From: WANG Cong <xiyou.wangcong@gmail.com>
Date: Mon, 13 Jul 2015 19:30:07 +0000 (-0700)
Subject: fq_codel: fix a use-after-free
X-Git-Tag: v4.9.8~3868^2~36
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=052cbda41fdc243a8d40cce7ab3a6327b4b2887e;p=platform%2Fkernel%2Flinux-rpi3.git

fq_codel: fix a use-after-free

Fixes: 25331d6ce42b ("net: sched: implement qstat helper routines")
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/sched/sch_fq_codel.c b/net/sched/sch_fq_codel.c
index d75993f..06e7c84 100644
--- a/net/sched/sch_fq_codel.c
+++ b/net/sched/sch_fq_codel.c
@@ -155,10 +155,10 @@ static unsigned int fq_codel_drop(struct Qdisc *sch)
 	skb = dequeue_head(flow);
 	len = qdisc_pkt_len(skb);
 	q->backlogs[idx] -= len;
-	kfree_skb(skb);
 	sch->q.qlen--;
 	qdisc_qstats_drop(sch);
 	qdisc_qstats_backlog_dec(sch, skb);
+	kfree_skb(skb);
 	flow->dropped++;
 	return idx;
 }