Patch "netem: fix a use after free" has been added to the 4.6-stable tree

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

netem: fix a use after free

to the 4.6-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:
netem-fix-a-use-after-free.patch
and it can be found in the queue-4.6 subdirectory.

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

From: Eric Dumazet <[email protected]>
Date: Mon, 20 Jun 2016 15:00:43 -0700
Subject: netem: fix a use after free

From: Eric Dumazet <[email protected]>

[ Upstream commit 21de12ee5568fd1aec47890c72967abf791ac80a ]

If the packet was dropped by lower qdisc, then we must not access it later.

Save qdisc_pkt_len(skb) in a temp variable.

---
 net/sched/sch_netem.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

@@ -650,14 +650,14 @@ deliver:
 #endif
 
 			if (q->qdisc) {
+				unsigned int pkt_len = qdisc_pkt_len(skb);
 				int err = qdisc_enqueue(skb, q->qdisc);
 
-				if (unlikely(err != NET_XMIT_SUCCESS)) {
-					if (net_xmit_drop_count(err)) {
-						qdisc_qstats_drop(sch);
-						qdisc_tree_reduce_backlog(sch, 1,
-									  qdisc_pkt_len(skb));
-					}
+				if (err != NET_XMIT_SUCCESS &&
+				    net_xmit_drop_count(err)) {
+					qdisc_qstats_drop(sch);
+					qdisc_tree_reduce_backlog(sch, 1,
+								  pkt_len);
 				}
 				goto tfifo_dequeue;
 			}

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

queue-4.6/netem-fix-a-use-after-free.patch queue-4.6/net_sched-fix-pfifo_head_drop-behavior-vs-backlog.patch