct msg_msg *msg);
 void security_msg_msg_free(struct msg_msg *msg);
 int security_msg_queue_alloc(struct kern_ipc_perm *msq);
@@ -1102,9 +1102,10 @@ static inline int security_ipc_permission(struct kern_ipc_perm *ipcp,
 	return 0;
 }
 
-static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
+static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp,
+					 struct lsmblob *blob)
 {
-	*secid = 0;
+	lsmblob_init(blob, 0);
 }
 
 static inline int security_msg_msg_alloc(struct msg_msg *msg)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index d31914088a82..148733ec3c72 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2268,11 +2268,14 @@ void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
 void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
 {
 	struct audit_context *context = audit_context();
+	struct lsmblob blob;
 	context->ipc.uid = ipcp->uid;
 	context->ipc.gid = ipcp->gid;
 	context->ipc.mode = ipcp->mode;
 	context->ipc.has_perm = 0;
-	security_ipc_getsecid(ipcp, &context->ipc.osid);
+	security_ipc_getsecid(ipcp, &blob);
+	/* scaffolding on the [0] - change "osid" to a lsmblob */
+	context->ipc.osid = blob.secid[0];
 	context->type = AUDIT_IPC;
 }
 
diff --git a/security/security.c b/security/security.c
index 837c3c6b6e7c..b4789c31e532 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1795,10 +1795,16 @@ int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
 	return call_int_hook(ipc_permission, 0, ipcp, flag);
 }
 
-void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
+void security_ipc_getsecid(struct kern_ipc_perm *ipcp, struct lsmblob *blob)
 {
-	*secid = 0;
-	call_void_hook(ipc_getsecid, ipcp, secid);
+	struct security_hook_list *hp;
+
+	lsmblob_init(blob, 0);
+	hlist_for_each_entry(hp, &security_hook_heads.ipc_getsecid, list) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		hp->hook.ipc_getsecid(ipcp, &blob->secid[hp->lsmid->slot]);
+	}
 }
 
 int security_msg_msg_alloc(struct msg_msg *msg)
-- 
2.20.1


^ permalink raw reply related

* [PATCH v7 11/28] LSM: Use lsmblob in security_task_getsecid
From: Casey Schaufler @ 2019-08-07 19:43 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds
In-Reply-To: <20190807194410.9762-1-casey@schaufler-ca.com>

Change the security_task_getsecid() interface to fill in
a lsmblob structure instead of a u32 secid in support of
LSM stacking. Audit interfaces will need to collect all
possible secids for possible reporting.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 drivers/android/binder.c              |  4 +---
 include/linux/security.h              |  7 +++---
 kernel/audit.c                        |  6 ++---
 kernel/auditfilter.c                  |  4 +---
 kernel/auditsc.c                      | 22 ++++++++++++------
 net/netlabel/netlabel_unlabeled.c     |  5 +++-
 net/netlabel/netlabel_user.h          |  6 ++++-
 security/integrity/ima/ima_appraise.c |  4 +++-
 security/integrity/ima/ima_main.c     | 33 +++++++++++++++------------
 security/security.c                   | 12 +++++++---
 10 files changed, 63 insertions(+), 40 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 1962f6b8abd0..144ac4f1c24f 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -3119,11 +3119,9 @@ static void binder_transaction(struct binder_proc *proc,
 	t->priority = task_nice(current);
 
 	if (target_node && target_node->txn_security_ctx) {
-		u32 secid;
 		struct lsmblob blob;
 
-		security_task_getsecid(proc->tsk, &secid);
-		lsmblob_init(&blob, secid);
+		security_task_getsecid(proc->tsk, &blob);
 		ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz);
 		if (ret) {
 			return_error = BR_FAILED_REPLY;
diff --git a/include/linux/security.h b/include/linux/security.h
index 41dc3053094e..cfd7cf4b0be9 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -400,7 +400,7 @@ int security_task_fix_setuid(struct cred *new, const struct cred *old,
 int security_task_setpgid(struct task_struct *p, pid_t pgid);
 int security_task_getpgid(struct task_struct *p);
 int security_task_getsid(struct task_struct *p);
-void security_task_getsecid(struct task_struct *p, u32 *secid);
+void security_task_getsecid(struct task_struct *p, struct lsmblob *blob);
 int security_task_setnice(struct task_struct *p, int nice);
 int security_task_setioprio(struct task_struct *p, int ioprio);
 int security_task_getioprio(struct task_struct *p);
@@ -1029,9 +1029,10 @@ static inline int security_task_getsid(struct task_struct *p)
 	return 0;
 }
 
-static inline void security_task_getsecid(struct task_struct *p, u32 *secid)
+static inline void security_task_getsecid(struct task_struct *p,
+					  struct lsmblob *blob)
 {
-	*secid = 0;
+	lsmblob_init(blob, 0);
 }
 
 static inline int security_task_setnice(struct task_struct *p, int nice)
diff --git a/kernel/audit.c b/kernel/audit.c
index d0338411d75d..a0205f3c23c7 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -2075,14 +2075,12 @@ int audit_log_task_context(struct audit_buffer *ab)
 	char *ctx = NULL;
 	unsigned len;
 	int error;
-	u32 sid;
 	struct lsmblob blob;
 
-	security_task_getsecid(current, &sid);
-	if (!sid)
+	security_task_getsecid(current, &blob);
+	if (!lsmblob_is_set(&blob))
 		return 0;
 
-	lsmblob_init(&blob, sid);
 	error = security_secid_to_secctx(&blob, &ctx, &len);
 	if (error) {
 		if (error != -EINVAL)
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 8786b95b60bd..8f244c98bb57 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1323,7 +1323,6 @@ int audit_filter(int msgtype, unsigned int listtype)
 		for (i = 0; i < e->rule.field_count; i++) {
 			struct audit_field *f = &e->rule.fields[i];
 			pid_t pid;
-			u32 sid;
 			struct lsmblob blob;
 
 			switch (f->type) {
@@ -1354,8 +1353,7 @@ int audit_filter(int msgtype, unsigned int listtype)
 			case AUDIT_SUBJ_SEN:
 			case AUDIT_SUBJ_CLR:
 				if (f->lsm_rule) {
-					security_task_getsecid(current, &sid);
-					lsmblob_init(&blob, sid);
+					security_task_getsecid(current, &blob);
 					result = security_audit_rule_match(
 							&blob, f->type,
 							f->op, f->lsm_rule);
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 148733ec3c72..7112fe31684d 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -444,7 +444,6 @@ static int audit_filter_rules(struct task_struct *tsk,
 {
 	const struct cred *cred;
 	int i, need_sid = 1;
-	u32 sid;
 	struct lsmblob blob;
 	unsigned int sessionid;
 
@@ -628,10 +627,9 @@ static int audit_filter_rules(struct task_struct *tsk,
 			   logged upon error */
 			if (f->lsm_rule) {
 				if (need_sid) {
-					security_task_getsecid(tsk, &sid);
+					security_task_getsecid(tsk, &blob);
 					need_sid = 0;
 				}
-				lsmblob_init(&blob, sid);
 				result = security_audit_rule_match(&blob,
 								   f->type,
 								   f->op,
@@ -2365,12 +2363,15 @@ int __audit_sockaddr(int len, void *a)
 void __audit_ptrace(struct task_struct *t)
 {
 	struct audit_context *context = audit_context();
+	struct lsmblob blob;
 
 	context->target_pid = task_tgid_nr(t);
 	context->target_auid = audit_get_loginuid(t);
 	context->target_uid = task_uid(t);
 	context->target_sessionid = audit_get_sessionid(t);
-	security_task_getsecid(t, &context->target_sid);
+	security_task_getsecid(t, &blob);
+	/* scaffolding - until target_sid is converted */
+	context->target_sid = blob.secid[0];
 	memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
 }
 
@@ -2387,6 +2388,7 @@ int audit_signal_info(int sig, struct task_struct *t)
 	struct audit_aux_data_pids *axp;
 	struct audit_context *ctx = audit_context();
 	kuid_t uid = current_uid(), auid, t_uid = task_uid(t);
+	struct lsmblob blob;
 
 	if (auditd_test_task(t) &&
 	    (sig == SIGTERM || sig == SIGHUP ||
@@ -2397,7 +2399,9 @@ int audit_signal_info(int sig, struct task_struct *t)
 			audit_sig_uid = auid;
 		else
 			audit_sig_uid = uid;
-		security_task_getsecid(current, &audit_sig_sid);
+		security_task_getsecid(current, &blob);
+		/* scaffolding until audit_sig_sid is converted */
+		audit_sig_sid = blob.secid[0];
 	}
 
 	if (!audit_signals || audit_dummy_context())
@@ -2410,7 +2414,9 @@ int audit_signal_info(int sig, struct task_struct *t)
 		ctx->target_auid = audit_get_loginuid(t);
 		ctx->target_uid = t_uid;
 		ctx->target_sessionid = audit_get_sessionid(t);
-		security_task_getsecid(t, &ctx->target_sid);
+		security_task_getsecid(t, &blob);
+		/* scaffolding until target_sid is converted */
+		ctx->target_sid = blob.secid[0];
 		memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
 		return 0;
 	}
@@ -2431,7 +2437,9 @@ int audit_signal_info(int sig, struct task_struct *t)
 	axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
 	axp->target_uid[axp->pid_count] = t_uid;
 	axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
-	security_task_getsecid(t, &axp->target_sid[axp->pid_count]);
+	security_task_getsecid(t, &blob);
+	/* scaffolding until target_sid is converted */
+	axp->target_sid[axp->pid_count] = blob.secid[0];
 	memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
 	axp->pid_count++;
 
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 2d8dd5b84457..2294aa9471e6 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -1552,11 +1552,14 @@ int __init netlbl_unlabel_defconf(void)
 	int ret_val;
 	struct netlbl_dom_map *entry;
 	struct netlbl_audit audit_info;
+	struct lsmblob blob;
 
 	/* Only the kernel is allowed to call this function and the only time
 	 * it is called is at bootup before the audit subsystem is reporting
 	 * messages so don't worry to much about these values. */
-	security_task_getsecid(current, &audit_info.secid);
+	security_task_getsecid(current, &blob);
+	/* scaffolding until audit_info.secid is converted */
+	audit_info.secid = blob.secid[0];
 	audit_info.loginuid = GLOBAL_ROOT_UID;
 	audit_info.sessionid = 0;
 
diff --git a/net/netlabel/netlabel_user.h b/net/netlabel/netlabel_user.h
index 4a397cde1a48..ab88baaaa50d 100644
--- a/net/netlabel/netlabel_user.h
+++ b/net/netlabel/netlabel_user.h
@@ -48,7 +48,11 @@
 static inline void netlbl_netlink_auditinfo(struct sk_buff *skb,
 					    struct netlbl_audit *audit_info)
 {
-	security_task_getsecid(current, &audit_info->secid);
+	struct lsmblob blob;
+
+	security_task_getsecid(current, &blob);
+	/* scaffolding until secid is converted */
+	audit_info->secid = blob.secid[0];
 	audit_info->loginuid = audit_get_loginuid(current);
 	audit_info->sessionid = audit_get_sessionid(current);
 }
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 5fb7127bbe68..85c7692fc4a3 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -51,11 +51,13 @@ bool is_ima_appraise_enabled(void)
 int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func)
 {
 	u32 secid;
+	struct lsmblob blob;
 
 	if (!ima_appraise)
 		return 0;
 
-	security_task_getsecid(current, &secid);
+	security_task_getsecid(current, &blob);
+	lsmblob_secid(&blob, &secid);
 	return ima_match_policy(inode, current_cred(), secid, func, mask,
 				IMA_APPRAISE | IMA_HASH, NULL);
 }
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 357edd140c09..fefa848cf0c7 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -335,12 +335,13 @@ static int process_measurement(struct file *file, const struct cred *cred,
  */
 int ima_file_mmap(struct file *file, unsigned long prot)
 {
-	u32 secid;
+	struct lsmblob blob;
 
 	if (file && (prot & PROT_EXEC)) {
-		security_task_getsecid(current, &secid);
-		return process_measurement(file, current_cred(), secid, NULL,
-					   0, MAY_EXEC, MMAP_CHECK);
+		security_task_getsecid(current, &blob);
+		/* scaffolding - until process_measurement changes */
+		return process_measurement(file, current_cred(), blob.secid[0],
+					   NULL, 0, MAY_EXEC, MMAP_CHECK);
 	}
 
 	return 0;
@@ -363,10 +364,12 @@ int ima_bprm_check(struct linux_binprm *bprm)
 {
 	int ret;
 	u32 secid;
+	struct lsmblob blob;
 
-	security_task_getsecid(current, &secid);
-	ret = process_measurement(bprm->file, current_cred(), secid, NULL, 0,
-				  MAY_EXEC, BPRM_CHECK);
+	security_task_getsecid(current, &blob);
+	/* scaffolding until process_measurement changes */
+	ret = process_measurement(bprm->file, current_cred(), blob.secid[0],
+				  NULL, 0, MAY_EXEC, BPRM_CHECK);
 	if (ret)
 		return ret;
 
@@ -387,10 +390,11 @@ int ima_bprm_check(struct linux_binprm *bprm)
  */
 int ima_file_check(struct file *file, int mask)
 {
-	u32 secid;
+	struct lsmblob blob;
 
-	security_task_getsecid(current, &secid);
-	return process_measurement(file, current_cred(), secid, NULL, 0,
+	security_task_getsecid(current, &blob);
+	/* scaffolding until process_measurement changes */
+	return process_measurement(file, current_cred(), blob.secid[0], NULL, 0,
 				   mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
 					   MAY_APPEND), FILE_CHECK);
 }
@@ -499,7 +503,7 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
 		       enum kernel_read_file_id read_id)
 {
 	enum ima_hooks func;
-	u32 secid;
+	struct lsmblob blob;
 
 	if (!file && read_id == READING_FIRMWARE) {
 		if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
@@ -521,9 +525,10 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
 	}
 
 	func = read_idmap[read_id] ?: FILE_CHECK;
-	security_task_getsecid(current, &secid);
-	return process_measurement(file, current_cred(), secid, buf, size,
-				   MAY_READ, func);
+	security_task_getsecid(current, &blob);
+	/* scaffolding until process_measurement changes */
+	return process_measurement(file, current_cred(), blob.secid[0], buf,
+				   size, MAY_READ, func);
 }
 
 /**
diff --git a/security/security.c b/security/security.c
index b4789c31e532..43076ae0373f 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1712,10 +1712,16 @@ int security_task_getsid(struct task_struct *p)
 	return call_int_hook(task_getsid, 0, p);
 }
 
-void security_task_getsecid(struct task_struct *p, u32 *secid)
+void security_task_getsecid(struct task_struct *p, struct lsmblob *blob)
 {
-	*secid = 0;
-	call_void_hook(task_getsecid, p, secid);
+	struct security_hook_list *hp;
+
+	lsmblob_init(blob, 0);
+	hlist_for_each_entry(hp, &security_hook_heads.task_getsecid, list) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		hp->hook.task_getsecid(p, &blob->secid[hp->lsmid->slot]);
+	}
 }
 EXPORT_SYMBOL(security_task_getsecid);
 
-- 
2.20.1


^ permalink raw reply related

* [PATCH v7 08/28] LSM: Use lsmblob in security_secctx_to_secid
From: Casey Schaufler @ 2019-08-07 19:43 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds
In-Reply-To: <20190807194410.9762-1-casey@schaufler-ca.com>

Change security_secctx_to_secid() to fill in a lsmblob instead
of a u32 secid. Multiple LSMs may be able to interpret the
string, and this allows for setting whichever secid is
appropriate. In some cases there is scaffolding where other
interfaces have yet to be converted.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/security.h          |  5 +++--
 kernel/cred.c                     |  4 +---
 net/netfilter/nft_meta.c          | 13 ++++++-------
 net/netfilter/xt_SECMARK.c        |  5 ++++-
 net/netlabel/netlabel_unlabeled.c | 14 ++++++++------
 security/security.c               | 18 +++++++++++++++---
 6 files changed, 37 insertions(+), 22 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index dcf20da87d1b..30337f1a9056 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -447,7 +447,8 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
 int security_netlink_send(struct sock *sk, struct sk_buff *skb);
 int security_ismaclabel(const char *name);
 int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen);
-int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid);
+int security_secctx_to_secid(const char *secdata, u32 seclen,
+			     struct lsmblob *blob);
 void security_release_secctx(char *secdata, u32 seclen);
 
 void security_inode_invalidate_secctx(struct inode *inode);
@@ -1230,7 +1231,7 @@ static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *secle
 
 static inline int security_secctx_to_secid(const char *secdata,
 					   u32 seclen,
-					   u32 *secid)
+					   struct lsmblob *blob)
 {
 	return -EOPNOTSUPP;
 }
diff --git a/kernel/cred.c b/kernel/cred.c
index 71c14dda107e..d70a2c02ced4 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -725,14 +725,12 @@ EXPORT_SYMBOL(set_security_override);
 int set_security_override_from_ctx(struct cred *new, const char *secctx)
 {
 	struct lsmblob blob;
-	u32 secid;
 	int ret;
 
