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| author | Eric Dumazet <edumazet@google.com> | 2016-06-20 15:00:43 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-07-11 09:30:00 -0700 |
| commit | 16e0f188281a37de74bb3e0ed007a8a24c5901b3 (patch) | |
| tree | fd5f24fdbf98b36f85261b83d917878f1f7ba12c | |
| parent | 5438c1a50370c598cc536240b4e2c478a118d19b (diff) | |
| download | lwn-16e0f188281a37de74bb3e0ed007a8a24c5901b3.tar.gz lwn-16e0f188281a37de74bb3e0ed007a8a24c5901b3.zip | |
netem: fix a use after free
[ 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@google.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/sched/sch_netem.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c index 4befe97a9034..b7c29d5b6f04 100644 --- 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; } |