From 469f87e158628fe66dcbbce9dd5e7b7acfe934a9 Mon Sep 17 00:00:00 2001
From: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Date: Thu, 15 Jun 2017 10:29:29 +0800
Subject: [PATCH] ip_tunnel: fix potential issue in ip_tunnel_rcv

When ip_tunnel_rcv fails, the tun_dst won't be freed, so call
dst_release to free it in error code path.

Fixes: 2e15ea390e6f ("ip_gre: Add support to collect tunnel metadata.")
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Tested-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/ipv4/ip_tunnel.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index b436d0775631..129d1a3616f8 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -446,6 +446,8 @@ int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
 	return 0;
 
 drop:
+	if (tun_dst)
+		dst_release((struct dst_entry *)tun_dst);
 	kfree_skb(skb);
 	return 0;
 }