[PATCH 3.19.y-ckt 068/130] fq_codel: fix a use-after-free

[Kamal Mostafa]

3.19.8-ckt6 -stable review patch.  If anyone has any objections, please let me know.

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

From: WANG Cong <xiyou.wangcong at gmail.com>

commit 052cbda41fdc243a8d40cce7ab3a6327b4b2887e upstream.

Fixes: 25331d6ce42b ("net: sched: implement qstat helper routines")
Cc: John Fastabend <john.fastabend at gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong at gmail.com>
Signed-off-by: Cong Wang <cwang at twopensource.com>
Acked-by: Eric Dumazet <edumazet at google.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 net/sched/sch_fq_codel.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sched/sch_fq_codel.c b/net/sched/sch_fq_codel.c
index 1e52dec..b61fd84 100644
--- a/net/sched/sch_fq_codel.c
+++ b/net/sched/sch_fq_codel.c
@@ -162,10 +162,10 @@ 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;
 }
-- 
1.9.1