-	ret = security_secctx_to_secid(secctx, strlen(secctx), &secid);
+	ret = security_secctx_to_secid(secctx, strlen(secctx), &blob);
 	if (ret < 0)
 		return ret;
 
-	lsmblob_init(&blob, secid);
 	return set_security_override(new, &blob);
 }
 EXPORT_SYMBOL(set_security_override_from_ctx);
diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c
index 987d2d6ce624..054fb4b48d51 100644
--- a/net/netfilter/nft_meta.c
+++ b/net/netfilter/nft_meta.c
@@ -576,21 +576,20 @@ static const struct nla_policy nft_secmark_policy[NFTA_SECMARK_MAX + 1] = {
 
 static int nft_secmark_compute_secid(struct nft_secmark *priv)
 {
-	u32 tmp_secid = 0;
+	struct lsmblob blob;
 	int err;
 
-	err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &tmp_secid);
+	err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &blob);
 	if (err)
 		return err;
 
-	if (!tmp_secid)
-		return -ENOENT;
-
-	err = security_secmark_relabel_packet(tmp_secid);
+	/* Using le[0] is scaffolding */
+	err = security_secmark_relabel_packet(blob.secid[0]);
 	if (err)
 		return err;
 
-	priv->secid = tmp_secid;
+	/* Using le[0] is scaffolding */
+	priv->secid = blob.secid[0];
 	return 0;
 }
 
diff --git a/net/netfilter/xt_SECMARK.c b/net/netfilter/xt_SECMARK.c
index f16202d26c20..8081fadc30e9 100644
--- a/net/netfilter/xt_SECMARK.c
+++ b/net/netfilter/xt_SECMARK.c
@@ -49,13 +49,14 @@ secmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
 
 static int checkentry_lsm(struct xt_secmark_target_info *info)
 {
+	struct lsmblob blob;
 	int err;
 
 	info->secctx[SECMARK_SECCTX_MAX - 1] = '\0';
 	info->secid = 0;
 
 	err = security_secctx_to_secid(info->secctx, strlen(info->secctx),
-				       &info->secid);
+				       &blob);
 	if (err) {
 		if (err == -EINVAL)
 			pr_info_ratelimited("invalid security context \'%s\'\n",
@@ -63,6 +64,8 @@ static int checkentry_lsm(struct xt_secmark_target_info *info)
 		return err;
 	}
 
+	/* scaffolding during the transition */
+	info->secid = blob.secid[0];
 	if (!info->secid) {
 		pr_info_ratelimited("unable to map security context \'%s\'\n",
 				    info->secctx);
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index c92894c3e40a..2976370e41aa 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -895,7 +895,7 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
 	void *addr;
 	void *mask;
 	u32 addr_len;
-	u32 secid;
+	struct lsmblob blob;
 	struct netlbl_audit audit_info;
 
 	/* Don't allow users to add both IPv4 and IPv6 addresses for a
@@ -919,12 +919,13 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
 	ret_val = security_secctx_to_secid(
 		                  nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
 				  nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
-				  &secid);
+				  &blob);
 	if (ret_val != 0)
 		return ret_val;
 
+	/* scaffolding with the [0] */
 	return netlbl_unlhsh_add(&init_net,
-				 dev_name, addr, mask, addr_len, secid,
+				 dev_name, addr, mask, addr_len, blob.secid[0],
 				 &audit_info);
 }
 
@@ -946,7 +947,7 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
 	void *addr;
 	void *mask;
 	u32 addr_len;
-	u32 secid;
+	struct lsmblob blob;
 	struct netlbl_audit audit_info;
 
 	/* Don't allow users to add both IPv4 and IPv6 addresses for a
@@ -968,12 +969,13 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
 	ret_val = security_secctx_to_secid(
 		                  nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
 				  nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
-				  &secid);
+				  &blob);
 	if (ret_val != 0)
 		return ret_val;
 
+	/* scaffolding with the [0] */
 	return netlbl_unlhsh_add(&init_net,
-				 NULL, addr, mask, addr_len, secid,
+				 NULL, addr, mask, addr_len, blob.secid[0],
 				 &audit_info);
 }
 
diff --git a/security/security.c b/security/security.c
index fe76dfa0f2fd..e231fbfd68f2 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1982,10 +1982,22 @@ int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
 }
 EXPORT_SYMBOL(security_secid_to_secctx);
 
-int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
+int security_secctx_to_secid(const char *secdata, u32 seclen,
+			     struct lsmblob *blob)
 {
-	*secid = 0;
-	return call_int_hook(secctx_to_secid, 0, secdata, seclen, secid);
+	struct security_hook_list *hp;
+	int rc;
+
+	lsmblob_init(blob, 0);
+	hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		rc = hp->hook.secctx_to_secid(secdata, seclen,
+					      &blob->secid[hp->lsmid->slot]);
+		if (rc != 0)
+			return rc;
+	}
+	return 0;
 }
 EXPORT_SYMBOL(security_secctx_to_secid);
 
-- 
2.20.1


^ permalink raw reply related

* [PATCH v7 09/28] LSM: Use lsmblob in security_secid_to_secctx
From: Casey Schaufler @ 2019-08-07 19:43 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds
In-Reply-To: <20190807194410.9762-1-casey@schaufler-ca.com>

Change security_secid_to_secctx() to take a lsmblob as input
instead of a u32 secid. It will then call the LSM hooks
using the lsmblob element allocated for that module. The
callers have been updated as well. This allows for the
possibility that more than one module may be called upon
to translate a secid to a string, as can occur in the
audit code.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 drivers/android/binder.c                |  4 +++-
 include/linux/security.h                |  5 +++--
 include/net/scm.h                       |  5 ++---
 kernel/audit.c                          |  9 +++++++--
 kernel/auditsc.c                        | 14 ++++++++++----
 net/ipv4/ip_sockglue.c                  |  3 +--
 net/netfilter/nf_conntrack_netlink.c    |  8 ++++++--
 net/netfilter/nf_conntrack_standalone.c |  4 +++-
 net/netfilter/nfnetlink_queue.c         |  8 ++++++--
 net/netlabel/netlabel_unlabeled.c       | 18 ++++++++++++++----
 net/netlabel/netlabel_user.c            |  6 +++---
 security/security.c                     | 16 +++++++++++++---
 12 files changed, 71 insertions(+), 29 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 8685882da64c..1962f6b8abd0 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -3120,9 +3120,11 @@ static void binder_transaction(struct binder_proc *proc,
 
 	if (target_node && target_node->txn_security_ctx) {
 		u32 secid;
+		struct lsmblob blob;
 
 		security_task_getsecid(proc->tsk, &secid);
-		ret = security_secid_to_secctx(secid, &secctx, &secctx_sz);
+		lsmblob_init(&blob, secid);
+		ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz);
 		if (ret) {
 			return_error = BR_FAILED_REPLY;
 			return_error_param = ret;
diff --git a/include/linux/security.h b/include/linux/security.h
index 30337f1a9056..7b4667cc4930 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -446,7 +446,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
 			 size_t size);
 int security_netlink_send(struct sock *sk, struct sk_buff *skb);
 int security_ismaclabel(const char *name);
-int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen);
+int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen);
 int security_secctx_to_secid(const char *secdata, u32 seclen,
 			     struct lsmblob *blob);
 void security_release_secctx(char *secdata, u32 seclen);
@@ -1224,7 +1224,8 @@ static inline int security_ismaclabel(const char *name)
 	return 0;
 }
 
-static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
+static inline int security_secid_to_secctx(struct lsmblob *blob,
+					   char **secdata, u32 *seclen)
 {
 	return -EOPNOTSUPP;
 }
diff --git a/include/net/scm.h b/include/net/scm.h
index e2e71c4bf9d0..31ae605fcc0a 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -97,9 +97,8 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
 	int err;
 
 	if (test_bit(SOCK_PASSSEC, &sock->flags)) {
-		/* Scaffolding - it has to be element 0 for now */
-		err = security_secid_to_secctx(scm->lsmblob.secid[0],
-					       &secdata, &seclen);
+		err = security_secid_to_secctx(&scm->lsmblob, &secdata,
+					       &seclen);
 
 		if (!err) {
 			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
diff --git a/kernel/audit.c b/kernel/audit.c
index c89ea48c70a6..d0338411d75d 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1430,7 +1430,10 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 	case AUDIT_SIGNAL_INFO:
 		len = 0;
 		if (audit_sig_sid) {
-			err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
+			struct lsmblob blob;
+
+			lsmblob_init(&blob, audit_sig_sid);
+			err = security_secid_to_secctx(&blob, &ctx, &len);
 			if (err)
 				return err;
 		}
@@ -2073,12 +2076,14 @@ int audit_log_task_context(struct audit_buffer *ab)
 	unsigned len;
 	int error;
 	u32 sid;
+	struct lsmblob blob;
 
 	security_task_getsecid(current, &sid);
 	if (!sid)
 		return 0;
 
-	error = security_secid_to_secctx(sid, &ctx, &len);
+	lsmblob_init(&blob, sid);
+	error = security_secid_to_secctx(&blob, &ctx, &len);
 	if (error) {
 		if (error != -EINVAL)
 			goto error_path;
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 18ee5556c086..d31914088a82 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -947,6 +947,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
 	char *ctx = NULL;
 	u32 len;
 	int rc = 0;
+	struct lsmblob blob;
 
 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
 	if (!ab)
@@ -956,7 +957,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
 			 from_kuid(&init_user_ns, auid),
 			 from_kuid(&init_user_ns, uid), sessionid);
 	if (sid) {
-		if (security_secid_to_secctx(sid, &ctx, &len)) {
+		lsmblob_init(&blob, sid);
+		if (security_secid_to_secctx(&blob, &ctx, &len)) {
 			audit_log_format(ab, " obj=(none)");
 			rc = 1;
 		} else {
@@ -1198,7 +1200,10 @@ static void show_special(struct audit_context *context, int *call_panic)
 		if (osid) {
 			char *ctx = NULL;
 			u32 len;
-			if (security_secid_to_secctx(osid, &ctx, &len)) {
+			struct lsmblob blob;
+
+			lsmblob_init(&blob, osid);
+			if (security_secid_to_secctx(&blob, &ctx, &len)) {
 				audit_log_format(ab, " osid=%u", osid);
 				*call_panic = 1;
 			} else {
@@ -1349,9 +1354,10 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
 	if (n->osid != 0) {
 		char *ctx = NULL;
 		u32 len;
+		struct lsmblob blob;
 
-		if (security_secid_to_secctx(
-			n->osid, &ctx, &len)) {
+		lsmblob_init(&blob, n->osid);
+		if (security_secid_to_secctx(&blob, &ctx, &len)) {
 			audit_log_format(ab, " osid=%u", n->osid);
 			if (call_panic)
 				*call_panic = 2;
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 2a5c868ce135..e05f4ef68bd8 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -139,8 +139,7 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
 	if (err)
 		return;
 
-	/* Scaffolding - it has to be element 0 */
-	err = security_secid_to_secctx(lb.secid[0], &secdata, &seclen);
+	err = security_secid_to_secctx(&lb, &secdata, &seclen);
 	if (err)
 		return;
 
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 66c596d287a5..ca0968f13240 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -330,8 +330,10 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
 	struct nlattr *nest_secctx;
 	int len, ret;
 	char *secctx;
+	struct lsmblob blob;
 
-	ret = security_secid_to_secctx(ct->secmark, &secctx, &len);
+	lsmblob_init(&blob, ct->secmark);
+	ret = security_secid_to_secctx(&blob, &secctx, &len);
 	if (ret)
 		return 0;
 
@@ -615,8 +617,10 @@ static inline int ctnetlink_secctx_size(const struct nf_conn *ct)
 {
 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 	int len, ret;
+	struct lsmblob blob;
 
-	ret = security_secid_to_secctx(ct->secmark, NULL, &len);
+	lsmblob_init(&blob, ct->secmark);
+	ret = security_secid_to_secctx(&blob, NULL, &len);
 	if (ret)
 		return 0;
 
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index c2ae14c720b4..c793103f3cd7 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -175,8 +175,10 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
 	int ret;
 	u32 len;
 	char *secctx;
+	struct lsmblob blob;
 
-	ret = security_secid_to_secctx(ct->secmark, &secctx, &len);
+	lsmblob_init(&blob, ct->secmark);
+	ret = security_secid_to_secctx(&blob, &secctx, &len);
 	if (ret)
 		return;
 
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index 0dcc3592d053..59211bff90ab 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -309,13 +309,17 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
 {
 	u32 seclen = 0;
 #if IS_ENABLED(CONFIG_NETWORK_SECMARK)
+	struct lsmblob blob;
+
 	if (!skb || !sk_fullsock(skb->sk))
 		return 0;
 
 	read_lock_bh(&skb->sk->sk_callback_lock);
 
-	if (skb->secmark)
-		security_secid_to_secctx(skb->secmark, secdata, &seclen);
+	if (skb->secmark) {
+		lsmblob_init(&blob, skb->secmark);
+		security_secid_to_secctx(&blob, secdata, &seclen);
+	}
 
 	read_unlock_bh(&skb->sk->sk_callback_lock);
 #endif
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 2976370e41aa..2d8dd5b84457 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -389,6 +389,7 @@ int netlbl_unlhsh_add(struct net *net,
 	struct audit_buffer *audit_buf = NULL;
 	char *secctx = NULL;
 	u32 secctx_len;
+	struct lsmblob blob;
 
 	if (addr_len != sizeof(struct in_addr) &&
 	    addr_len != sizeof(struct in6_addr))
@@ -451,7 +452,8 @@ int netlbl_unlhsh_add(struct net *net,
 unlhsh_add_return:
 	rcu_read_unlock();
 	if (audit_buf != NULL) {
-		if (security_secid_to_secctx(secid,
+		lsmblob_init(&blob, secid);
+		if (security_secid_to_secctx(&blob,
 					     &secctx,
 					     &secctx_len) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s", secctx);
@@ -488,6 +490,7 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
 	struct net_device *dev;
 	char *secctx;
 	u32 secctx_len;
+	struct lsmblob blob;
 
 	spin_lock(&netlbl_unlhsh_lock);
 	list_entry = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
@@ -507,8 +510,10 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
 					  addr->s_addr, mask->s_addr);
 		if (dev != NULL)
 			dev_put(dev);
+		if (entry != NULL)
+			lsmblob_init(&blob, entry->secid);
 		if (entry != NULL &&
-		    security_secid_to_secctx(entry->secid,
+		    security_secid_to_secctx(&blob,
 					     &secctx, &secctx_len) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s", secctx);
 			security_release_secctx(secctx, secctx_len);
@@ -550,6 +555,7 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
 	struct net_device *dev;
 	char *secctx;
 	u32 secctx_len;
+	struct lsmblob blob;
 
 	spin_lock(&netlbl_unlhsh_lock);
 	list_entry = netlbl_af6list_remove(addr, mask, &iface->addr6_list);
@@ -568,8 +574,10 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
 					  addr, mask);
 		if (dev != NULL)
 			dev_put(dev);
+		if (entry != NULL)
+			lsmblob_init(&blob, entry->secid);
 		if (entry != NULL &&
-		    security_secid_to_secctx(entry->secid,
+		    security_secid_to_secctx(&blob,
 					     &secctx, &secctx_len) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s", secctx);
 			security_release_secctx(secctx, secctx_len);
@@ -1090,6 +1098,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
 	u32 secid;
 	char *secctx;
 	u32 secctx_len;
+	struct lsmblob blob;
 
 	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
 			   cb_arg->seq, &netlbl_unlabel_gnl_family,
@@ -1144,7 +1153,8 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
 		secid = addr6->secid;
 	}
 
-	ret_val = security_secid_to_secctx(secid, &secctx, &secctx_len);
+	lsmblob_init(&blob, secid);
+	ret_val = security_secid_to_secctx(&blob, &secctx, &secctx_len);
 	if (ret_val != 0)
 		goto list_cb_failure;
 	ret_val = nla_put(cb_arg->skb,
diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
index 4676f5bb16ae..2ccc6567e2a2 100644
--- a/net/netlabel/netlabel_user.c
+++ b/net/netlabel/netlabel_user.c
@@ -100,6 +100,7 @@ struct audit_buffer *netlbl_audit_start_common(int type,
 	struct audit_buffer *audit_buf;
 	char *secctx;
 	u32 secctx_len;
+	struct lsmblob blob;
 
 	if (audit_enabled == AUDIT_OFF)
 		return NULL;
@@ -112,10 +113,9 @@ struct audit_buffer *netlbl_audit_start_common(int type,
 			 from_kuid(&init_user_ns, audit_info->loginuid),
 			 audit_info->sessionid);
 
+	lsmblob_init(&blob, audit_info->secid);
 	if (audit_info->secid != 0 &&
-	    security_secid_to_secctx(audit_info->secid,
-				     &secctx,
-				     &secctx_len) == 0) {
+	    security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) {
 		audit_log_format(audit_buf, " subj=%s", secctx);
 		security_release_secctx(secctx, secctx_len);
 	}
diff --git a/security/security.c b/security/security.c
index e231fbfd68f2..837c3c6b6e7c 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1975,10 +1975,20 @@ int security_ismaclabel(const char *name)
 }
 EXPORT_SYMBOL(security_ismaclabel);
 
-int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
+int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen)
 {
-	return call_int_hook(secid_to_secctx, -EOPNOTSUPP, secid, secdata,
-				seclen);
+	struct security_hook_list *hp;
+	int rc;
+
+	hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		rc = hp->hook.secid_to_secctx(blob->secid[hp->lsmid->slot],
+					      secdata, seclen);
+		if (rc != 0)
+			return rc;
+	}
+	return 0;
 }
 EXPORT_SYMBOL(security_secid_to_secctx);
 
-- 
2.20.1


^ permalink raw reply related

* [PATCH v7 05/28] LSM: Use lsmblob in security_audit_rule_match
From: Casey Schaufler @ 2019-08-07 19:43 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds
In-Reply-To: <20190807194410.9762-1-casey@schaufler-ca.com>

Change the secid parameter of security_audit_rule_match
to a lsmblob structure pointer. Pass the entry from the
lsmblob structure for the approprite slot to the LSM hook.

