From dd8d5b8c5b22e31079b259b8bfb686f1fac1080a Mon Sep 17 00:00:00 2001
From: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Date: Wed, 20 Dec 2017 10:21:46 +0800
Subject: [PATCH] ip_gre: fix error path when erspan_rcv failed

When erspan_rcv call return PACKET_REJECT, we shoudn't call ipgre_rcv to
process packets again, instead send icmp unreachable message in error
path.

Fixes: 84e54fe0a5ea ("gre: introduce native tunnel support for ERSPAN")
Acked-by: William Tu <u9012063@gmail.com>
Cc: William Tu <u9012063@gmail.com>
Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/ipv4/ip_gre.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index fd4d6e96da7e9..5c36b6745dbce 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -434,11 +434,13 @@ static int gre_rcv(struct sk_buff *skb)
 		     tpi.proto == htons(ETH_P_ERSPAN2))) {
 		if (erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
 			return 0;
+		goto out;
 	}
 
 	if (ipgre_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
 		return 0;
 
+out:
 	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
 drop:
 	kfree_skb(skb);
-- 
2.30.2