[3.19.y-ckt stable] Patch "net_sched: fix a use-after-free in sfq" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    net_sched: fix a use-after-free in sfq

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt6.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 37e928b54a6c681037218bfebcf0276602824e31 Mon Sep 17 00:00:00 2001
From: WANG Cong <xiyou.wangcong at gmail.com>
Date: Tue, 14 Jul 2015 11:21:57 -0700
Subject: net_sched: fix a use-after-free in sfq

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