Change the users of security_audit_rule_match to use the
lsmblob instead of a u32. In some cases this requires a
temporary conversion using lsmblob_init() that will go
away when other interfaces get converted.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/security.h            |  7 ++++---
 kernel/auditfilter.c                |  7 +++++--
 kernel/auditsc.c                    | 14 ++++++++++----
 security/integrity/ima/ima.h        |  4 ++--
 security/integrity/ima/ima_policy.c |  7 +++++--
 security/security.c                 | 18 +++++++++++++++---
 6 files changed, 41 insertions(+), 16 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index 5bb8b9a6fa84..4f8b478bc3a1 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1761,7 +1761,8 @@ static inline int security_key_getsecurity(struct key *key, char **_buffer)
 #ifdef CONFIG_SECURITY
 int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule);
 int security_audit_rule_known(struct audit_krule *krule);
-int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule);
+int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op,
+			      void *lsmrule);
 void security_audit_rule_free(void *lsmrule);
 
 #else
@@ -1777,8 +1778,8 @@ static inline int security_audit_rule_known(struct audit_krule *krule)
 	return 0;
 }
 
-static inline int security_audit_rule_match(u32 secid, u32 field, u32 op,
-					    void *lsmrule)
+static inline int security_audit_rule_match(struct lsmblob *blob, u32 field,
+					    u32 op, void *lsmrule)
 {
 	return 0;
 }
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 63f8b3f26fab..8786b95b60bd 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1324,6 +1324,7 @@ int audit_filter(int msgtype, unsigned int listtype)
 			struct audit_field *f = &e->rule.fields[i];
 			pid_t pid;
 			u32 sid;
+			struct lsmblob blob;
 
 			switch (f->type) {
 			case AUDIT_PID:
@@ -1354,8 +1355,10 @@ int audit_filter(int msgtype, unsigned int listtype)
 			case AUDIT_SUBJ_CLR:
 				if (f->lsm_rule) {
 					security_task_getsecid(current, &sid);
-					result = security_audit_rule_match(sid,
-						   f->type, f->op, f->lsm_rule);
+					lsmblob_init(&blob, sid);
+					result = security_audit_rule_match(
+							&blob, f->type,
+							f->op, f->lsm_rule);
 				}
 				break;
 			case AUDIT_EXE:
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index d1eab1d4a930..18ee5556c086 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -445,6 +445,7 @@ static int audit_filter_rules(struct task_struct *tsk,
 	const struct cred *cred;
 	int i, need_sid = 1;
 	u32 sid;
+	struct lsmblob blob;
 	unsigned int sessionid;
 
 	cred = rcu_dereference_check(tsk->cred, tsk == current || task_creation);
@@ -630,7 +631,9 @@ static int audit_filter_rules(struct task_struct *tsk,
 					security_task_getsecid(tsk, &sid);
 					need_sid = 0;
 				}
-				result = security_audit_rule_match(sid, f->type,
+				lsmblob_init(&blob, sid);
+				result = security_audit_rule_match(&blob,
+								   f->type,
 								   f->op,
 								   f->lsm_rule);
 			}
@@ -645,15 +648,17 @@ static int audit_filter_rules(struct task_struct *tsk,
 			if (f->lsm_rule) {
 				/* Find files that match */
 				if (name) {
+					lsmblob_init(&blob, name->osid);
 					result = security_audit_rule_match(
-								name->osid,
+								&blob,
 								f->type,
 								f->op,
 								f->lsm_rule);
 				} else if (ctx) {
 					list_for_each_entry(n, &ctx->names_list, list) {
+						lsmblob_init(&blob, n->osid);
 						if (security_audit_rule_match(
-								n->osid,
+								&blob,
 								f->type,
 								f->op,
 								f->lsm_rule)) {
@@ -665,7 +670,8 @@ static int audit_filter_rules(struct task_struct *tsk,
 				/* Find ipc objects that match */
 				if (!ctx || ctx->type != AUDIT_IPC)
 					break;
-				if (security_audit_rule_match(ctx->ipc.osid,
+				lsmblob_init(&blob, ctx->ipc.osid);
+				if (security_audit_rule_match(&blob,
 							      f->type, f->op,
 							      f->lsm_rule))
 					++result;
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index d213e835c498..5a337239d9e4 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -307,8 +307,8 @@ static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
 	return -EINVAL;
 }
 
-static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
-					     void *lsmrule)
+static inline int security_filter_rule_match(struct lsmblob *blob, u32 field,
+					     u32 op, void *lsmrule)
 {
 	return -EINVAL;
 }
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index e0cc323f948f..e7b8ce942950 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -327,6 +327,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 	for (i = 0; i < MAX_LSM_RULES; i++) {
 		int rc = 0;
 		u32 osid;
+		struct lsmblob blob;
 		int retried = 0;
 
 		if (!rule->lsm[i].rule)
@@ -337,7 +338,8 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 		case LSM_OBJ_ROLE:
 		case LSM_OBJ_TYPE:
 			security_inode_getsecid(inode, &osid);
-			rc = security_filter_rule_match(osid,
+			lsmblob_init(&blob, osid);
+			rc = security_filter_rule_match(&blob,
 							rule->lsm[i].type,
 							Audit_equal,
 							rule->lsm[i].rule);
@@ -345,7 +347,8 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 		case LSM_SUBJ_USER:
 		case LSM_SUBJ_ROLE:
 		case LSM_SUBJ_TYPE:
-			rc = security_filter_rule_match(secid,
+			lsmblob_init(&blob, secid);
+			rc = security_filter_rule_match(&blob,
 							rule->lsm[i].type,
 							Audit_equal,
 							rule->lsm[i].rule);
diff --git a/security/security.c b/security/security.c
index 27e2db3d6b04..fa6e425e6f29 100644
--- a/security/security.c
+++ b/security/security.c
@@ -424,7 +424,7 @@ static int lsm_append(const char *new, char **result)
 /*
  * Current index to use while initializing the lsmblob secid list.
  */
-static int lsm_slot __initdata;
+static int lsm_slot __lsm_ro_after_init;
 
 /**
  * security_add_hooks - Add a modules hooks to the hook lists.
@@ -2433,9 +2433,21 @@ void security_audit_rule_free(void *lsmrule)
 	call_void_hook(audit_rule_free, lsmrule);
 }
 
-int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule)
+int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op,
+			      void *lsmrule)
 {
-	return call_int_hook(audit_rule_match, 0, secid, field, op, lsmrule);
+	struct security_hook_list *hp;
+	int rc;
+
+	hlist_for_each_entry(hp, &security_hook_heads.audit_rule_match, list) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		rc = hp->hook.audit_rule_match(blob->secid[hp->lsmid->slot],
+					       field, op, lsmrule);
+		if (rc != 0)
+			return rc;
+	}
+	return 0;
 }
 #endif /* CONFIG_AUDIT */
 
-- 
2.20.1


^ permalink raw reply related

* [PATCH v7 06/28] LSM: Use lsmblob in security_kernel_act_as
From: Casey Schaufler @ 2019-08-07 19:43 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds
In-Reply-To: <20190807194410.9762-1-casey@schaufler-ca.com>

Change the security_kernel_act_as interface to use a lsmblob
structure in place of the single u32 secid in support of
module stacking. Change it's only caller, set_security_override,
to do the same. Change that one's only caller,
set_security_override_from_ctx, to call it with the new
parameter type.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/cred.h     |  3 ++-
 include/linux/security.h |  5 +++--
 kernel/cred.c            | 10 ++++++----
 security/security.c      | 14 ++++++++++++--
 4 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/include/linux/cred.h b/include/linux/cred.h
index efb6edf32de7..9a21c376ed97 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -22,6 +22,7 @@
 
 struct cred;
 struct inode;
+struct lsmblob;
 
 /*
  * COW Supplementary groups list
@@ -165,7 +166,7 @@ extern const struct cred *override_creds(const struct cred *);
 extern void revert_creds(const struct cred *);
 extern struct cred *prepare_kernel_cred(struct task_struct *);
 extern int change_create_files_as(struct cred *, struct inode *);
-extern int set_security_override(struct cred *, u32);
+extern int set_security_override(struct cred *, struct lsmblob *);
 extern int set_security_override_from_ctx(struct cred *, const char *);
 extern int set_create_files_as(struct cred *, struct inode *);
 extern int cred_fscmp(const struct cred *, const struct cred *);
diff --git a/include/linux/security.h b/include/linux/security.h
index 4f8b478bc3a1..313e45a3cac3 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -388,7 +388,7 @@ void security_cred_free(struct cred *cred);
 int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp);
 void security_transfer_creds(struct cred *new, const struct cred *old);
 void security_cred_getsecid(const struct cred *c, u32 *secid);
-int security_kernel_act_as(struct cred *new, u32 secid);
+int security_kernel_act_as(struct cred *new, struct lsmblob *blob);
 int security_kernel_create_files_as(struct cred *new, struct inode *inode);
 int security_kernel_module_request(char *kmod_name);
 int security_kernel_load_data(enum kernel_load_data_id id);
@@ -971,7 +971,8 @@ static inline void security_transfer_creds(struct cred *new,
 {
 }
 
-static inline int security_kernel_act_as(struct cred *cred, u32 secid)
+static inline int security_kernel_act_as(struct cred *cred,
+					 struct lsmblob *blob)
 {
 	return 0;
 }
diff --git a/kernel/cred.c b/kernel/cred.c
index 45d77284aed0..71c14dda107e 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -701,14 +701,14 @@ EXPORT_SYMBOL(prepare_kernel_cred);
 /**
  * set_security_override - Set the security ID in a set of credentials
  * @new: The credentials to alter
- * @secid: The LSM security ID to set
+ * @blob: The LSM security information to set
  *
  * Set the LSM security ID in a set of credentials so that the subjective
  * security is overridden when an alternative set of credentials is used.
  */
-int set_security_override(struct cred *new, u32 secid)
+int set_security_override(struct cred *new, struct lsmblob *blob)
 {
-	return security_kernel_act_as(new, secid);
+	return security_kernel_act_as(new, blob);
 }
 EXPORT_SYMBOL(set_security_override);
 
@@ -724,6 +724,7 @@ EXPORT_SYMBOL(set_security_override);
  */
 int set_security_override_from_ctx(struct cred *new, const char *secctx)
 {
+	struct lsmblob blob;
 	u32 secid;
 	int ret;
 
@@ -731,7 +732,8 @@ int set_security_override_from_ctx(struct cred *new, const char *secctx)
 	if (ret < 0)
 		return ret;
 
-	return set_security_override(new, secid);
+	lsmblob_init(&blob, secid);
+	return set_security_override(new, &blob);
 }
 EXPORT_SYMBOL(set_security_override_from_ctx);
 
diff --git a/security/security.c b/security/security.c
index fa6e425e6f29..fa7ab1334f22 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1627,9 +1627,19 @@ void security_cred_getsecid(const struct cred *c, u32 *secid)
 }
 EXPORT_SYMBOL(security_cred_getsecid);
 
-int security_kernel_act_as(struct cred *new, u32 secid)
+int security_kernel_act_as(struct cred *new, struct lsmblob *blob)
 {
-	return call_int_hook(kernel_act_as, 0, new, secid);
+	struct security_hook_list *hp;
+	int rc;
+
+	hlist_for_each_entry(hp, &security_hook_heads.kernel_act_as, list) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		rc = hp->hook.kernel_act_as(new, blob->secid[hp->lsmid->slot]);
+		if (rc != 0)
+			return rc;
+	}
+	return 0;
 }
 
 int security_kernel_create_files_as(struct cred *new, struct inode *inode)
-- 
2.20.1


^ permalink raw reply related

* [PATCH v7 07/28] net: Prepare UDS for security module stacking
From: Casey Schaufler @ 2019-08-07 19:43 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds
In-Reply-To: <20190807194410.9762-1-casey@schaufler-ca.com>

Change the data used in UDS SO_PEERSEC processing from a
secid to a more general struct lsmblob. Update the
security_socket_getpeersec_dgram() interface to use the
lsmblob. There is a small amount of scaffolding code
that will come out when the security_secid_to_secctx()
code is brought in line with the lsmblob.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/security.h |  7 +++++--
 include/net/af_unix.h    |  2 +-
 include/net/scm.h        |  8 +++++---
 net/ipv4/ip_sockglue.c   |  8 +++++---
 net/unix/af_unix.c       |  6 +++---
 security/security.c      | 18 +++++++++++++++---
 6 files changed, 34 insertions(+), 15 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index 313e45a3cac3..dcf20da87d1b 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1280,7 +1280,8 @@ int security_socket_shutdown(struct socket *sock, int how);
 int security_sock_rcv_skb(struct sock *sk, struct sk_buff *skb);
 int security_socket_getpeersec_stream(struct socket *sock, char __user *optval,
 				      int __user *optlen, unsigned len);
-int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid);
+int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb,
+				     struct lsmblob *blob);
 int security_sk_alloc(struct sock *sk, int family, gfp_t priority);
 void security_sk_free(struct sock *sk);
 void security_sk_clone(const struct sock *sk, struct sock *newsk);
@@ -1418,7 +1419,9 @@ static inline int security_socket_getpeersec_stream(struct socket *sock, char __
 	return -ENOPROTOOPT;
 }
 
-static inline int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
+static inline int security_socket_getpeersec_dgram(struct socket *sock,
+						   struct sk_buff *skb,
+						   struct lsmblob *blob)
 {
 	return -ENOPROTOOPT;
 }
diff --git a/include/net/af_unix.h b/include/net/af_unix.h
index 3426d6dacc45..933492c08b8c 100644
--- a/include/net/af_unix.h
+++ b/include/net/af_unix.h
@@ -36,7 +36,7 @@ struct unix_skb_parms {
 	kgid_t			gid;
 	struct scm_fp_list	*fp;		/* Passed files		*/
 #ifdef CONFIG_SECURITY_NETWORK
-	u32			secid;		/* Security ID		*/
+	struct lsmblob		lsmblob;	/* Security LSM data	*/
 #endif
 	u32			consumed;
 } __randomize_layout;
diff --git a/include/net/scm.h b/include/net/scm.h
index 1ce365f4c256..e2e71c4bf9d0 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -33,7 +33,7 @@ struct scm_cookie {
 	struct scm_fp_list	*fp;		/* Passed files		*/
 	struct scm_creds	creds;		/* Skb credentials	*/
 #ifdef CONFIG_SECURITY_NETWORK
-	u32			secid;		/* Passed security ID 	*/
+	struct lsmblob		lsmblob;	/* Passed LSM data	*/
 #endif
 };
 
@@ -46,7 +46,7 @@ struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl);
 #ifdef CONFIG_SECURITY_NETWORK
 static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
 {
-	security_socket_getpeersec_dgram(sock, NULL, &scm->secid);
+	security_socket_getpeersec_dgram(sock, NULL, &scm->lsmblob);
 }
 #else
 static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
@@ -97,7 +97,9 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
 	int err;
 
 	if (test_bit(SOCK_PASSSEC, &sock->flags)) {
-		err = security_secid_to_secctx(scm->secid, &secdata, &seclen);
+		/* Scaffolding - it has to be element 0 for now */
+		err = security_secid_to_secctx(scm->lsmblob.secid[0],
+					       &secdata, &seclen);
 
 		if (!err) {
 			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 82f341e84fae..2a5c868ce135 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -130,15 +130,17 @@ static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb,
 
 static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
 {
+	struct lsmblob lb;
 	char *secdata;
-	u32 seclen, secid;
+	u32 seclen;
 	int err;
 
-	err = security_socket_getpeersec_dgram(NULL, skb, &secid);
+	err = security_socket_getpeersec_dgram(NULL, skb, &lb);
 	if (err)
 		return;
 
-	err = security_secid_to_secctx(secid, &secdata, &seclen);
+	/* Scaffolding - it has to be element 0 */
+	err = security_secid_to_secctx(lb.secid[0], &secdata, &seclen);
 	if (err)
 		return;
 
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index ddb838a1b74c..c50a004a1389 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -143,17 +143,17 @@ static struct hlist_head *unix_sockets_unbound(void *addr)
 #ifdef CONFIG_SECURITY_NETWORK
 static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
 {
-	UNIXCB(skb).secid = scm->secid;
+	UNIXCB(skb).lsmblob = scm->lsmblob;
 }
 
 static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
 {
-	scm->secid = UNIXCB(skb).secid;
+	scm->lsmblob = UNIXCB(skb).lsmblob;
 }
 
 static inline bool unix_secdata_eq(struct scm_cookie *scm, struct sk_buff *skb)
 {
-	return (scm->secid == UNIXCB(skb).secid);
+	return lsmblob_equal(&scm->lsmblob, &(UNIXCB(skb).lsmblob));
 }
 #else
 static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
diff --git a/security/security.c b/security/security.c
index fa7ab1334f22..fe76dfa0f2fd 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2120,10 +2120,22 @@ int security_socket_getpeersec_stream(struct socket *sock, char __user *optval,
 				optval, optlen, len);
 }
 
-int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
+int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb,
+				     struct lsmblob *blob)
 {
-	return call_int_hook(socket_getpeersec_dgram, -ENOPROTOOPT, sock,
-			     skb, secid);
+	struct security_hook_list *hp;
+	int rc = -ENOPROTOOPT;
+
+	hlist_for_each_entry(hp, &security_hook_heads.socket_getpeersec_dgram,
+			     list) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		rc = hp->hook.socket_getpeersec_dgram(sock, skb,
+						&blob->secid[hp->lsmid->slot]);
+		if (rc != 0)
+			break;
+	}
+	return rc;
 }
 EXPORT_SYMBOL(security_socket_getpeersec_dgram);
 
-- 
2.20.1


^ permalink raw reply related

* [PATCH v7 04/28] LSM: Create and manage the lsmblob data structure.
From: Casey Schaufler @ 2019-08-07 19:43 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds
In-Reply-To: <20190807194410.9762-1-casey@schaufler-ca.com>

When more than one security module is exporting data to
audit and networking sub-systems a single 32 bit integer
is no longer sufficient to represent the data. Add a
structure to be used instead.

