netdev - [PATCH net 6/9] sch_fq_codel: avoid double free on init failure

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Date:   Wed, 30 Aug 2017 12:49:02 +0300
From:   Nikolay Aleksandrov <nikolay@...ulusnetworks.com>
To:     netdev@...r.kernel.org
Cc:     edumazet@...gle.com, jhs@...atatu.com, xiyou.wangcong@...il.com,
        jiri@...nulli.us, roopa@...ulusnetworks.com,
        Nikolay Aleksandrov <nikolay@...ulusnetworks.com>
Subject: [PATCH net 6/9] sch_fq_codel: avoid double free on init failure

It is very unlikely to happen but the backlogs memory allocation
could fail and will free q->flows, but then ->destroy() will free
q->flows too. For correctness remove the first free and let ->destroy
clean up.

Fixes: 87b60cfacf9f ("net_sched: fix error recovery at qdisc creation")
Signed-off-by: Nikolay Aleksandrov <nikolay@...ulusnetworks.com>
---
 net/sched/sch_fq_codel.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/net/sched/sch_fq_codel.c b/net/sched/sch_fq_codel.c
index 337f2d6d81e4..2c0c05f2cc34 100644
--- a/net/sched/sch_fq_codel.c
+++ b/net/sched/sch_fq_codel.c
@@ -491,10 +491,8 @@ static int fq_codel_init(struct Qdisc *sch, struct nlattr *opt)
 		if (!q->flows)
 			return -ENOMEM;
 		q->backlogs = kvzalloc(q->flows_cnt * sizeof(u32), GFP_KERNEL);
-		if (!q->backlogs) {
-			kvfree(q->flows);
+		if (!q->backlogs)
 			return -ENOMEM;
-		}
 		for (i = 0; i < q->flows_cnt; i++) {
 			struct fq_codel_flow *flow = q->flows + i;
 
-- 
2.1.4