From: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Date: Wed, 20 Dec 2017 02:07:01 +0000 (+0800)
Subject: ip6_gre: fix potential memory leak in ip6erspan_rcv
X-Git-Tag: v4.16-rc1~123^2~311
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=afb4c97d90e62f33b9f389aa0023f8478bb89db2;p=thirdparty%2Fkernel%2Flinux.git

ip6_gre: fix potential memory leak in ip6erspan_rcv

If md is NULL, tun_dst must be freed, otherwise it will cause memory
leak.

Fixes: ef7baf5e083c ("ip6_gre: add ip6 erspan collect_md mode")
Cc: William Tu <u9012063@gmail.com>
Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index b7a79ddcf8516..8451d00b210bc 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -550,8 +550,10 @@ static int ip6erspan_rcv(struct sk_buff *skb, int gre_hdr_len,
 
 			info = &tun_dst->u.tun_info;
 			md = ip_tunnel_info_opts(info);
-			if (!md)
+			if (!md) {
+				dst_release((struct dst_entry *)tun_dst);
 				return PACKET_REJECT;
+			}
 
 			memcpy(md, pkt_md, sizeof(*md));
 			md->version = ver;