The lsmblob structure is currently an array of
u32 "secids". There is an entry for each of the
security modules built into the system that would
use secids if active. The system assigns the module
a "slot" when it registers hooks. If modules are
compiled in but not registered there will be unused
slots.

A new lsm_id structure, which contains the name
of the LSM and its slot number, is created. There
is an instance for each LSM, which assigns the name
and passes it to the infrastructure to set the slot.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/lsm_hooks.h  | 12 +++++--
 include/linux/security.h   | 66 ++++++++++++++++++++++++++++++++++++++
 security/apparmor/lsm.c    |  7 +++-
 security/commoncap.c       |  7 +++-
 security/loadpin/loadpin.c |  8 ++++-
 security/safesetid/lsm.c   |  8 ++++-
 security/security.c        | 31 ++++++++++++++----
 security/selinux/hooks.c   |  8 ++++-
 security/smack/smack_lsm.c |  7 +++-
 security/tomoyo/tomoyo.c   |  8 ++++-
 security/yama/yama_lsm.c   |  7 +++-
 11 files changed, 152 insertions(+), 17 deletions(-)

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 3fe39abccc8f..fe1fb7a69ee5 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -2029,6 +2029,14 @@ struct security_hook_heads {
 #endif /* CONFIG_BPF_SYSCALL */
 } __randomize_layout;
 
+/*
+ * Information that identifies a security module.
+ */
+struct lsm_id {
+	const char	*lsm;	/* Name of the LSM */
+	int		slot;	/* Slot in lsmblob if one is allocated */
+};
+
 /*
  * Security module hook list structure.
  * For use with generic list macros for common operations.
@@ -2037,7 +2045,7 @@ struct security_hook_list {
 	struct hlist_node		list;
 	struct hlist_head		*head;
 	union security_list_options	hook;
-	char				*lsm;
+	struct lsm_id			*lsmid;
 } __randomize_layout;
 
 /*
@@ -2068,7 +2076,7 @@ extern struct security_hook_heads security_hook_heads;
 extern char *lsm_names;
 
 extern void security_add_hooks(struct security_hook_list *hooks, int count,
-				char *lsm);
+			       struct lsm_id *lsmid);
 
 #define LSM_FLAG_LEGACY_MAJOR	BIT(0)
 #define LSM_FLAG_EXCLUSIVE	BIT(1)
diff --git a/include/linux/security.h b/include/linux/security.h
index 49f2685324b0..5bb8b9a6fa84 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -76,6 +76,72 @@ enum lsm_event {
 	LSM_POLICY_CHANGE,
 };
 
+/*
+ * Data exported by the security modules
+ *
+ * Any LSM that provides secid or secctx based hooks must be included.
+ */
+#define LSMBLOB_ENTRIES ( \
+	(IS_ENABLED(CONFIG_SECURITY_SELINUX) ? 1 : 0) + \
+	(IS_ENABLED(CONFIG_SECURITY_SMACK) ? 1 : 0) + \
+	(IS_ENABLED(CONFIG_SECURITY_APPARMOR) ? 1 : 0))
+
+struct lsmblob {
+	u32     secid[LSMBLOB_ENTRIES];
+};
+
+#define LSMBLOB_INVALID		-1	/* Not a valid LSM slot number */
+#define LSMBLOB_NEEDED		-2	/* Slot requested on initialization */
+#define LSMBLOB_NOT_NEEDED	-3	/* Slot not requested */
+
+/**
+ * lsmblob_init - initialize an lsmblob structure.
+ * @blob: Pointer to the data to initialize
+ * @secid: The initial secid value
+ *
+ * Set all secid for all modules to the specified value.
+ */
+static inline void lsmblob_init(struct lsmblob *blob, u32 secid)
+{
+	int i;
+
+	for (i = 0; i < LSMBLOB_ENTRIES; i++)
+		blob->secid[i] = secid;
+}
+
+/**
+ * lsmblob_is_set - report if there is an value in the lsmblob
+ * @blob: Pointer to the exported LSM data
+ *
+ * Returns true if there is a secid set, false otherwise
+ */
+static inline bool lsmblob_is_set(struct lsmblob *blob)
+{
+	int i;
+
+	for (i = 0; i < LSMBLOB_ENTRIES; i++)
+		if (blob->secid[i] != 0)
+			return true;
+	return false;
+}
+
+/**
+ * lsmblob_equal - report if the two lsmblob's are equal
+ * @bloba: Pointer to one LSM data
+ * @blobb: Pointer to the other LSM data
+ *
+ * Returns true if all entries in the two are equal, false otherwise
+ */
+static inline bool lsmblob_equal(struct lsmblob *bloba, struct lsmblob *blobb)
+{
+	int i;
+
+	for (i = 0; i < LSMBLOB_ENTRIES; i++)
+		if (bloba->secid[i] != blobb->secid[i])
+			return false;
+	return true;
+}
+
 /* These functions are in security/commoncap.c */
 extern int cap_capable(const struct cred *cred, struct user_namespace *ns,
 		       int cap, unsigned int opts);
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 2716e7731279..ec2e39aa9a84 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -1138,6 +1138,11 @@ struct lsm_blob_sizes apparmor_blob_sizes __lsm_ro_after_init = {
 	.lbs_sock = sizeof(struct aa_sk_ctx),
 };
 
+static struct lsm_id apparmor_lsmid __lsm_ro_after_init = {
+	.lsm  = "apparmor",
+	.slot = LSMBLOB_NEEDED
+};
+
 static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check),
 	LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme),
@@ -1679,7 +1684,7 @@ static int __init apparmor_init(void)
 		goto buffers_out;
 	}
 	security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks),
-				"apparmor");
+				&apparmor_lsmid);
 
 	/* Report that AppArmor successfully initialized */
 	apparmor_initialized = 1;
diff --git a/security/commoncap.c b/security/commoncap.c
index afd9679ca866..973e6c7009d0 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -1344,6 +1344,11 @@ int cap_mmap_file(struct file *file, unsigned long reqprot,
 
 #ifdef CONFIG_SECURITY
 
+static struct lsm_id capability_lsmid __lsm_ro_after_init = {
+	.lsm  = "capability",
+	.slot = LSMBLOB_NOT_NEEDED
+};
+
 static struct security_hook_list capability_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(capable, cap_capable),
 	LSM_HOOK_INIT(settime, cap_settime),
@@ -1368,7 +1373,7 @@ static struct security_hook_list capability_hooks[] __lsm_ro_after_init = {
 static int __init capability_init(void)
 {
 	security_add_hooks(capability_hooks, ARRAY_SIZE(capability_hooks),
-				"capability");
+			   &capability_lsmid);
 	return 0;
 }
 
diff --git a/security/loadpin/loadpin.c b/security/loadpin/loadpin.c
index 055fb0a64169..7b23fdf24e27 100644
--- a/security/loadpin/loadpin.c
+++ b/security/loadpin/loadpin.c
@@ -181,6 +181,11 @@ static int loadpin_load_data(enum kernel_load_data_id id)
 	return loadpin_read_file(NULL, (enum kernel_read_file_id) id);
 }
 
+static struct lsm_id loadpin_lsmid __lsm_ro_after_init = {
+	.lsm  = "loadpin",
+	.slot = LSMBLOB_NOT_NEEDED
+};
+
 static struct security_hook_list loadpin_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(sb_free_security, loadpin_sb_free_security),
 	LSM_HOOK_INIT(kernel_read_file, loadpin_read_file),
@@ -191,7 +196,8 @@ static int __init loadpin_init(void)
 {
 	pr_info("ready to pin (currently %senforcing)\n",
 		enforce ? "" : "not ");
-	security_add_hooks(loadpin_hooks, ARRAY_SIZE(loadpin_hooks), "loadpin");
+	security_add_hooks(loadpin_hooks, ARRAY_SIZE(loadpin_hooks),
+			   &loadpin_lsmid);
 	return 0;
 }
 
diff --git a/security/safesetid/lsm.c b/security/safesetid/lsm.c
index cecd38e2ac80..4a96cd8c0d15 100644
--- a/security/safesetid/lsm.c
+++ b/security/safesetid/lsm.c
@@ -255,6 +255,11 @@ void flush_safesetid_whitelist_entries(void)
 	}
 }
 
+static struct lsm_id safesetid_lsmid __lsm_ro_after_init = {
+	.lsm  = "safesetid",
+	.slot = LSMBLOB_NOT_NEEDED
+};
+
 static struct security_hook_list safesetid_security_hooks[] = {
 	LSM_HOOK_INIT(task_fix_setuid, safesetid_task_fix_setuid),
 	LSM_HOOK_INIT(capable, safesetid_security_capable)
@@ -263,7 +268,8 @@ static struct security_hook_list safesetid_security_hooks[] = {
 static int __init safesetid_security_init(void)
 {
 	security_add_hooks(safesetid_security_hooks,
-			   ARRAY_SIZE(safesetid_security_hooks), "safesetid");
+			   ARRAY_SIZE(safesetid_security_hooks),
+			   &safesetid_lsmid);
 
 	/* Report that SafeSetID successfully initialized */
 	safesetid_initialized = 1;
diff --git a/security/security.c b/security/security.c
index 7cfedb90210a..27e2db3d6b04 100644
--- a/security/security.c
+++ b/security/security.c
@@ -317,6 +317,7 @@ static void __init ordered_lsm_init(void)
 	init_debug("sock blob size       = %d\n", blob_sizes.lbs_sock);
 	init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock);
 	init_debug("task blob size       = %d\n", blob_sizes.lbs_task);
+	init_debug("lsmblob size         = %lu\n", sizeof(struct lsmblob));
 
 	/*
 	 * Create any kmem_caches needed for blobs
@@ -399,7 +400,7 @@ static bool match_last_lsm(const char *list, const char *lsm)
 	return !strcmp(last, lsm);
 }
 
-static int lsm_append(char *new, char **result)
+static int lsm_append(const char *new, char **result)
 {
 	char *cp;
 
@@ -420,24 +421,40 @@ static int lsm_append(char *new, char **result)
 	return 0;
 }
 
+/*
+ * Current index to use while initializing the lsmblob secid list.
+ */
+static int lsm_slot __initdata;
+
 /**
  * security_add_hooks - Add a modules hooks to the hook lists.
  * @hooks: the hooks to add
  * @count: the number of hooks to add
- * @lsm: the name of the security module
+ * @lsmid: the identification information for the security module
  *
  * Each LSM has to register its hooks with the infrastructure.
+ * If the LSM is using hooks that export secids allocate a slot
+ * for it in the lsmblob.
  */
 void __init security_add_hooks(struct security_hook_list *hooks, int count,
-				char *lsm)
+			       struct lsm_id *lsmid)
 {
 	int i;
 
+	if (lsmid->slot == LSMBLOB_NEEDED) {
+		if (lsm_slot >= LSMBLOB_ENTRIES)
+			panic("%s Too many LSMs registered.\n", __func__);
+		lsmid->slot = lsm_slot++;
+		init_debug("%s assigned lsmblob slot %d\n", lsmid->lsm,
+			   lsmid->slot);
+	}
+
 	for (i = 0; i < count; i++) {
-		hooks[i].lsm = lsm;
+		hooks[i].lsmid = lsmid;
 		hlist_add_tail_rcu(&hooks[i].list, hooks[i].head);
 	}
-	if (lsm_append(lsm, &lsm_names) < 0)
+
+	if (lsm_append(lsmid->lsm, &lsm_names) < 0)
 		panic("%s - Cannot get early memory.\n", __func__);
 }
 
@@ -1917,7 +1934,7 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
 	struct security_hook_list *hp;
 
 	hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) {
-		if (lsm != NULL && strcmp(lsm, hp->lsm))
+		if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm))
 			continue;
 		return hp->hook.getprocattr(p, name, value);
 	}
@@ -1930,7 +1947,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
 	struct security_hook_list *hp;
 
 	hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) {
-		if (lsm != NULL && strcmp(lsm, hp->lsm))
+		if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm))
 			continue;
 		return hp->hook.setprocattr(name, value, size);
 	}
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index c83ec2652eda..74c491980ed2 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6622,6 +6622,11 @@ struct lsm_blob_sizes selinux_blob_sizes __lsm_ro_after_init = {
 	.lbs_superblock = sizeof(struct superblock_security_struct),
 };
 
+static struct lsm_id selinux_lsmid __lsm_ro_after_init = {
+	.lsm  = "selinux",
+	.slot = LSMBLOB_NEEDED
+};
+
 static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(binder_set_context_mgr, selinux_binder_set_context_mgr),
 	LSM_HOOK_INIT(binder_transaction, selinux_binder_transaction),
@@ -6877,7 +6882,8 @@ static __init int selinux_init(void)
 
 	hashtab_cache_init();
 
-	security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks), "selinux");
+	security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks),
+			   &selinux_lsmid);
 
 	if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET))
 		panic("SELinux: Unable to register AVC netcache callback\n");
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index e9560b078efe..7a0ead4da479 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -4553,6 +4553,11 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
 	.lbs_superblock = sizeof(struct superblock_smack),
 };
 
+static struct lsm_id smack_lsmid __lsm_ro_after_init = {
+	.lsm  = "smack",
+	.slot = LSMBLOB_NEEDED
+};
+
 static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(ptrace_access_check, smack_ptrace_access_check),
 	LSM_HOOK_INIT(ptrace_traceme, smack_ptrace_traceme),
@@ -4743,7 +4748,7 @@ static __init int smack_init(void)
 	/*
 	 * Register with LSM
 	 */
-	security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), "smack");
+	security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), &smack_lsmid);
 	smack_enabled = 1;
 
 	pr_info("Smack:  Initializing.\n");
diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c
index 716c92ec941a..f1968e80f06d 100644
--- a/security/tomoyo/tomoyo.c
+++ b/security/tomoyo/tomoyo.c
@@ -529,6 +529,11 @@ static void tomoyo_task_free(struct task_struct *task)
 	}
 }
 
+static struct lsm_id tomoyo_lsmid __lsm_ro_after_init = {
+	.lsm  = "tomoyo",
+	.slot = LSMBLOB_NOT_NEEDED
+};
+
 /*
  * tomoyo_security_ops is a "struct security_operations" which is used for
  * registering TOMOYO.
@@ -581,7 +586,8 @@ static int __init tomoyo_init(void)
 	struct tomoyo_task *s = tomoyo_task(current);
 
 	/* register ourselves with the security framework */
-	security_add_hooks(tomoyo_hooks, ARRAY_SIZE(tomoyo_hooks), "tomoyo");
+	security_add_hooks(tomoyo_hooks, ARRAY_SIZE(tomoyo_hooks),
+			   &tomoyo_lsmid);
 	pr_info("TOMOYO Linux initialized\n");
 	s->domain_info = &tomoyo_kernel_domain;
 	atomic_inc(&tomoyo_kernel_domain.users);
diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c
index efac68556b45..0529ecc86954 100644
--- a/security/yama/yama_lsm.c
+++ b/security/yama/yama_lsm.c
@@ -425,6 +425,11 @@ static int yama_ptrace_traceme(struct task_struct *parent)
 	return rc;
 }
 
