From: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Date: Wed, 30 Aug 2017 09:49:04 +0000 (+0300)
Subject: sch_sfq: fix null pointer dereference on init failure
X-Git-Tag: v4.13~9^2~8^2~1
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=e232657661242cc8a169595160847b3e66aa7056;p=linux.git

sch_sfq: fix null pointer dereference on init failure

Currently only a memory allocation failure can lead to this, so let's
initialize the timer first.

Fixes: 6529eaba33f0 ("net: sched: introduce tcf block infractructure")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.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 82469ef9655e..fc69fc5956e9 100644
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -716,13 +716,13 @@ static int sfq_init(struct Qdisc *sch, struct nlattr *opt)
 	int i;
 	int err;
 
+	setup_deferrable_timer(&q->perturb_timer, sfq_perturbation,
+			       (unsigned long)sch);
+
 	err = tcf_block_get(&q->block, &q->filter_list);
 	if (err)
 		return err;
 
-	setup_deferrable_timer(&q->perturb_timer, sfq_perturbation,
-			       (unsigned long)sch);
-
 	for (i = 0; i < SFQ_MAX_DEPTH + 1; i++) {
 		q->dep[i].next = i + SFQ_MAX_FLOWS;
 		q->dep[i].prev = i + SFQ_MAX_FLOWS;