1 files changed, 29 insertions, 7 deletions

diff --git a/security/selinux/avc.c b/security/selinux/avc.c
index 9da6420e2056..1d027e29ce8d 100644
--- a/security/selinux/avc.c
+++ b/security/selinux/avc.c
@@ -471,6 +471,7 @@ static void avc_audit_post_callback(struct audit_buffer *ab, void *a)
  * @avd: access vector decisions
  * @result: result from avc_has_perm_noaudit
  * @a:  auxiliary audit data
+ * @flags: VFS walk flags
  *
  * Audit the granting or denial of permissions in accordance
  * with the policy.  This function is typically called by
@@ -481,9 +482,10 @@ static void avc_audit_post_callback(struct audit_buffer *ab, void *a)
  * be performed under a lock, to allow the lock to be released
  * before calling the auditing code.
  */
-void avc_audit(u32 ssid, u32 tsid,
+int avc_audit(u32 ssid, u32 tsid,
                u16 tclass, u32 requested,
-               struct av_decision *avd, int result, struct common_audit_data *a)
+               struct av_decision *avd, int result, struct common_audit_data *a,
+               unsigned flags)
 {
         struct common_audit_data stack_data;
         u32 denied, audited;
@@ -515,11 +517,24 @@ void avc_audit(u32 ssid, u32 tsid,
         else
                 audited = requested & avd->auditallow;
         if (!audited)
-                return;
+                return 0;
+
         if (!a) {
                 a = &stack_data;
                 COMMON_AUDIT_DATA_INIT(a, NONE);
         }
+
+        /*
+         * When in a RCU walk do the audit on the RCU retry.  This is because
+         * the collection of the dname in an inode audit message is not RCU
+         * safe.  Note this may drop some audits when the situation changes
+         * during retry. However this is logically just as if the operation
+         * happened a little later.
+         */
+        if ((a->type == LSM_AUDIT_DATA_FS) &&
+            (flags & IPERM_FLAG_RCU))
+                return -ECHILD;
+
         a->selinux_audit_data.tclass = tclass;
         a->selinux_audit_data.requested = requested;
         a->selinux_audit_data.ssid = ssid;
@@ -529,6 +544,7 @@ void avc_audit(u32 ssid, u32 tsid,
         a->lsm_pre_audit = avc_audit_pre_callback;
         a->lsm_post_audit = avc_audit_post_callback;
         common_lsm_audit(a);
+        return 0;
 }
 
 /**
@@ -793,6 +809,7 @@ int avc_has_perm_noaudit(u32 ssid, u32 tsid,
  * @tclass: target security class
  * @requested: requested permissions, interpreted based on @tclass
  * @auditdata: auxiliary audit data
+ * @flags: VFS walk flags
  *
  * Check the AVC to determine whether the @requested permissions are granted
  * for the SID pair (@ssid, @tsid), interpreting the permissions
@@ -802,14 +819,19 @@ int avc_has_perm_noaudit(u32 ssid, u32 tsid,
  * permissions are granted, -%EACCES if any permissions are denied, or
  * another -errno upon other errors.
  */
-int avc_has_perm(u32 ssid, u32 tsid, u16 tclass,
-                 u32 requested, struct common_audit_data *auditdata)
+int avc_has_perm_flags(u32 ssid, u32 tsid, u16 tclass,
+                       u32 requested, struct common_audit_data *auditdata,
+                       unsigned flags)
 {
         struct av_decision avd;
-        int rc;
+        int rc, rc2;
 
         rc = avc_has_perm_noaudit(ssid, tsid, tclass, requested, 0, &avd);
-        avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata);
+
+        rc2 = avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata,
+                        flags);
+        if (rc2)
+                return rc2;
         return rc;
 }