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 <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Wed Jul 6 16:50:56 PDT 2016
From: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Mon, 20 Jun 2016 15:00:43 -0700
Subject: netem: fix a use after free
From: Eric Dumazet <edumazet@xxxxxxxxxx>
[ 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.
Fixes: 2ccccf5fb43f ("net_sched: update hierarchical backlog too")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: WANG Cong <xiyou.wangcong@xxxxxxxxx>
Cc: Jamal Hadi Salim <jhs@xxxxxxxxxxxx>
Cc: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/sched/sch_netem.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -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 edumazet@xxxxxxxxxx are
queue-4.6/netem-fix-a-use-after-free.patch
queue-4.6/net_sched-fix-pfifo_head_drop-behavior-vs-backlog.patch
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