+static struct lsm_id yama_lsmid __lsm_ro_after_init = {
+	.lsm  = "yama",
+	.slot = LSMBLOB_NOT_NEEDED
+};
+
 static struct security_hook_list yama_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(ptrace_access_check, yama_ptrace_access_check),
 	LSM_HOOK_INIT(ptrace_traceme, yama_ptrace_traceme),
@@ -482,7 +487,7 @@ static inline void yama_init_sysctl(void) { }
 static int __init yama_init(void)
 {
 	pr_info("Yama: becoming mindful.\n");
-	security_add_hooks(yama_hooks, ARRAY_SIZE(yama_hooks), "yama");
+	security_add_hooks(yama_hooks, ARRAY_SIZE(yama_hooks), &yama_lsmid);
 	yama_init_sysctl();
 	return 0;
 }
-- 
2.20.1


^ permalink raw reply related

* [PATCH v7 03/28] LSM: Infrastructure management of the key blob
From: Casey Schaufler @ 2019-08-07 19:43 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds
In-Reply-To: <20190807194410.9762-1-casey@schaufler-ca.com>

From: Casey Schaufler <cschaufler@schaufler-ca.com>

Move management of the key->security blob out of the
individual security modules and into the security
infrastructure. Instead of allocating the blobs from within
the modules the modules tell the infrastructure how much
space is required, and the space is allocated there.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <jojn.johansen@canonical.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/lsm_hooks.h         |  1 +
 security/security.c               | 40 ++++++++++++++++++++++++++++++-
 security/selinux/hooks.c          | 23 +++++-------------
 security/selinux/include/objsec.h |  7 ++++++
 security/smack/smack.h            |  7 ++++++
 security/smack/smack_lsm.c        | 33 ++++++++++++-------------
 6 files changed, 75 insertions(+), 36 deletions(-)

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index b353482ea348..3fe39abccc8f 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -2050,6 +2050,7 @@ struct lsm_blob_sizes {
 	int	lbs_sock;
 	int	lbs_superblock;
 	int	lbs_ipc;
+	int	lbs_key;
 	int	lbs_msg_msg;
 	int	lbs_task;
 };
diff --git a/security/security.c b/security/security.c
index 2c0834db7976..7cfedb90210a 100644
--- a/security/security.c
+++ b/security/security.c
@@ -172,6 +172,9 @@ static void __init lsm_set_blob_sizes(struct lsm_blob_sizes *needed)
 		blob_sizes.lbs_inode = sizeof(struct rcu_head);
 	lsm_set_blob_size(&needed->lbs_inode, &blob_sizes.lbs_inode);
 	lsm_set_blob_size(&needed->lbs_ipc, &blob_sizes.lbs_ipc);
+#ifdef CONFIG_KEYS
+	lsm_set_blob_size(&needed->lbs_key, &blob_sizes.lbs_key);
+#endif
 	lsm_set_blob_size(&needed->lbs_msg_msg, &blob_sizes.lbs_msg_msg);
 	lsm_set_blob_size(&needed->lbs_sock, &blob_sizes.lbs_sock);
 	lsm_set_blob_size(&needed->lbs_superblock, &blob_sizes.lbs_superblock);
@@ -307,6 +310,9 @@ static void __init ordered_lsm_init(void)
 	init_debug("file blob size       = %d\n", blob_sizes.lbs_file);
 	init_debug("inode blob size      = %d\n", blob_sizes.lbs_inode);
 	init_debug("ipc blob size        = %d\n", blob_sizes.lbs_ipc);
+#ifdef CONFIG_KEYS
+	init_debug("key blob size        = %d\n", blob_sizes.lbs_key);
+#endif /* CONFIG_KEYS */
 	init_debug("msg_msg blob size    = %d\n", blob_sizes.lbs_msg_msg);
 	init_debug("sock blob size       = %d\n", blob_sizes.lbs_sock);
 	init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock);
@@ -573,6 +579,29 @@ static int lsm_ipc_alloc(struct kern_ipc_perm *kip)
 	return 0;
 }
 
+#ifdef CONFIG_KEYS
+/**
+ * lsm_key_alloc - allocate a composite key blob
+ * @key: the key that needs a blob
+ *
+ * Allocate the key blob for all the modules
+ *
+ * Returns 0, or -ENOMEM if memory can't be allocated.
+ */
+static int lsm_key_alloc(struct key *key)
+{
+	if (blob_sizes.lbs_key == 0) {
+		key->security = NULL;
+		return 0;
+	}
+
+	key->security = kzalloc(blob_sizes.lbs_key, GFP_KERNEL);
+	if (key->security == NULL)
+		return -ENOMEM;
+	return 0;
+}
+#endif /* CONFIG_KEYS */
+
 /**
  * lsm_msg_msg_alloc - allocate a composite msg_msg blob
  * @mp: the msg_msg that needs a blob
@@ -2339,12 +2368,21 @@ EXPORT_SYMBOL(security_skb_classify_flow);
 int security_key_alloc(struct key *key, const struct cred *cred,
 		       unsigned long flags)
 {
-	return call_int_hook(key_alloc, 0, key, cred, flags);
+	int rc = lsm_key_alloc(key);
+
+	if (unlikely(rc))
+		return rc;
+	rc = call_int_hook(key_alloc, 0, key, cred, flags);
+	if (unlikely(rc))
+		security_key_free(key);
+	return rc;
 }
 
 void security_key_free(struct key *key)
 {
 	call_void_hook(key_free, key);
+	kfree(key->security);
+	key->security = NULL;
 }
 
 int security_key_permission(key_ref_t key_ref,
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 5d74ed35b728..c83ec2652eda 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6353,11 +6353,7 @@ static int selinux_key_alloc(struct key *k, const struct cred *cred,
 			     unsigned long flags)
 {
 	const struct task_security_struct *tsec;
-	struct key_security_struct *ksec;
-
-	ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
-	if (!ksec)
-		return -ENOMEM;
+	struct key_security_struct *ksec = selinux_key(k);
 
 	tsec = selinux_cred(cred);
 	if (tsec->keycreate_sid)
@@ -6365,18 +6361,9 @@ static int selinux_key_alloc(struct key *k, const struct cred *cred,
 	else
 		ksec->sid = tsec->sid;
 
-	k->security = ksec;
 	return 0;
 }
 
-static void selinux_key_free(struct key *k)
-{
-	struct key_security_struct *ksec = k->security;
-
-	k->security = NULL;
-	kfree(ksec);
-}
-
 static int selinux_key_permission(key_ref_t key_ref,
 				  const struct cred *cred,
 				  unsigned perm)
@@ -6394,7 +6381,7 @@ static int selinux_key_permission(key_ref_t key_ref,
 	sid = cred_sid(cred);
 
 	key = key_ref_to_ptr(key_ref);
-	ksec = key->security;
+	ksec = selinux_key(key);
 
 	return avc_has_perm(&selinux_state,
 			    sid, ksec->sid, SECCLASS_KEY, perm, NULL);
@@ -6402,7 +6389,7 @@ static int selinux_key_permission(key_ref_t key_ref,
 
 static int selinux_key_getsecurity(struct key *key, char **_buffer)
 {
-	struct key_security_struct *ksec = key->security;
+	struct key_security_struct *ksec = selinux_key(key);
 	char *context = NULL;
 	unsigned len;
 	int rc;
@@ -6627,6 +6614,9 @@ struct lsm_blob_sizes selinux_blob_sizes __lsm_ro_after_init = {
 	.lbs_file = sizeof(struct file_security_struct),
 	.lbs_inode = sizeof(struct inode_security_struct),
 	.lbs_ipc = sizeof(struct ipc_security_struct),
+#ifdef CONFIG_KEYS
+	.lbs_key = sizeof(struct key_security_struct),
+#endif /* CONFIG_KEYS */
 	.lbs_msg_msg = sizeof(struct msg_security_struct),
 	.lbs_sock = sizeof(struct sk_security_struct),
 	.lbs_superblock = sizeof(struct superblock_security_struct),
@@ -6842,7 +6832,6 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
 
 #ifdef CONFIG_KEYS
 	LSM_HOOK_INIT(key_alloc, selinux_key_alloc),
-	LSM_HOOK_INIT(key_free, selinux_key_free),
 	LSM_HOOK_INIT(key_permission, selinux_key_permission),
 	LSM_HOOK_INIT(key_getsecurity, selinux_key_getsecurity),
 #endif
diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h
index 29f02b8f8f31..3b78aa4ee98f 100644
--- a/security/selinux/include/objsec.h
+++ b/security/selinux/include/objsec.h
@@ -194,6 +194,13 @@ static inline struct superblock_security_struct *selinux_superblock(
 	return superblock->s_security + selinux_blob_sizes.lbs_superblock;
 }
 
+#ifdef CONFIG_KEYS
+static inline struct key_security_struct *selinux_key(const struct key *key)
+{
+	return key->security + selinux_blob_sizes.lbs_key;
+}
+#endif /* CONFIG_KEYS */
+
 static inline struct sk_security_struct *selinux_sock(const struct sock *sock)
 {
 	return sock->sk_security + selinux_blob_sizes.lbs_sock;
diff --git a/security/smack/smack.h b/security/smack/smack.h
index 4ac4bf3310d7..7cc3a3382fee 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -386,6 +386,13 @@ static inline struct superblock_smack *smack_superblock(
 	return superblock->s_security + smack_blob_sizes.lbs_superblock;
 }
 
+#ifdef CONFIG_KEYS
+static inline struct smack_known **smack_key(const struct key *key)
+{
+	return key->security + smack_blob_sizes.lbs_key;
+}
+#endif /* CONFIG_KEYS */
+
 /*
  * Is the directory transmuting?
  */
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index fd69e1bd841b..e9560b078efe 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -4179,23 +4179,13 @@ static void smack_inet_csk_clone(struct sock *sk,
 static int smack_key_alloc(struct key *key, const struct cred *cred,
 			   unsigned long flags)
 {
+	struct smack_known **blob = smack_key(key);
 	struct smack_known *skp = smk_of_task(smack_cred(cred));
 
-	key->security = skp;
+	*blob = skp;
 	return 0;
 }
 
-/**
- * smack_key_free - Clear the key security blob
- * @key: the object
- *
- * Clear the blob pointer
- */
-static void smack_key_free(struct key *key)
-{
-	key->security = NULL;
-}
-
 /**
  * smack_key_permission - Smack access on a key
  * @key_ref: gets to the object
@@ -4208,6 +4198,8 @@ static void smack_key_free(struct key *key)
 static int smack_key_permission(key_ref_t key_ref,
 				const struct cred *cred, unsigned perm)
 {
+	struct smack_known **blob;
+	struct smack_known *skp;
 	struct key *keyp;
 	struct smk_audit_info ad;
 	struct smack_known *tkp = smk_of_task(smack_cred(cred));
@@ -4227,7 +4219,9 @@ static int smack_key_permission(key_ref_t key_ref,
 	 * If the key hasn't been initialized give it access so that
 	 * it may do so.
 	 */
-	if (keyp->security == NULL)
+	blob = smack_key(keyp);
+	skp = *blob;
+	if (skp == NULL)
 		return 0;
 	/*
 	 * This should not occur
@@ -4247,8 +4241,8 @@ static int smack_key_permission(key_ref_t key_ref,
 		request |= MAY_READ;
 	if (perm & (KEY_NEED_WRITE | KEY_NEED_LINK | KEY_NEED_SETATTR))
 		request |= MAY_WRITE;
-	rc = smk_access(tkp, keyp->security, request, &ad);
-	rc = smk_bu_note("key access", tkp, keyp->security, request, rc);
+	rc = smk_access(tkp, skp, request, &ad);
+	rc = smk_bu_note("key access", tkp, skp, request, rc);
 	return rc;
 }
 
@@ -4263,11 +4257,12 @@ static int smack_key_permission(key_ref_t key_ref,
  */
 static int smack_key_getsecurity(struct key *key, char **_buffer)
 {
-	struct smack_known *skp = key->security;
+	struct smack_known **blob = smack_key(key);
+	struct smack_known *skp = *blob;
 	size_t length;
 	char *copy;
 
-	if (key->security == NULL) {
+	if (skp == NULL) {
 		*_buffer = NULL;
 		return 0;
 	}
@@ -4550,6 +4545,9 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
 	.lbs_file = sizeof(struct smack_known *),
 	.lbs_inode = sizeof(struct inode_smack),
 	.lbs_ipc = sizeof(struct smack_known *),
+#ifdef CONFIG_KEYS
+	.lbs_key = sizeof(struct smack_known *),
+#endif /* CONFIG_KEYS */
 	.lbs_msg_msg = sizeof(struct smack_known *),
 	.lbs_sock = sizeof(struct socket_smack),
 	.lbs_superblock = sizeof(struct superblock_smack),
@@ -4671,7 +4669,6 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
  /* key management security hooks */
 #ifdef CONFIG_KEYS
 	LSM_HOOK_INIT(key_alloc, smack_key_alloc),
-	LSM_HOOK_INIT(key_free, smack_key_free),
 	LSM_HOOK_INIT(key_permission, smack_key_permission),
 	LSM_HOOK_INIT(key_getsecurity, smack_key_getsecurity),
 #endif /* CONFIG_KEYS */
-- 
2.20.1


^ permalink raw reply related

* [PATCH v7 01/28] LSM: Infrastructure management of the superblock
From: Casey Schaufler @ 2019-08-07 19:43 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds
In-Reply-To: <20190807194410.9762-1-casey@schaufler-ca.com>

Move management of the superblock->sb_security blob out
of the individual security modules and into the security
infrastructure. Instead of allocating the blobs from within
the modules the modules tell the infrastructure how much
space is required, and the space is allocated there.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/lsm_hooks.h         |  1 +
 security/security.c               | 46 ++++++++++++++++++++----
 security/selinux/hooks.c          | 58 ++++++++++++-------------------
 security/selinux/include/objsec.h |  6 ++++
 security/selinux/ss/services.c    |  3 +-
 security/smack/smack.h            |  6 ++++
 security/smack/smack_lsm.c        | 35 +++++--------------
 7 files changed, 85 insertions(+), 70 deletions(-)

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index a240a3fc5fc4..f9222a04968d 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -2047,6 +2047,7 @@ struct lsm_blob_sizes {
 	int	lbs_cred;
 	int	lbs_file;
 	int	lbs_inode;
+	int	lbs_superblock;
 	int	lbs_ipc;
 	int	lbs_msg_msg;
 	int	lbs_task;
diff --git a/security/security.c b/security/security.c
index 23cbb1a295a3..86198e303203 100644
--- a/security/security.c
+++ b/security/security.c
@@ -172,6 +172,7 @@ static void __init lsm_set_blob_sizes(struct lsm_blob_sizes *needed)
 	lsm_set_blob_size(&needed->lbs_inode, &blob_sizes.lbs_inode);
 	lsm_set_blob_size(&needed->lbs_ipc, &blob_sizes.lbs_ipc);
 	lsm_set_blob_size(&needed->lbs_msg_msg, &blob_sizes.lbs_msg_msg);
+	lsm_set_blob_size(&needed->lbs_superblock, &blob_sizes.lbs_superblock);
 	lsm_set_blob_size(&needed->lbs_task, &blob_sizes.lbs_task);
 }
 
@@ -300,12 +301,13 @@ static void __init ordered_lsm_init(void)
 	for (lsm = ordered_lsms; *lsm; lsm++)
 		prepare_lsm(*lsm);
 
-	init_debug("cred blob size     = %d\n", blob_sizes.lbs_cred);
-	init_debug("file blob size     = %d\n", blob_sizes.lbs_file);
-	init_debug("inode blob size    = %d\n", blob_sizes.lbs_inode);
-	init_debug("ipc blob size      = %d\n", blob_sizes.lbs_ipc);
-	init_debug("msg_msg blob size  = %d\n", blob_sizes.lbs_msg_msg);
-	init_debug("task blob size     = %d\n", blob_sizes.lbs_task);
+	init_debug("cred blob size       = %d\n", blob_sizes.lbs_cred);
+	init_debug("file blob size       = %d\n", blob_sizes.lbs_file);
+	init_debug("inode blob size      = %d\n", blob_sizes.lbs_inode);
+	init_debug("ipc blob size        = %d\n", blob_sizes.lbs_ipc);
+	init_debug("msg_msg blob size    = %d\n", blob_sizes.lbs_msg_msg);
+	init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock);
+	init_debug("task blob size       = %d\n", blob_sizes.lbs_task);
 
 	/*
 	 * Create any kmem_caches needed for blobs
@@ -603,6 +605,27 @@ static void __init lsm_early_task(struct task_struct *task)
 		panic("%s: Early task alloc failed.\n", __func__);
 }
 
