1 files changed, 15 insertions, 4 deletions

diff --git a/security/selinux/avc.c b/security/selinux/avc.c
index 1ed0f076aadc..b4b5da1c0a42 100644
--- a/security/selinux/avc.c
+++ b/security/selinux/avc.c
@@ -868,8 +868,19 @@ u32 avc_policy_seqno(void)
 
 void avc_disable(void)
 {
-        avc_flush();
-        synchronize_rcu();
-        if (avc_node_cachep)
-                kmem_cache_destroy(avc_node_cachep);
+        /*
+         * If you are looking at this because you have realized that we are
+         * not destroying the avc_node_cachep it might be easy to fix, but
+         * I don't know the memory barrier semantics well enough to know.  It's
+         * possible that some other task dereferenced security_ops when
+         * it still pointed to selinux operations.  If that is the case it's
+         * possible that it is about to use the avc and is about to need the
+         * avc_node_cachep.  I know I could wrap the security.c security_ops call
+         * in an rcu_lock, but seriously, it's not worth it.  Instead I just flush
+         * the cache and get that memory back.
+         */
+        if (avc_node_cachep) {
+                avc_flush();
+                /* kmem_cache_destroy(avc_node_cachep); */
+        }
 }