Patch "af_unix: take receive queue lock while appending new skb" has been added to the 4.3-stable tree

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

af_unix: take receive queue lock while appending new skb

to the 4.3-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:
af_unix-take-receive-queue-lock-while-appending-new-skb.patch
and it can be found in the queue-4.3 subdirectory.

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

From: Hannes Frederic Sowa <[email protected]>
Date: Tue, 17 Nov 2015 15:10:59 +0100
Subject: af_unix: take receive queue lock while appending new skb

From: Hannes Frederic Sowa <[email protected]>

[ Upstream commit a3a116e04cc6a94d595ead4e956ab1bc1d2f4746 ]

While possibly in future we don't necessarily need to use sk_buff_head.lock this is a rather larger change, as it affects the af_unix fd garbage collector, diag and socket cleanups. This is too much for a stable patch.

For the time being grab sk_buff_head.lock without disabling bh and irqs, so don't use locked skb_queue_tail.

---
 net/unix/af_unix.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

@@ -1812,8 +1812,11 @@ alloc_skb:
 	skb->truesize += size;
 	atomic_add(size, &sk->sk_wmem_alloc);
 
-	if (newskb)
+	if (newskb) {
+		spin_lock(&other->sk_receive_queue.lock);
 		__skb_queue_tail(&other->sk_receive_queue, newskb);
+		spin_unlock(&other->sk_receive_queue.lock);
+	}
 
 	unix_state_unlock(other);
 	mutex_unlock(&unix_sk(other)->readlock);

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

queue-4.3/ipv6-add-complete-rcu-protection-around-np-opt.patch queue-4.3/ipv6-check-rt-dst.from-for-the-dst_nocache-route.patch queue-4.3/af-unix-passcred-support-for-sendpage.patch queue-4.3/af_unix-don-t-append-consumed-skbs-to-sk_receive_queue.patch queue-4.3/ipv6-avoid-creating-rtf_cache-from-a-rt-that-is-not-managed-by-fib6-tree.patch queue-4.3/net-scm-fix-pax-detected-msg_controllen-overflow-in-scm_detach_fds.patch queue-4.3/ipv6-check-expire-on-dst_nocache-route.patch queue-4.3/af-unix-fix-use-after-free-with-concurrent-readers-while-splicing.patch queue-4.3/ip_tunnel-disable-preemption-when-updating-per-cpu-tstats.patch queue-4.3/af_unix-take-receive-queue-lock-while-appending-new-skb.patch