From: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Date: Wed, 20 Dec 2017 02:07:00 +0000 (+0800)
Subject: ip_gre: fix potential memory leak in erspan_rcv
X-Git-Tag: v4.15.13~22
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=70559f800f6267303d896f33b18607b6b1896d86;p=thirdparty%2Fkernel%2Fstable.git

ip_gre: fix potential memory leak in erspan_rcv


[ Upstream commit 50670b6ee9bc4ae8f9ce3112b437987adf273245 ]

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

Fixes: 1a66a836da6 ("gre: add collect_md mode to ERSPAN tunnel")
Cc: William Tu <u9012063@gmail.com>
Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index e05bca0e61fc7..01bbbfe2c2a7a 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -303,8 +303,10 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
 				return PACKET_REJECT;
 
 			md = ip_tunnel_info_opts(&tun_dst->u.tun_info);
-			if (!md)
+			if (!md) {
+				dst_release((struct dst_entry *)tun_dst);
 				return PACKET_REJECT;
+			}
 
 			md->index = index;
 			info = &tun_dst->u.tun_info;