+/**
+ * lsm_superblock_alloc - allocate a composite superblock blob
+ * @sb: the superblock that needs a blob
+ *
+ * Allocate the superblock blob for all the modules
+ *
+ * Returns 0, or -ENOMEM if memory can't be allocated.
+ */
+static int lsm_superblock_alloc(struct super_block *sb)
+{
+	if (blob_sizes.lbs_superblock == 0) {
+		sb->s_security = NULL;
+		return 0;
+	}
+
+	sb->s_security = kzalloc(blob_sizes.lbs_superblock, GFP_KERNEL);
+	if (sb->s_security == NULL)
+		return -ENOMEM;
+	return 0;
+}
+
 /*
  * Hook list operation macros.
  *
@@ -776,12 +799,21 @@ int security_fs_context_parse_param(struct fs_context *fc, struct fs_parameter *
 
 int security_sb_alloc(struct super_block *sb)
 {
-	return call_int_hook(sb_alloc_security, 0, sb);
+	int rc = lsm_superblock_alloc(sb);
+
+	if (unlikely(rc))
+		return rc;
+	rc = call_int_hook(sb_alloc_security, 0, sb);
+	if (unlikely(rc))
+		security_sb_free(sb);
+	return rc;
 }
 
 void security_sb_free(struct super_block *sb)
 {
 	call_void_hook(sb_free_security, sb);
+	kfree(sb->s_security);
+	sb->s_security = NULL;
 }
 
 void security_free_mnt_opts(void **mnt_opts)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 1d0b37af2444..7478d8eda00a 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -335,7 +335,7 @@ static void inode_free_security(struct inode *inode)
 
 	if (!isec)
 		return;
-	sbsec = inode->i_sb->s_security;
+	sbsec = selinux_superblock(inode->i_sb);
 	/*
 	 * As not all inode security structures are in a list, we check for
 	 * empty list outside of the lock to make sure that we won't waste
@@ -366,11 +366,7 @@ static int file_alloc_security(struct file *file)
 
 static int superblock_alloc_security(struct super_block *sb)
 {
-	struct superblock_security_struct *sbsec;
-
-	sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
-	if (!sbsec)
-		return -ENOMEM;
+	struct superblock_security_struct *sbsec = selinux_superblock(sb);
 
 	mutex_init(&sbsec->lock);
 	INIT_LIST_HEAD(&sbsec->isec_head);
@@ -379,18 +375,10 @@ static int superblock_alloc_security(struct super_block *sb)
 	sbsec->sid = SECINITSID_UNLABELED;
 	sbsec->def_sid = SECINITSID_FILE;
 	sbsec->mntpoint_sid = SECINITSID_UNLABELED;
-	sb->s_security = sbsec;
 
 	return 0;
 }
 
-static void superblock_free_security(struct super_block *sb)
-{
-	struct superblock_security_struct *sbsec = sb->s_security;
-	sb->s_security = NULL;
-	kfree(sbsec);
-}
-
 struct selinux_mnt_opts {
 	const char *fscontext, *context, *rootcontext, *defcontext;
 };
@@ -507,7 +495,7 @@ static int selinux_is_genfs_special_handling(struct super_block *sb)
 
 static int selinux_is_sblabel_mnt(struct super_block *sb)
 {
-	struct superblock_security_struct *sbsec = sb->s_security;
+	struct superblock_security_struct *sbsec = selinux_superblock(sb);
 
 	/*
 	 * IMPORTANT: Double-check logic in this function when adding a new
@@ -535,7 +523,7 @@ static int selinux_is_sblabel_mnt(struct super_block *sb)
 
 static int sb_finish_set_opts(struct super_block *sb)
 {
-	struct superblock_security_struct *sbsec = sb->s_security;
+	struct superblock_security_struct *sbsec = selinux_superblock(sb);
 	struct dentry *root = sb->s_root;
 	struct inode *root_inode = d_backing_inode(root);
 	int rc = 0;
@@ -648,7 +636,7 @@ static int selinux_set_mnt_opts(struct super_block *sb,
 				unsigned long *set_kern_flags)
 {
 	const struct cred *cred = current_cred();
-	struct superblock_security_struct *sbsec = sb->s_security;
+	struct superblock_security_struct *sbsec = selinux_superblock(sb);
 	struct dentry *root = sbsec->sb->s_root;
 	struct selinux_mnt_opts *opts = mnt_opts;
 	struct inode_security_struct *root_isec;
@@ -881,8 +869,8 @@ static int selinux_set_mnt_opts(struct super_block *sb,
 static int selinux_cmp_sb_context(const struct super_block *oldsb,
 				    const struct super_block *newsb)
 {
-	struct superblock_security_struct *old = oldsb->s_security;
-	struct superblock_security_struct *new = newsb->s_security;
+	struct superblock_security_struct *old = selinux_superblock(oldsb);
+	struct superblock_security_struct *new = selinux_superblock(newsb);
 	char oldflags = old->flags & SE_MNTMASK;
 	char newflags = new->flags & SE_MNTMASK;
 
@@ -914,8 +902,9 @@ static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
 					unsigned long *set_kern_flags)
 {
 	int rc = 0;
-	const struct superblock_security_struct *oldsbsec = oldsb->s_security;
-	struct superblock_security_struct *newsbsec = newsb->s_security;
+	const struct superblock_security_struct *oldsbsec =
+						selinux_superblock(oldsb);
+	struct superblock_security_struct *newsbsec = selinux_superblock(newsb);
 
 	int set_fscontext =	(oldsbsec->flags & FSCONTEXT_MNT);
 	int set_context =	(oldsbsec->flags & CONTEXT_MNT);
@@ -1085,7 +1074,7 @@ static int show_sid(struct seq_file *m, u32 sid)
 
 static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
 {
-	struct superblock_security_struct *sbsec = sb->s_security;
+	struct superblock_security_struct *sbsec = selinux_superblock(sb);
 	int rc;
 
 	if (!(sbsec->flags & SE_SBINITIALIZED))
@@ -1377,7 +1366,7 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
 	if (isec->sclass == SECCLASS_FILE)
 		isec->sclass = inode_mode_to_security_class(inode->i_mode);
 
-	sbsec = inode->i_sb->s_security;
+	sbsec = selinux_superblock(inode->i_sb);
 	if (!(sbsec->flags & SE_SBINITIALIZED)) {
 		/* Defer initialization until selinux_complete_init,
 		   after the initial policy is loaded and the security
@@ -1767,7 +1756,8 @@ selinux_determine_inode_label(const struct task_security_struct *tsec,
 				 const struct qstr *name, u16 tclass,
 				 u32 *_new_isid)
 {
-	const struct superblock_security_struct *sbsec = dir->i_sb->s_security;
+	const struct superblock_security_struct *sbsec =
+						selinux_superblock(dir->i_sb);
 
 	if ((sbsec->flags & SE_SBINITIALIZED) &&
 	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) {
@@ -1798,7 +1788,7 @@ static int may_create(struct inode *dir,
 	int rc;
 
 	dsec = inode_security(dir);
-	sbsec = dir->i_sb->s_security;
+	sbsec = selinux_superblock(dir->i_sb);
 
 	sid = tsec->sid;
 
@@ -1947,7 +1937,7 @@ static int superblock_has_perm(const struct cred *cred,
 	struct superblock_security_struct *sbsec;
 	u32 sid = cred_sid(cred);
 
-	sbsec = sb->s_security;
+	sbsec = selinux_superblock(sb);
 	return avc_has_perm(&selinux_state,
 			    sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
 }
@@ -2578,11 +2568,6 @@ static int selinux_sb_alloc_security(struct super_block *sb)
 	return superblock_alloc_security(sb);
 }
 
-static void selinux_sb_free_security(struct super_block *sb)
-{
-	superblock_free_security(sb);
-}
-
 static inline int opt_len(const char *s)
 {
 	bool open_quote = false;
@@ -2653,7 +2638,7 @@ static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts)
 static int selinux_sb_remount(struct super_block *sb, void *mnt_opts)
 {
 	struct selinux_mnt_opts *opts = mnt_opts;
-	struct superblock_security_struct *sbsec = sb->s_security;
+	struct superblock_security_struct *sbsec = selinux_superblock(sb);
 	u32 sid;
 	int rc;
 
@@ -2877,7 +2862,7 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
 	int rc;
 	char *context;
 
-	sbsec = dir->i_sb->s_security;
+	sbsec = selinux_superblock(dir->i_sb);
 
 	newsid = tsec->create_sid;
 
@@ -3115,7 +3100,7 @@ static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
 		return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
 	}
 
-	sbsec = inode->i_sb->s_security;
+	sbsec = selinux_superblock(inode->i_sb);
 	if (!(sbsec->flags & SBLABEL_MNT))
 		return -EOPNOTSUPP;
 
@@ -3296,13 +3281,14 @@ static int selinux_inode_setsecurity(struct inode *inode, const char *name,
 				     const void *value, size_t size, int flags)
 {
 	struct inode_security_struct *isec = inode_security_novalidate(inode);
-	struct superblock_security_struct *sbsec = inode->i_sb->s_security;
+	struct superblock_security_struct *sbsec;
 	u32 newsid;
 	int rc;
 
 	if (strcmp(name, XATTR_SELINUX_SUFFIX))
 		return -EOPNOTSUPP;
 
+	sbsec = selinux_superblock(inode->i_sb);
 	if (!(sbsec->flags & SBLABEL_MNT))
 		return -EOPNOTSUPP;
 
@@ -6647,6 +6633,7 @@ struct lsm_blob_sizes selinux_blob_sizes __lsm_ro_after_init = {
 	.lbs_inode = sizeof(struct inode_security_struct),
 	.lbs_ipc = sizeof(struct ipc_security_struct),
 	.lbs_msg_msg = sizeof(struct msg_security_struct),
+	.lbs_superblock = sizeof(struct superblock_security_struct),
 };
 
 static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
@@ -6675,7 +6662,6 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(fs_context_parse_param, selinux_fs_context_parse_param),
 
 	LSM_HOOK_INIT(sb_alloc_security, selinux_sb_alloc_security),
-	LSM_HOOK_INIT(sb_free_security, selinux_sb_free_security),
 	LSM_HOOK_INIT(sb_eat_lsm_opts, selinux_sb_eat_lsm_opts),
 	LSM_HOOK_INIT(sb_free_mnt_opts, selinux_free_mnt_opts),
 	LSM_HOOK_INIT(sb_remount, selinux_sb_remount),
diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h
index 231262d8eac9..d08d7e5d2f93 100644
--- a/security/selinux/include/objsec.h
+++ b/security/selinux/include/objsec.h
@@ -188,4 +188,10 @@ static inline struct ipc_security_struct *selinux_ipc(
 	return ipc->security + selinux_blob_sizes.lbs_ipc;
 }
 
+static inline struct superblock_security_struct *selinux_superblock(
+					const struct super_block *superblock)
+{
+	return superblock->s_security + selinux_blob_sizes.lbs_superblock;
+}
+
 #endif /* _SELINUX_OBJSEC_H_ */
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index ec62918521b1..e3f5d6aece66 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -50,6 +50,7 @@
 #include <linux/audit.h>
 #include <linux/mutex.h>
 #include <linux/vmalloc.h>
+#include <linux/lsm_hooks.h>
 #include <net/netlabel.h>
 
 #include "flask.h"
@@ -2751,7 +2752,7 @@ int security_fs_use(struct selinux_state *state, struct super_block *sb)
 	struct sidtab *sidtab;
 	int rc = 0;
 	struct ocontext *c;
-	struct superblock_security_struct *sbsec = sb->s_security;
+	struct superblock_security_struct *sbsec = selinux_superblock(sb);
 	const char *fstype = sb->s_type->name;
 
 	read_lock(&state->ss->policy_rwlock);
diff --git a/security/smack/smack.h b/security/smack/smack.h
index cf52af77d15e..caecbcba9942 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -375,6 +375,12 @@ static inline struct smack_known **smack_ipc(const struct kern_ipc_perm *ipc)
 	return ipc->security + smack_blob_sizes.lbs_ipc;
 }
 
+static inline struct superblock_smack *smack_superblock(
+					const struct super_block *superblock)
+{
+	return superblock->s_security + smack_blob_sizes.lbs_superblock;
+}
+
 /*
  * Is the directory transmuting?
  */
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 5c1613519d5a..807eff2ccce9 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -540,12 +540,7 @@ static int smack_syslog(int typefrom_file)
  */
 static int smack_sb_alloc_security(struct super_block *sb)
 {
-	struct superblock_smack *sbsp;
-
-	sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);
-
-	if (sbsp == NULL)
-		return -ENOMEM;
+	struct superblock_smack *sbsp = smack_superblock(sb);
 
 	sbsp->smk_root = &smack_known_floor;
 	sbsp->smk_default = &smack_known_floor;
@@ -554,22 +549,10 @@ static int smack_sb_alloc_security(struct super_block *sb)
 	/*
 	 * SMK_SB_INITIALIZED will be zero from kzalloc.
 	 */
-	sb->s_security = sbsp;
 
 	return 0;
 }
 
-/**
- * smack_sb_free_security - free a superblock blob
- * @sb: the superblock getting the blob
- *
- */
-static void smack_sb_free_security(struct super_block *sb)
-{
-	kfree(sb->s_security);
-	sb->s_security = NULL;
-}
-
 struct smack_mnt_opts {
 	const char *fsdefault, *fsfloor, *fshat, *fsroot, *fstransmute;
 };
@@ -781,7 +764,7 @@ static int smack_set_mnt_opts(struct super_block *sb,
 {
 	struct dentry *root = sb->s_root;
 	struct inode *inode = d_backing_inode(root);
-	struct superblock_smack *sp = sb->s_security;
+	struct superblock_smack *sp = smack_superblock(sb);
 	struct inode_smack *isp;
 	struct smack_known *skp;
 	struct smack_mnt_opts *opts = mnt_opts;
@@ -880,7 +863,7 @@ static int smack_set_mnt_opts(struct super_block *sb,
  */
 static int smack_sb_statfs(struct dentry *dentry)
 {
-	struct superblock_smack *sbp = dentry->d_sb->s_security;
+	struct superblock_smack *sbp = smack_superblock(dentry->d_sb);
 	int rc;
 	struct smk_audit_info ad;
 
@@ -917,7 +900,7 @@ static int smack_bprm_set_creds(struct linux_binprm *bprm)
 	if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
 		return 0;
 
-	sbsp = inode->i_sb->s_security;
+	sbsp = smack_superblock(inode->i_sb);
 	if ((sbsp->smk_flags & SMK_SB_UNTRUSTED) &&
 	    isp->smk_task != sbsp->smk_root)
 		return 0;
@@ -1168,7 +1151,7 @@ static int smack_inode_rename(struct inode *old_inode,
  */
 static int smack_inode_permission(struct inode *inode, int mask)
 {
-	struct superblock_smack *sbsp = inode->i_sb->s_security;
+	struct superblock_smack *sbsp = smack_superblock(inode->i_sb);
 	struct smk_audit_info ad;
 	int no_block = mask & MAY_NOT_BLOCK;
 	int rc;
@@ -1410,7 +1393,7 @@ static int smack_inode_removexattr(struct dentry *dentry, const char *name)
 	 */
 	if (strcmp(name, XATTR_NAME_SMACK) == 0) {
 		struct super_block *sbp = dentry->d_sb;
-		struct superblock_smack *sbsp = sbp->s_security;
+		struct superblock_smack *sbsp = smack_superblock(sbp);
 
 		isp->smk_inode = sbsp->smk_default;
 	} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0)
@@ -1680,7 +1663,7 @@ static int smack_mmap_file(struct file *file,
 	isp = smack_inode(file_inode(file));
 	if (isp->smk_mmap == NULL)
 		return 0;
-	sbsp = file_inode(file)->i_sb->s_security;
+	sbsp = smack_superblock(file_inode(file)->i_sb);
 	if (sbsp->smk_flags & SMK_SB_UNTRUSTED &&
 	    isp->smk_mmap != sbsp->smk_root)
 		return -EACCES;
@@ -3288,7 +3271,7 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
 		goto unlockandout;
 
 	sbp = inode->i_sb;
-	sbsp = sbp->s_security;
+	sbsp = smack_superblock(sbp);
 	/*
 	 * We're going to use the superblock default label
 	 * if there's no label on the file.
@@ -4575,6 +4558,7 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
 	.lbs_inode = sizeof(struct inode_smack),
 	.lbs_ipc = sizeof(struct smack_known *),
 	.lbs_msg_msg = sizeof(struct smack_known *),
+	.lbs_superblock = sizeof(struct superblock_smack),
 };
 
 static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
@@ -4586,7 +4570,6 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(fs_context_parse_param, smack_fs_context_parse_param),
 
 	LSM_HOOK_INIT(sb_alloc_security, smack_sb_alloc_security),
-	LSM_HOOK_INIT(sb_free_security, smack_sb_free_security),
 	LSM_HOOK_INIT(sb_free_mnt_opts, smack_free_mnt_opts),
 	LSM_HOOK_INIT(sb_eat_lsm_opts, smack_sb_eat_lsm_opts),
 	LSM_HOOK_INIT(sb_statfs, smack_sb_statfs),
-- 
2.20.1


^ permalink raw reply related

* [PATCH v7 00/28] LSM: Module stacking for AppArmor
From: Casey Schaufler @ 2019-08-07 19:43 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

This patchset provides the changes required for
the AppArmor security module to stack safely with any other.

v7: Incorporate feedback from v6
    - Make setting the display a privileged operation. The
      availability of compound contexts reduces the need for
      setting the display.

v6: Incorporate feedback from v5
    - Add subj_<lsm>= and obj_<lsm>= fields to audit records
    - Add /proc/.../attr/context to get the full context in
      lsmname\0value\0... format as suggested by Simon McVittie
    - Add SO_PEERCONTEXT for getsockopt() to get the full context
      in the same format, also suggested by Simon McVittie.
    - Add /sys/kernel/security/lsm_display_default to provide
      the display default value.

v5: Incorporate feedback from v4
    - Initialize the lsmcontext in security_secid_to_secctx()
    - Clear the lsmcontext in all security_release_secctx() cases
    - Don't use the "display" on strictly internal context
      interfaces.
    - The SELinux binder hooks check for cases where the context
      "display" isn't compatible with SELinux.

v4: Incorporate feedback from v3
    - Mark new lsm_<blob>_alloc functions static
    - Replace the lsm and slot fields of the security_hook_list
      with a pointer to a LSM allocated lsm_id structure. The
      LSM identifies if it needs a slot explicitly. Use the
      lsm_id rather than make security_add_hooks return the
      slot value.
    - Validate slot values used in security.c
    - Reworked the "display" process attribute handling so that
      it works right and doesn't use goofy list processing.
    - fix display value check in dentry_init_security
    - Replace audit_log of secids with '?' instead of deleting
      the audit log

v3: Incorporate feedback from v2
    - Make lsmblob parameter and variable names more
      meaningful, changing "le" and "l" to "blob".
    - Improve consistency of constant naming.
    - Do more sanity checking during LSM initialization.
    - Be a bit clearer about what is temporary scaffolding.
    - Rather than clutter security_getpeersec_dgram with
      otherwise unnecessary checks remove the apparmor
      stub, which does nothing useful.

