[PATCH 3.19.y-ckt 052/130] net_sched: fix a use-after-free in sfq

[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 e8d092aafd9e68c04d7b468e95ff7a617998a796 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>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 net/sched/sch_sfq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
index b877140..0f65ba4 100644
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -329,10 +329,10 @@ drop:
 		len = qdisc_pkt_len(skb);
 		slot->backlog -= len;
 		sfq_dec(q, x);
-		kfree_skb(skb);
 		sch->q.qlen--;
 		qdisc_qstats_drop(sch);
 		qdisc_qstats_backlog_dec(sch, skb);
+		kfree_skb(skb);
 		return len;
 	}
 
-- 
1.9.1