1 files changed, 54 insertions, 65 deletions

diff --git a/security/selinux/avc.c b/security/selinux/avc.c
index d18cb32a242a..9a43af0ebd7d 100644
--- a/security/selinux/avc.c
+++ b/security/selinux/avc.c
@@ -31,6 +31,9 @@
 #include "avc_ss.h"
 #include "classmap.h"
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/avc.h>
+
 #define AVC_CACHE_SLOTS			512
 #define AVC_DEF_CACHE_THRESHOLD		512
 #define AVC_CACHE_RECLAIM		16
@@ -115,11 +118,11 @@ void avc_set_cache_threshold(struct selinux_avc *avc,
 	avc->avc_cache_threshold = cache_threshold;
 }
 
-static struct avc_callback_node *avc_callbacks;
-static struct kmem_cache *avc_node_cachep;
-static struct kmem_cache *avc_xperms_data_cachep;
-static struct kmem_cache *avc_xperms_decision_cachep;
-static struct kmem_cache *avc_xperms_cachep;
+static struct avc_callback_node *avc_callbacks __ro_after_init;
+static struct kmem_cache *avc_node_cachep __ro_after_init;
+static struct kmem_cache *avc_xperms_data_cachep __ro_after_init;
+static struct kmem_cache *avc_xperms_decision_cachep __ro_after_init;
+static struct kmem_cache *avc_xperms_cachep __ro_after_init;
 
 static inline int avc_hash(u32 ssid, u32 tsid, u16 tclass)
 {
@@ -294,26 +297,27 @@ static struct avc_xperms_decision_node
 	struct avc_xperms_decision_node *xpd_node;
 	struct extended_perms_decision *xpd;
 
-	xpd_node = kmem_cache_zalloc(avc_xperms_decision_cachep, GFP_NOWAIT);
+	xpd_node = kmem_cache_zalloc(avc_xperms_decision_cachep,
+				     GFP_NOWAIT | __GFP_NOWARN);
 	if (!xpd_node)
 		return NULL;
 
 	xpd = &xpd_node->xpd;
 	if (which & XPERMS_ALLOWED) {
 		xpd->allowed = kmem_cache_zalloc(avc_xperms_data_cachep,
-						GFP_NOWAIT);
+						GFP_NOWAIT | __GFP_NOWARN);
 		if (!xpd->allowed)
 			goto error;
 	}
 	if (which & XPERMS_AUDITALLOW) {
 		xpd->auditallow = kmem_cache_zalloc(avc_xperms_data_cachep,
-						GFP_NOWAIT);
+						GFP_NOWAIT | __GFP_NOWARN);
 		if (!xpd->auditallow)
 			goto error;
 	}
 	if (which & XPERMS_DONTAUDIT) {
 		xpd->dontaudit = kmem_cache_zalloc(avc_xperms_data_cachep,
-						GFP_NOWAIT);
+						GFP_NOWAIT | __GFP_NOWARN);
 		if (!xpd->dontaudit)
 			goto error;
 	}
@@ -341,7 +345,7 @@ static struct avc_xperms_node *avc_xperms_alloc(void)
 {
 	struct avc_xperms_node *xp_node;
 
-	xp_node = kmem_cache_zalloc(avc_xperms_cachep, GFP_NOWAIT);
+	xp_node = kmem_cache_zalloc(avc_xperms_cachep, GFP_NOWAIT | __GFP_NOWARN);
 	if (!xp_node)
 		return xp_node;
 	INIT_LIST_HEAD(&xp_node->xpd_head);
@@ -497,7 +501,7 @@ static struct avc_node *avc_alloc_node(struct selinux_avc *avc)
 {
 	struct avc_node *node;
 
-	node = kmem_cache_zalloc(avc_node_cachep, GFP_NOWAIT);
+	node = kmem_cache_zalloc(avc_node_cachep, GFP_NOWAIT | __GFP_NOWARN);
 	if (!node)
 		goto out;
 
@@ -543,6 +547,7 @@ static inline struct avc_node *avc_search_node(struct selinux_avc *avc,
 
 /**
  * avc_lookup - Look up an AVC entry.
+ * @avc: the access vector cache
  * @ssid: source security identifier
  * @tsid: target security identifier
  * @tclass: target security class
@@ -593,6 +598,7 @@ static int avc_latest_notif_update(struct selinux_avc *avc,
 
