From: WANG Cong <xiyou.wangcong@gmail.com>
Date: Tue, 14 Jul 2015 18:21:57 +0000 (-0700)
Subject: net_sched: fix a use-after-free in sfq
X-Git-Tag: firefly_0821_release~176^2~1383^2~31
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=e8d092aafd9e68c04d7b468e95ff7a617998a796;p=firefly-linux-kernel-4.4.55.git

net_sched: fix a use-after-free in sfq

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>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
index 7d1492663360..52f75a5473e1 100644
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -306,10 +306,10 @@ 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;
 	}