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Commit | Line | Data |
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bf1e68bf GKH |
1 | From foo@baz Wed Jul 6 16:50:56 PDT 2016 |
2 | From: Eric Dumazet <edumazet@google.com> | |
3 | Date: Mon, 20 Jun 2016 15:00:43 -0700 | |
4 | Subject: netem: fix a use after free | |
5 | ||
6 | From: Eric Dumazet <edumazet@google.com> | |
7 | ||
8 | [ Upstream commit 21de12ee5568fd1aec47890c72967abf791ac80a ] | |
9 | ||
10 | If the packet was dropped by lower qdisc, then we must not | |
11 | access it later. | |
12 | ||
13 | Save qdisc_pkt_len(skb) in a temp variable. | |
14 | ||
15 | Fixes: 2ccccf5fb43f ("net_sched: update hierarchical backlog too") | |
16 | Signed-off-by: Eric Dumazet <edumazet@google.com> | |
17 | Cc: WANG Cong <xiyou.wangcong@gmail.com> | |
18 | Cc: Jamal Hadi Salim <jhs@mojatatu.com> | |
19 | Cc: Stephen Hemminger <stephen@networkplumber.org> | |
20 | Signed-off-by: David S. Miller <davem@davemloft.net> | |
21 | Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
22 | --- | |
23 | net/sched/sch_netem.c | 12 ++++++------ | |
24 | 1 file changed, 6 insertions(+), 6 deletions(-) | |
25 | ||
26 | --- a/net/sched/sch_netem.c | |
27 | +++ b/net/sched/sch_netem.c | |
28 | @@ -650,14 +650,14 @@ deliver: | |
29 | #endif | |
30 | ||
31 | if (q->qdisc) { | |
32 | + unsigned int pkt_len = qdisc_pkt_len(skb); | |
33 | int err = qdisc_enqueue(skb, q->qdisc); | |
34 | ||
35 | - if (unlikely(err != NET_XMIT_SUCCESS)) { | |
36 | - if (net_xmit_drop_count(err)) { | |
37 | - qdisc_qstats_drop(sch); | |
38 | - qdisc_tree_reduce_backlog(sch, 1, | |
39 | - qdisc_pkt_len(skb)); | |
40 | - } | |
41 | + if (err != NET_XMIT_SUCCESS && | |
42 | + net_xmit_drop_count(err)) { | |
43 | + qdisc_qstats_drop(sch); | |
44 | + qdisc_tree_reduce_backlog(sch, 1, | |
45 | + pkt_len); | |
46 | } | |
47 | goto tfifo_dequeue; | |
48 | } |