lkml.org 
[lkml]   [2016]   [Jul]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.4 05/32] netem: fix a use after free
Date
4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Eric Dumazet <edumazet@google.com>

[ 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>
---
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;
}

\
 
 \ /
  Last update: 2016-07-07 03:41    [W:0.140 / U:32.004 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site