 /**
  * avc_insert - Insert an AVC entry.
+ * @avc: the access vector cache
  * @ssid: source security identifier
  * @tsid: target security identifier
  * @tclass: target security class
@@ -662,7 +668,7 @@ static void avc_audit_pre_callback(struct audit_buffer *ab, void *a)
 	struct common_audit_data *ad = a;
 	struct selinux_audit_data *sad = ad->selinux_audit_data;
 	u32 av = sad->audited;
-	const char **perms;
+	const char *const *perms;
 	int i, perm;
 
 	audit_log_format(ab, "avc:  %s ", sad->denied ? "denied" : "granted");
@@ -702,33 +708,37 @@ static void avc_audit_post_callback(struct audit_buffer *ab, void *a)
 {
 	struct common_audit_data *ad = a;
 	struct selinux_audit_data *sad = ad->selinux_audit_data;
-	char *scontext;
+	char *scontext = NULL;
+	char *tcontext = NULL;
+	const char *tclass = NULL;
 	u32 scontext_len;
+	u32 tcontext_len;
 	int rc;
 
 	rc = security_sid_to_context(sad->state, sad->ssid, &scontext,
 				     &scontext_len);
 	if (rc)
 		audit_log_format(ab, " ssid=%d", sad->ssid);
-	else {
+	else
 		audit_log_format(ab, " scontext=%s", scontext);
-		kfree(scontext);
-	}
 
-	rc = security_sid_to_context(sad->state, sad->tsid, &scontext,
-				     &scontext_len);
+	rc = security_sid_to_context(sad->state, sad->tsid, &tcontext,
+				     &tcontext_len);
 	if (rc)
 		audit_log_format(ab, " tsid=%d", sad->tsid);
-	else {
-		audit_log_format(ab, " tcontext=%s", scontext);
-		kfree(scontext);
-	}
+	else
+		audit_log_format(ab, " tcontext=%s", tcontext);
 
-	audit_log_format(ab, " tclass=%s", secclass_map[sad->tclass-1].name);
+	tclass = secclass_map[sad->tclass-1].name;
+	audit_log_format(ab, " tclass=%s", tclass);
 
 	if (sad->denied)
 		audit_log_format(ab, " permissive=%u", sad->result ? 0 : 1);
 
+	trace_selinux_audited(sad, scontext, tcontext, tclass);
+	kfree(tcontext);
+	kfree(scontext);
+
 	/* in case of invalid context report also the actual context string */
 	rc = security_sid_to_context_inval(sad->state, sad->ssid, &scontext,
 					   &scontext_len);
@@ -751,7 +761,11 @@ static void avc_audit_post_callback(struct audit_buffer *ab, void *a)
 	}
 }
 
-/* This is the slow part of avc audit with big stack footprint */
+/*
+ * This is the slow part of avc audit with big stack footprint.
+ * Note that it is non-blocking and can be called from under
+ * rcu_read_lock().
+ */
 noinline int slow_avc_audit(struct selinux_state *state,
 			    u32 ssid, u32 tsid, u16 tclass,
 			    u32 requested, u32 audited, u32 denied, int result,
@@ -812,13 +826,18 @@ out:
 }
 
 /**
- * avc_update_node Update an AVC entry
+ * avc_update_node - Update an AVC entry
+ * @avc: the access vector cache
  * @event : Updating event
  * @perms : Permission mask bits
- * @ssid,@tsid,@tclass : identifier of an AVC entry
+ * @driver: xperm driver information
+ * @xperm: xperm permissions
+ * @ssid: AVC entry source sid
+ * @tsid: AVC entry target sid
+ * @tclass : AVC entry target object class
  * @seqno : sequence number when decision was made
  * @xpd: extended_perms_decision to be added to the node
- * @flags: the AVC_* flags, e.g. AVC_NONBLOCKING, AVC_EXTENDED_PERMS, or 0.
+ * @flags: the AVC_* flags, e.g. AVC_EXTENDED_PERMS, or 0.
  *
  * if a valid AVC entry doesn't exist,this function returns -ENOENT.
  * if kmalloc() called internal returns NULL, this function returns -ENOMEM.
@@ -837,21 +856,6 @@ static int avc_update_node(struct selinux_avc *avc,
 	struct hlist_head *head;
 	spinlock_t *lock;
 
