From e4acf4274169fb6106d4ac854c87071b9764a00d Mon Sep 17 00:00:00 2001
From: Colin Ian King <colin.king@canonical.com>
Date: Sun, 5 May 2019 22:50:19 +0100
Subject: [PATCH] taprio: add null check on sched_nest to avoid potential null
pointer dereference
The call to nla_nest_start_noflag can return a null pointer and currently
this is not being checked and this can lead to a null pointer dereference
when the null pointer sched_nest is passed to function nla_nest_end. Fix
this by adding in a null pointer check.
Addresses-Coverity: ("Dereference null return value")
Fixes: a3d43c0d56f1 ("taprio: Add support adding an admin schedule")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/sched/sch_taprio.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
index 539677120b9f6..9ecfb8f5902a4 100644
--- a/net/sched/sch_taprio.c
+++ b/net/sched/sch_taprio.c
@@ -1087,6 +1087,8 @@ static int taprio_dump(struct Qdisc *sch, struct sk_buff *skb)
goto done;
sched_nest = nla_nest_start_noflag(skb, TCA_TAPRIO_ATTR_ADMIN_SCHED);
+ if (!sched_nest)
+ goto options_error;
if (dump_schedule(skb, admin))
goto admin_error;
--
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