Patch "l2tp: protect tunnel->del_work by ref_count" has been added to the 3.14-stable tree

This is a note to let you know that I've just added the patch titled

    l2tp: protect tunnel->del_work by ref_count

to the 3.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
l2tp-protect-tunnel-del_work-by-ref_count.patch
and it can be found in the queue-3.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Alexander Couzens <[email protected]>
Date: Mon, 28 Sep 2015 11:32:42 +0200
Subject: l2tp: protect tunnel->del_work by ref_count

From: Alexander Couzens <[email protected]>

[ Upstream commit 06a15f51cf3618e32a73871ee6a547ef7fd902b5 ]

There is a small chance that tunnel_free() is called before tunnel->del_work scheduled resulting in a zero pointer dereference.

---
 net/l2tp/l2tp_core.c |   11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

@@ -1435,7 +1435,7 @@ static void l2tp_tunnel_del_work(struct
 	tunnel = container_of(work, struct l2tp_tunnel, del_work);
 	sk = l2tp_tunnel_sock_lookup(tunnel);
 	if (!sk)
-		return;
+		goto out;
 
 	sock = sk->sk_socket;
 

@@ -1456,6 +1456,8 @@ static void l2tp_tunnel_del_work(struct
 	}
 
 	l2tp_tunnel_sock_put(sk);
+out:
+	l2tp_tunnel_dec_refcount(tunnel);
 }
 
 /* Create a socket for the tunnel, if one isn't set up by

@@ -1785,8 +1787,13 @@ EXPORT_SYMBOL_GPL(l2tp_tunnel_create);
  */
 int l2tp_tunnel_delete(struct l2tp_tunnel *tunnel)
 {
+	l2tp_tunnel_inc_refcount(tunnel);
 	l2tp_tunnel_closeall(tunnel);
-	return (false == queue_work(l2tp_wq, &tunnel->del_work));
+	if (false == queue_work(l2tp_wq, &tunnel->del_work)) {
+		l2tp_tunnel_dec_refcount(tunnel);
+		return 1;
+	}
+	return 0;
 }
 EXPORT_SYMBOL_GPL(l2tp_tunnel_delete);
 

Patches currently in stable-queue which might be from [email protected] are

queue-3.14/l2tp-protect-tunnel-del_work-by-ref_count.patch