-	/*
-	 * If we are in a non-blocking code path, e.g. VFS RCU walk,
-	 * then we must not add permissions to a cache entry
-	 * because we will not audit the denial.  Otherwise,
-	 * during the subsequent blocking retry (e.g. VFS ref walk), we
-	 * will find the permissions already granted in the cache entry
-	 * and won't audit anything at all, leading to silent denials in
-	 * permissive mode that only appear when in enforcing mode.
-	 *
-	 * See the corresponding handling of MAY_NOT_BLOCK in avc_audit()
-	 * and selinux_inode_permission().
-	 */
-	if (flags & AVC_NONBLOCKING)
-		return 0;
-
 	node = avc_alloc_node(avc);
 	if (!node) {
 		rc = -ENOMEM;
@@ -931,6 +935,7 @@ out:
 
 /**
  * avc_flush - Flush the cache
+ * @avc: the access vector cache
  */
 static void avc_flush(struct selinux_avc *avc)
 {
@@ -959,6 +964,7 @@ static void avc_flush(struct selinux_avc *avc)
 
 /**
  * avc_ss_reset - Flush the cache and revalidate migrated permissions.
+ * @avc: the access vector cache
  * @seqno: policy sequence number
  */
 int avc_ss_reset(struct selinux_avc *avc, u32 seqno)
@@ -1053,7 +1059,7 @@ int avc_has_extended_perms(struct selinux_state *state,
 
 	node = avc_lookup(state->avc, ssid, tsid, tclass);
 	if (unlikely(!node)) {
-		node = avc_compute_av(state, ssid, tsid, tclass, &avd, xp_node);
+		avc_compute_av(state, ssid, tsid, tclass, &avd, xp_node);
 	} else {
 		memcpy(&avd, &node->ae.avd, sizeof(avd));
 		xp_node = node->ae.xp_node;
@@ -1108,11 +1114,12 @@ decision:
 
 /**
  * avc_has_perm_noaudit - Check permissions but perform no auditing.
+ * @state: SELinux state
  * @ssid: source security identifier
  * @tsid: target security identifier
  * @tclass: target security class
  * @requested: requested permissions, interpreted based on @tclass
- * @flags:  AVC_STRICT, AVC_NONBLOCKING, or 0
+ * @flags:  AVC_STRICT or 0
  * @avd: access vector decisions
  *
  * Check the AVC to determine whether the @requested permissions are granted
@@ -1144,7 +1151,7 @@ inline int avc_has_perm_noaudit(struct selinux_state *state,
 
 	node = avc_lookup(state->avc, ssid, tsid, tclass);
 	if (unlikely(!node))
-		node = avc_compute_av(state, ssid, tsid, tclass, avd, &xp_node);
+		avc_compute_av(state, ssid, tsid, tclass, avd, &xp_node);
 	else
 		memcpy(avd, &node->ae.avd, sizeof(*avd));
 
@@ -1159,6 +1166,7 @@ inline int avc_has_perm_noaudit(struct selinux_state *state,
 
 /**
  * avc_has_perm - Check permissions and perform any appropriate auditing.
+ * @state: SELinux state
  * @ssid: source security identifier
  * @tsid: target security identifier
  * @tclass: target security class
@@ -1183,26 +1191,7 @@ int avc_has_perm(struct selinux_state *state, u32 ssid, u32 tsid, u16 tclass,
 				  &avd);
 
 	rc2 = avc_audit(state, ssid, tsid, tclass, requested, &avd, rc,
-			auditdata, 0);
-	if (rc2)
-		return rc2;
-	return rc;
-}
-
-int avc_has_perm_flags(struct selinux_state *state,
-		       u32 ssid, u32 tsid, u16 tclass, u32 requested,
-		       struct common_audit_data *auditdata,
-		       int flags)
-{
-	struct av_decision avd;
-	int rc, rc2;
-
-	rc = avc_has_perm_noaudit(state, ssid, tsid, tclass, requested,
-				  (flags & MAY_NOT_BLOCK) ? AVC_NONBLOCKING : 0,
-				  &avd);
-
-	rc2 = avc_audit(state, ssid, tsid, tclass, requested, &avd, rc,
-			auditdata, flags);
+			auditdata);
 	if (rc2)
 		return rc2;
 	return rc;