Patches 0001-0003 complete the process of moving management
of security blobs that might be shared from the individual
modules to the infrastructure.

Patches 0004-0014 replace system use of a "secid" with
a structure "lsmblob" containing information from the
security modules to be held and reused later. At this
point lsmblob contains an array of u32 secids, one "slot"
for each of the security modules compiled into the
kernel that used secids. A "slot" is allocated when
a security module requests one.
The infrastructure is changed to use the slot number
to pass the correct secid to or from the security module
hooks.

It is important that the lsmblob be a fixed size entity
that does not have to be allocated. Several of the places
where it is used would have performance and/or locking
issues with dynamic allocation.

Patch 0015 provides a mechanism for a process to
identify which security module's hooks should be used
when displaying or converting a security context string.
A new interface /proc/.../attr/display contains the name
of the security module to show. Reading from this file
will present the name of the module, while writing to
it will set the value. Only names of active security
modules are accepted. Internally, the name is translated
to the appropriate "slot" number for the module which
is then stored in the task security blob. Setting the
display requires CAP_MAC_ADMIN.

Patch 0016 Starts the process of changing how a security
context is represented. Since it is possible for a
security context to have been generated by more than one
security module it is now necessary to note which module
created a security context so that the correct "release"
hook can be called. There are several places where the
module that created a security context cannot be inferred.

This is achieved by introducing a "lsmcontext" structure
which contains the context string, its length and the
"slot" number of the security module that created it.
The security_release_secctx() interface is changed,
replacing the (string,len) pointer pair with a lsmcontext
pointer.

Patches 0017-0019 convert the security interfaces from
(string,len) pointer pairs to a lsmcontext pointer.
The slot number identifying the creating module is
added by the infrastructure. Where the security context
is stored for extended periods the data type is changed.

The Netlabel code is converted to save lsmblob structures
instead of secids in Patches 0020-21.

Patch 0022 adds checks to the SELinux binder hooks
which verify that if either "display" used is SELinux
both are.

Patches 0023-24 add addition data to the audit records
to identify the LSM specific data for all active
modules.

Patches 0025-0027 add new interfaces for getting the
compound security contexts.

Finally, with all interference on the AppArmor hooks
removed, Patch 0028 removes the exclusive bit from
AppArmor. An unnecessary stub hook was also removed.

The Ubuntu project is using an earlier version of
this patchset in their distribution to enable stacking
for containers.

Performance measurements to date have the change
within the "noise". The sockperf and dbench results
are on the order of 0.2% to 0.8% difference, with
better performance being as common as worse. The
benchmarks were run with AppArmor and Smack on Ubuntu.

https://github.com/cschaufler/lsm-stacking.git#stack-5.2-v7-apparmor

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 arch/alpha/include/uapi/asm/socket.h    |   1 +
 arch/mips/include/uapi/asm/socket.h     |   1 +
 arch/parisc/include/uapi/asm/socket.h   |   1 +
 arch/sparc/include/uapi/asm/socket.h    |   1 +
 drivers/android/binder.c                |  24 +-
 fs/kernfs/dir.c                         |   5 +-
 fs/kernfs/inode.c                       |  35 +-
 fs/kernfs/kernfs-internal.h             |   3 +-
 fs/nfs/nfs4proc.c                       |  22 +-
 fs/nfsd/nfs4xdr.c                       |  20 +-
 fs/proc/base.c                          |   2 +
 include/linux/audit.h                   |   1 +
 include/linux/cred.h                    |   3 +-
 include/linux/lsm_hooks.h               |  39 +-
 include/linux/security.h                | 184 ++++++++--
 include/net/af_unix.h                   |   2 +-
 include/net/netlabel.h                  |   8 +-
 include/net/scm.h                       |  15 +-
 include/uapi/asm-generic/socket.h       |   1 +
 kernel/audit.c                          |  70 +++-
 kernel/audit.h                          |   9 +-
 kernel/audit_fsnotify.c                 |   1 +
 kernel/auditfilter.c                    |  10 +-
 kernel/auditsc.c                        | 129 ++++---
 kernel/cred.c                           |  12 +-
 net/core/sock.c                         |   7 +-
 net/ipv4/cipso_ipv4.c                   |   6 +-
 net/ipv4/ip_sockglue.c                  |  12 +-
 net/netfilter/nf_conntrack_netlink.c    |  20 +-
 net/netfilter/nf_conntrack_standalone.c |  11 +-
 net/netfilter/nfnetlink_queue.c         |  26 +-
 net/netfilter/nft_meta.c                |  13 +-
 net/netfilter/xt_SECMARK.c              |   5 +-
 net/netlabel/netlabel_kapi.c            |   6 +-
 net/netlabel/netlabel_unlabeled.c       |  98 ++---
 net/netlabel/netlabel_unlabeled.h       |   2 +-
 net/netlabel/netlabel_user.c            |  13 +-
 net/netlabel/netlabel_user.h            |   6 +-
 net/unix/af_unix.c                      |   6 +-
 net/xfrm/xfrm_policy.c                  |   2 +
 net/xfrm/xfrm_state.c                   |   2 +
 security/apparmor/include/net.h         |   6 +-
 security/apparmor/lsm.c                 |  85 ++---
 security/commoncap.c                    |   7 +-
 security/inode.c                        |  22 +-
 security/integrity/ima/ima.h            |  14 +-
 security/integrity/ima/ima_api.c        |  10 +-
 security/integrity/ima/ima_appraise.c   |   6 +-
 security/integrity/ima/ima_main.c       |  36 +-
 security/integrity/ima/ima_policy.c     |  19 +-
 security/integrity/integrity_audit.c    |   1 +
 security/loadpin/loadpin.c              |   8 +-
 security/safesetid/lsm.c                |   8 +-
 security/security.c                     | 619 +++++++++++++++++++++++++++++---
 security/selinux/hooks.c                | 213 +++++------
 security/selinux/include/objsec.h       |  18 +
 security/selinux/include/security.h     |   1 +
 security/selinux/netlabel.c             |  25 +-
 security/selinux/ss/services.c          |   7 +-
 security/smack/smack.h                  |  19 +
 security/smack/smack_lsm.c              | 185 +++++-----
 security/smack/smack_netfilter.c        |   8 +-
 security/smack/smackfs.c                |  10 +-
 security/tomoyo/tomoyo.c                |   8 +-
 security/yama/yama_lsm.c                |   7 +-
 65 files changed, 1490 insertions(+), 686 deletions(-)

^ permalink raw reply

* Re: [GIT PULL] SafeSetID MAINTAINERS file update for v5.3
From: Linus Torvalds @ 2019-08-07 19:27 UTC (permalink / raw)
  To: Micah Morton
  Cc: Konstantin Ryabitsev, linux-security-module,
	Linux Kernel Mailing List
In-Reply-To: <CAJ-EccPFnR7fTFee3s_1Er+-zbhD8AqaJu_ifTLwHUykKmwJLg@mail.gmail.com>

On Tue, Aug 6, 2019 at 9:32 AM Micah Morton <mortonm@chromium.org> wrote:
>
> Unfortunately I didn't have the mental model quite right of what
> happens during the pull request. I was thinking along the lines of my
> commits being cherry picked onto your tree, rather than how it
> actually happens with git merge where my tree's commit history needs
> to match yours perfectly.

The "cherry-pick" model is what "git pull --rebase" does in reverse
(ie it pulls the exact history from the other end, and then rebases
the _local_ history on top of that).

But the cherry-picking model is entirely inappropriate for any bigger
project. Yes, you can do it locally on your _local_ small changes (but
see all the docs about why rebasing is not a great thing), but it's
entirely unmanageable and doesn't scale in the big picture.

It's why all the projects that were based on patch series were
complete and utter failures. A "patch series" only works locally. It's
not reasonable to scale and distribute.

Git fundamentally makes history a first-class immutable citizen, and
it's a major feature and a core design thing, and it's the _only_
thing that makes distribution possible. Whenever you rewrite history,
you fundamentally screw up a distributed model.

             Linus

^ permalink raw reply

* Re: [RFC/RFT v3 2/3] KEYS: trusted: move tpm2 trusted keys code
From: Jarkko Sakkinen @ 2019-08-07 19:03 UTC (permalink / raw)
  To: Sumit Garg
  Cc: keyrings, linux-integrity, linux-crypto, linux-security-module,
	dhowells, herbert, davem, peterhuewe, jgg, jejb, arnd, gregkh,
	zohar, jmorris, serge, casey, ard.biesheuvel, daniel.thompson,
	linux-kernel, tee-dev
In-Reply-To: <1565098640-12536-3-git-send-email-sumit.garg@linaro.org>

On Tue, Aug 06, 2019 at 07:07:19PM +0530, Sumit Garg wrote:
> Move TPM2 trusted keys code to trusted keys subsystem.

Missing a long description. The reason is that it is better consolidate
all trusted keys code to a single location so that it can be maintained
sanely and it should be stated here.

> Suggested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> Signed-off-by: Sumit Garg <sumit.garg@linaro.org>

I would suggest adding at least two commits before this:

- A commit that just exports tpm_buf stuff and TPM2 constants to
  include/linux
- A commit that just changes the existing TPM 1.x trusted keys
  code to use tpm_buf.

These should be before the current 1/3 commit.

/Jarkko

^ permalink raw reply

* Re: [RFC/RFT v3 1/3] KEYS: trusted: create trusted keys subsystem
From: Jarkko Sakkinen @ 2019-08-07 18:59 UTC (permalink / raw)
  To: Sumit Garg
  Cc: keyrings, linux-integrity, linux-crypto, linux-security-module,
	dhowells, herbert, davem, peterhuewe, jgg, jejb, arnd, gregkh,
	zohar, jmorris, serge, casey, ard.biesheuvel, daniel.thompson,
	linux-kernel, tee-dev
In-Reply-To: <1565098640-12536-2-git-send-email-sumit.garg@linaro.org>

On Tue, Aug 06, 2019 at 07:07:18PM +0530, Sumit Garg wrote:
> Move existing code to trusted keys subsystem. Also, rename files with
> "tpm" as suffix which provides the underlying implementation.
> 
> Suggested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> Signed-off-by: Sumit Garg <sumit.garg@linaro.org>

The name for should be still trusted.ko even if new backends are added.
Must be done in order not to break user space.

Situation is quite similar as when new backends were added to tpm_tis
some time ago: MMIO backed implementation was kept as tpm_tis.ko, the
core module was named as tpm_tis_core and SPI backed implementation was
named as tpm_tis_spi.ko.

/Jarkko

^ permalink raw reply

* Re: [RFC PATCH v3 04/12] x86/sgx: Require userspace to define enclave pages' protection bits
From: Jarkko Sakkinen @ 2019-08-07 18:51 UTC (permalink / raw)
  To: Andy Lutomirski
  Cc: Sean Christopherson, Schaufler, Casey, James Morris, linux-sgx,
	Dave Hansen, Cedric Xing, Jethro Beekman, Dr . Greg Wettstein,
	Stephen Smalley, LSM List
In-Reply-To: <CALCETrVcaL5KfR0V2fiHzQtyQdEC7d9iFNDKp9yBj7QZQsdXyw@mail.gmail.com>

On Mon, Aug 05, 2019 at 02:30:22PM -0700, Andy Lutomirski wrote:
> On Mon, Aug 5, 2019 at 1:51 PM Jarkko Sakkinen
> <jarkko.sakkinen@linux.intel.com> wrote:
> >
> > On Sun, Aug 04, 2019 at 03:20:24PM -0700, Andy Lutomirski wrote:
> > > On Thu, Aug 1, 2019 at 9:38 AM Jarkko Sakkinen
> > > <jarkko.sakkinen@linux.intel.com> wrote:
> > > >
> > > > On Mon, Jul 15, 2019 at 03:29:23PM -0700, Andy Lutomirski wrote:
> > > > > I would say it differently: regardless of exactly how /dev/sgx/enclave
> > > > > is wired up under the hood, we want a way that a process can be
> > > > > granted permission to usefully run enclaves without being granted
> > > > > permission to execute whatever bytes of code it wants.  Preferably
> > > > > without requiring LSMs to maintain some form of enclave signature
> > > > > whitelist.
> > > >
> > > > Would it be better to have a signer whitelist instead or some
> > > > combination? E.g. you could whiteliste either by signer or
> > > > enclave signature.
> > > >
> > >
> > > I'm not sure, and also don't really think we need to commit to an
> > > answer right now.  I do think that the eventual solution should be
> > > more flexible than just whitelisting the signers.  In particular, it
> > > should be possible to make secure enclaves, open-source or otherwise,
> > > that are reproducibly buildable.  This more or less requires that the
> > > signing private key not be a secret, which means that no one would
> > > want to whitelist the signing key.  The enclave would be trusted, and
> > > would seal data, on the basis of its MRENCLAVE, and the policy, if
> > > any, would want to whitelist the MRENCLAVE or perhaps the whole
> > > SIGSTRUCT.
> > >
> > > But my overall point is that it should be possible to have a conherent
> > > policy that allows any enclave whatsoever to run but that still
> > > respects EXECMEM and such.
> >
> > So could kernel embed a fixed signing key that would be made available
> > through sysfs for signing? Already have one for my selftest.
> >
> 
> Do you mean a public and private key?  I was imagining that someone
> would just create a key pair and publish it for the case of SGX
> programs that don't depend on MRSIGNER.  There doesn't have to be just
> one.
> 
> But I may be misunderstanding you.

Aa, OK, got you. I actually misunderstood you.

/Jarkko

^ permalink raw reply

* Re: [PATCH v2 bpf-next 1/4] bpf: unprivileged BPF access via /dev/bpf
From: Andy Lutomirski @ 2019-08-07 13:52 UTC (permalink / raw)
  To: Lorenz Bauer
  Cc: Andy Lutomirski, Alexei Starovoitov, Song Liu, Kees Cook,
	Networking, bpf, Alexei Starovoitov, Daniel Borkmann, Kernel Team,
	Jann Horn, Greg KH, Linux API, LSM List
In-Reply-To: <CACAyw9_fVZFW_x4uyTAiRfeH6oq1KHv0uB2wO84u5JZyD+Unaw@mail.gmail.com>


> On Aug 7, 2019, at 2:03 AM, Lorenz Bauer <lmb@cloudflare.com> wrote:
> 
>> On Wed, 7 Aug 2019 at 06:24, Andy Lutomirski <luto@kernel.org> wrote:
>> a) Those that, by design, control privileged operations.  This
>> includes most attach calls, but it also includes allow_ptr_leaks,
>> bpf_probe_read(), and quite a few other things.  It also includes all
>> of the by_id calls, I think, unless some clever modification to the
>> way they worked would isolate different users' objects.  I think that
>> persistent objects can do pretty much everything that by_id users
>> would need, so this isn't a big deal.
> 
> Slightly OT, since this is an implementation question: GET_MAP_FD_BY_ID
> is useful to iterate a nested map. This isn't covered by rights to
> persistent objects,
> so it would need some thought.
> 
> 

A call to get an fd to a map referenced by a map to which you already have an fd seems reasonable to me. The new fd would inherit the old fd’s access mode.

^ permalink raw reply

* Re: [PATCH v2 bpf-next 1/4] bpf: unprivileged BPF access via /dev/bpf
From: Lorenz Bauer @ 2019-08-07  9:03 UTC (permalink / raw)
  To: Andy Lutomirski
  Cc: Alexei Starovoitov, Song Liu, Kees Cook, Networking, bpf,
	Alexei Starovoitov, Daniel Borkmann, Kernel Team, Jann Horn,
	Greg KH, Linux API, LSM List
In-Reply-To: <CALCETrXEHL3+NAY6P6vUj7Pvd9ZpZsYC6VCLXOaNxb90a_POGw@mail.gmail.com>

On Wed, 7 Aug 2019 at 06:24, Andy Lutomirski <luto@kernel.org> wrote:
> a) Those that, by design, control privileged operations.  This
> includes most attach calls, but it also includes allow_ptr_leaks,
> bpf_probe_read(), and quite a few other things.  It also includes all
> of the by_id calls, I think, unless some clever modification to the
> way they worked would isolate different users' objects.  I think that
> persistent objects can do pretty much everything that by_id users
> would need, so this isn't a big deal.

