[PATCH 1/2] ip_gre: fix potential memory leak in erspan_rcv

[Haishuang Yan]

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

Fixes: 84e54fe0a5ea ("gre: introduce native tunnel support for ERSPAN")
Cc: William Tu <u9012063@xxxxxxxxx>
Signed-off-by: Haishuang Yan <yanhaishuang@xxxxxxxxxxxxxxxxxxxx>
---
 net/ipv4/ip_gre.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index d828821..9253d6f 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -304,8 +304,10 @@ 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;
-- 
1.8.3.1