Slightly OT, since this is an implementation question: GET_MAP_FD_BY_ID
is useful to iterate a nested map. This isn't covered by rights to
persistent objects,
so it would need some thought.

-- 
Lorenz Bauer  |  Systems Engineer
6th Floor, County Hall/The Riverside Building, SE1 7PB, UK

www.cloudflare.com

^ permalink raw reply

* Re: [PATCH v2 bpf-next 1/4] bpf: unprivileged BPF access via /dev/bpf
From: Andy Lutomirski @ 2019-08-07  5:24 UTC (permalink / raw)
  To: Alexei Starovoitov
  Cc: Andy Lutomirski, Song Liu, Kees Cook, Networking, bpf,
	Alexei Starovoitov, Daniel Borkmann, Kernel Team, Lorenz Bauer,
	Jann Horn, Greg KH, Linux API, LSM List
In-Reply-To: <20190806011134.p5baub5l3t5fkmou@ast-mbp>

On Mon, Aug 5, 2019 at 6:11 PM Alexei Starovoitov
<alexei.starovoitov@gmail.com> wrote:
>
> On Mon, Aug 05, 2019 at 02:25:35PM -0700, Andy Lutomirski wrote:
> > It tries to make the kernel respect the access modes for fds.  Without
> > this patch, there seem to be some holes: nothing looked at program fds
> > and, unless I missed something, you could take a readonly fd for a
> > program, pin the program, and reopen it RW.
>
> I think it's by design. iirc Daniel had a use case for something like this.

That seems odd.  Daniel, can you elaborate?

> Hence unprivileged bpf is actually something that can be deprecated.

I hope not.  There are a couple setsockopt uses right now, and and
seccomp will surely want it someday.  And the bpf-inside-container use
case really is unprivileged bpf -- containers are, in many (most?)
cases, explicitly not trusted by the host.  But regardless, see below.

> > The ability to obtain an fd to a cgroup does *not* imply any right to
> > modify that cgroup.  The ability to write to a cgroup directory
> > already means something else -- it's the ability to create cgroups
> > under the group in question.  I'm suggesting that a new API be added
> > that allows attaching a bpf program to a cgroup without capabilities
> > and that instead requires write access to a new file in the cgroup
> > directory.  (It could be a single file for all bpf types or one file
> > per type.  I prefer the latter -- it gives the admin finer-grained
> > control.)
>
> This is something to discuss. I don't mind something like this,
> but in general bpf is not for untrusted users.
> Hence I don't want to overdesign.

I think the code would end up being extremely simple.  It would be an
ABI change, but I think that it could easily be arranged so that new
and old libbpf would be fully functional on new and old kernels except
that only new libbpf with a new kernel would be able to attach cgroup
programs without privilege.  I see no reason to remove the current
cgroup attach API.

> See https://github.com/systemd/systemd/blob/01234e1fe777602265ffd25ab6e73823c62b0efe/src/core/bpf-firewall.c#L671-L674
> bpf based IP sandboxing doesn't work in 'systemd --user'.
> That is just one of the problems that people complained about.

This isn't privilege *dropping* -- this is not having privilege in the
first place.  Giving systemd --user unrestricted use of bpf() is
tantamount to making the user root.  But again, see below.

>
> Inside containers and inside nested containers we need to start processes
> that will use bpf. All of the processes are trusted.

Trusted by whom?  In a non-nested container, the container manager
*might* be trusted by the outside world.  In a *nested* container,
unless the inner container management is controlled from outside the
outer container, it's not trusted.  I don't know much about how
Facebook's containers work, but the LXC/LXD/Podman world is moving
very strongly toward user namespaces and maximally-untrusted
containers, and I think bpf() should work in that context.

> To solve your concern of bypassing all capable checks...
> How about we do /dev/bpf/full_verifier first?
> It will replace capable() checks in the verifier only.

I'm not convinced that "in the verifier" is the right distinction.
Telling administrators that some setting lets certain users bypass
bpf() verifier checks doesn't have a clear enough meaning.  I propose,
instead, that the current capable() checks be divided into three
categories:

a) Those that, by design, control privileged operations.  This
includes most attach calls, but it also includes allow_ptr_leaks,
bpf_probe_read(), and quite a few other things.  It also includes all
of the by_id calls, I think, unless some clever modification to the
way they worked would isolate different users' objects.  I think that
persistent objects can do pretty much everything that by_id users
would need, so this isn't a big deal.

b) Those that protect code that is considered to be at higher risk of
exposing security bugs.  In other words, these are things that would
have no need for privilege if we could prove that the implementation
was perfect.  This includes bpf2bpf, LPM, etc.

c) Those that serve to prevent excessive resource usage.  This
includes the bounded loop code (I think -- this might also be category
(b)) and several explicit checks for program size.

I suppose that the speculative execution mitigation stuff could be
split out from (b) into its own category.

Based on this, how about a different division: /dev/bpf_dangerous for
(b) and /dev/bpf_resources for (c)?  And (a) is dealt with by
gradually reducing the privilege needed for the important operations.
/dev/bpf_dangerous isn't ideal in the long run though, since a lot of
the operations in that category will probably become less dangerous as
the code is better vetted, and people granting "dangerous" permission
might want to restrict it to only the specific parts that they need.
/dev/bpf_lpm, /dev/bpf2bpf, etc could work better.

This type of thing actually fits quite nicely into an idea I've been
thinking about for a while called "implicit rights". In very brief
summary, there would be objects called /dev/rights/xyz, where xyz is
the same of a "right".  If there is a readable object of the right
type at the literal path "/dev/rights/xyz", then you have right xyz.
There's a bit more flexibility on top of this.  BPF could use
/dev/rights/bpf/maptypes/lpm and
/dev/rights/bpf/verifier/bounded_loops, for example.  Other non-BPF
use cases include a biggie:
/dev/rights/namespace/create_unprivileged_userns.
/dev/rights/bind_port/80 would be nice, too.

I may have a bit of time over the next few days to actually prototype
this.  Would you be interested in using this for BPF?

^ permalink raw reply

* Re: [PATCH 1/2] KEYS: Replace uid/gid/perm permissions checking with an ACL
From: Eric Biggers @ 2019-08-07  2:58 UTC (permalink / raw)
  To: David Howells, keyrings, linux-security-module, linux-fsdevel,
	linux-kernel
In-Reply-To: <20190731011614.GA687@sol.localdomain>

On Tue, Jul 30, 2019 at 06:16:14PM -0700, Eric Biggers wrote:
> On Mon, Jul 29, 2019 at 08:49:56PM -0700, Eric Biggers wrote:
> > Hi David,
> > 
> > On Tue, Jul 09, 2019 at 06:16:01PM -0700, Eric Biggers wrote:
> > > On Thu, May 23, 2019 at 04:58:27PM +0100, David Howells wrote:
> > > > Replace the uid/gid/perm permissions checking on a key with an ACL to allow
> > > > the SETATTR and SEARCH permissions to be split.  This will also allow a
> > > > greater range of subjects to represented.
> > > > 
> > > 
> > > This patch broke 'keyctl new_session', and hence broke all the fscrypt tests:
> > > 
> > > $ keyctl new_session
> > > keyctl_session_to_parent: Permission denied
> > > 
> > > Output of 'keyctl show' is
> > > 
> > > $ keyctl show
> > > Session Keyring
> > >  605894913 --alswrv      0     0  keyring: _ses
> > >  189223103 ----s-rv      0     0   \_ user: invocation_id
> > > 
> > > - Eric
> > 
> > This bug is still present in next-20190729.
> > 
> > - Eric
> 
> This fixes it:
> 
> diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
> index aa3bfcadbc660..519c94f1cc3c2 100644
> --- a/security/keys/process_keys.c
> +++ b/security/keys/process_keys.c
> @@ -58,7 +58,7 @@ static struct key_acl session_keyring_acl = {
>  	.possessor_viewable = true,
>  	.nr_ace	= 2,
>  	.aces = {
> -		KEY_POSSESSOR_ACE(KEY_ACE__PERMS & ~KEY_ACE_JOIN),
> +		KEY_POSSESSOR_ACE(KEY_ACE__PERMS),
>  		KEY_OWNER_ACE(KEY_ACE_VIEW | KEY_ACE_READ),
>  	}
>  };
> 
> 
> The old permissions were KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ, so
> I'm not sure why JOIN permission was removed?
> 
> - Eric

Ping.  This is still broken in linux-next.

- Eric

^ permalink raw reply

* [PATCH v3 37/41] security/tomoyo: convert put_page() to put_user_page*()
From: john.hubbard @ 2019-08-07  1:33 UTC (permalink / raw)
  To: Andrew Morton
  Cc: Christoph Hellwig, Dan Williams, Dave Chinner, Dave Hansen,
	Ira Weiny, Jan Kara, Jason Gunthorpe, Jérôme Glisse,
	LKML, amd-gfx, ceph-devel, devel, devel, dri-devel, intel-gfx,
	kvm, linux-arm-kernel, linux-block, linux-crypto, linux-fbdev,
	linux-fsdevel, linux-media, linux-mm, linux-nfs, linux-rdma,
	linux-rpi-kernel, linux-xfs, netdev, rds-devel, sparclinux, x86,
	xen-devel, John Hubbard, Tetsuo Handa, Kentaro Takeda,
	linux-security-module
In-Reply-To: <20190807013340.9706-1-jhubbard@nvidia.com>

From: John Hubbard <jhubbard@nvidia.com>

For pages that were retained via get_user_pages*(), release those pages
via the new put_user_page*() routines, instead of via put_page() or
release_pages().

This is part a tree-wide conversion, as described in commit fc1d8e7cca2d
("mm: introduce put_user_page*(), placeholder versions").

Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>

Cc: Kentaro Takeda <takedakn@nttdata.co.jp>
Cc: linux-security-module@vger.kernel.org
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---
 security/tomoyo/domain.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/security/tomoyo/domain.c b/security/tomoyo/domain.c
index 8526a0a74023..6887beecfb6e 100644
--- a/security/tomoyo/domain.c
+++ b/security/tomoyo/domain.c
@@ -931,7 +931,7 @@ bool tomoyo_dump_page(struct linux_binprm *bprm, unsigned long pos,
 	}
 	/* Same with put_arg_page(page) in fs/exec.c */
 #ifdef CONFIG_MMU
-	put_page(page);
+	put_user_page(page);
 #endif
 	return true;
 }
-- 
2.22.0


^ permalink raw reply related

* Re: [RFC PATCH v1 1/5] fs: Add support for an O_MAYEXEC flag on sys_open()
From: Mickaël Salaün @ 2019-08-06 16:40 UTC (permalink / raw)
  To: Andy Lutomirski, Jan Kara, Song Liu, Alexei Starovoitov,
	Daniel Borkmann
  Cc: LKML, Al Viro, James Morris, Jonathan Corbet, Kees Cook,
	Matthew Garrett, Michael Kerrisk, Mickaël Salaün,
	Mimi Zohar, Philippe Trébuchet, Shuah Khan,
	Thibaut Sautereau, Vincent Strubel, Yves-Alexis Perez,
	Kernel Hardening, Linux API, LSM List, Linux FS Devel,
	Steve Grubb, Matthew Bobrowski, Aleksa Sarai, Sean Christopherson
In-Reply-To: <CALCETrVeZ0eufFXwfhtaG_j+AdvbzEWE0M3wjXMWVEO7pj+xkw@mail.gmail.com>


On 05/08/2019 01:55, Andy Lutomirski wrote:
> On Wed, Dec 12, 2018 at 6:43 AM Jan Kara <jack@suse.cz> wrote:
>>
>> On Wed 12-12-18 09:17:08, Mickaël Salaün wrote:
>>> When the O_MAYEXEC flag is passed, sys_open() may be subject to
>>> additional restrictions depending on a security policy implemented by an
>>> LSM through the inode_permission hook.
>>>
>>> The underlying idea is to be able to restrict scripts interpretation
>>> according to a policy defined by the system administrator.  For this to
>>> be possible, script interpreters must use the O_MAYEXEC flag
>>> appropriately.  To be fully effective, these interpreters also need to
>>> handle the other ways to execute code (for which the kernel can't help):
>>> command line parameters (e.g., option -e for Perl), module loading
>>> (e.g., option -m for Python), stdin, file sourcing, environment
>>> variables, configuration files...  According to the threat model, it may
>>> be acceptable to allow some script interpreters (e.g. Bash) to interpret
>>> commands from stdin, may it be a TTY or a pipe, because it may not be
>>> enough to (directly) perform syscalls.
>>>
>>> A simple security policy implementation is available in a following
>>> patch for Yama.
>>>
>>> This is an updated subset of the patch initially written by Vincent
>>> Strubel for CLIP OS:
>>> https://github.com/clipos-archive/src_platform_clip-patches/blob/f5cb330d6b684752e403b4e41b39f7004d88e561/1901_open_mayexec.patch
>>> This patch has been used for more than 10 years with customized script
>>> interpreters.  Some examples can be found here:
>>> https://github.com/clipos-archive/clipos4_portage-overlay/search?q=O_MAYEXEC
>>>
>>> Signed-off-by: Mickaël Salaün <mic@digikod.net>
>>> Signed-off-by: Thibaut Sautereau <thibaut.sautereau@ssi.gouv.fr>
>>> Signed-off-by: Vincent Strubel <vincent.strubel@ssi.gouv.fr>
>>> Reviewed-by: Philippe Trébuchet <philippe.trebuchet@ssi.gouv.fr>
>>> Cc: Al Viro <viro@zeniv.linux.org.uk>
>>> Cc: Kees Cook <keescook@chromium.org>
>>> Cc: Mickaël Salaün <mickael.salaun@ssi.gouv.fr>
>>
>> ...
>>
>>> diff --git a/fs/open.c b/fs/open.c
>>> index 0285ce7dbd51..75479b79a58f 100644
>>> --- a/fs/open.c
>>> +++ b/fs/open.c
>>> @@ -974,6 +974,10 @@ static inline int build_open_flags(int flags, umode_t mode, struct open_flags *o
>>>       if (flags & O_APPEND)
>>>               acc_mode |= MAY_APPEND;
>>>
>>> +     /* Check execution permissions on open. */
>>> +     if (flags & O_MAYEXEC)
>>> +             acc_mode |= MAY_OPENEXEC;
>>> +
>>>       op->acc_mode = acc_mode;
>>>
>>>       op->intent = flags & O_PATH ? 0 : LOOKUP_OPEN;
>>
>> I don't feel experienced enough in security to tell whether we want this
>> functionality or not. But if we do this, shouldn't we also set FMODE_EXEC
>> on the resulting struct file? That way also security_file_open() can be
>> used to arbitrate such executable opens and in particular
>> fanotify permission event FAN_OPEN_EXEC will get properly generated which I
>> guess is desirable (support for it is sitting in my tree waiting for the
>> merge window) - adding some audit people involved in FAN_OPEN_EXEC to
>> CC. Just an idea...
>>
> 
> I would really like to land this patch.  I'm fiddling with making
> bpffs handle permissions intelligently, and the lack of a way to say
> "hey, I want to open this bpf program so that I can run it" is
> annoying.

Are you OK with this series? What about Aleksa's work on openat2(), and
Sean's work on SGX/noexec? Is it time to send a new patch series (with a
dedicated LSM instead of Yama)?

^ permalink raw reply

* Re: [GIT PULL] SafeSetID MAINTAINERS file update for v5.3
From: Micah Morton @ 2019-08-06 16:32 UTC (permalink / raw)
  To: Konstantin Ryabitsev
  Cc: Linus Torvalds, linux-security-module, Linux Kernel Mailing List
In-Reply-To: <20190805192727.GA15470@chatter.i7.local>

On Mon, Aug 5, 2019 at 12:27 PM Konstantin Ryabitsev
<konstantin@linuxfoundation.org> wrote:
>
> On Mon, Aug 05, 2019 at 12:17:49PM -0700, Linus Torvalds wrote:
> >> However, I suspect that getting message-ids for all your pull
> >> requests
> >> would significantly complicate your workflow.
> >
> >Yeah, that would be a noticeable annoyance. If I were to process pull
> >requests the way I used to process emailed patches (ie "git am -s" on
> >a mailbox) that would be a natural thing to perhaps do, but it's not
> >at all how it ends up working. Having to save the pull request email
> >to then process it with some script would turn it into a chore.
> >
> >I think the pr-tracker-bot clearly catches most cases as it is, and
> >it's only the occasional "somebody did something odd" that then misses
> >an automated response. Not a huge deal. For me it was actually more
> >the "I didn't understand why the response didn't happen", not so much
> >"I really want to always see responses".
>
> Ok, let me add a fix for Re: at the start -- this won't make things
> significantly more expensive, but will catch this particular corner
> case.
>
> Best regards,
> -K

Linus, thanks for the tips earlier about gitk. I'll use that in the future.

Unfortunately I didn't have the mental model quite right of what
happens during the pull request. I was thinking along the lines of my
commits being cherry picked onto your tree, rather than how it
actually happens with git merge where my tree's commit history needs
to match yours perfectly.

^ permalink raw reply


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