From: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Date: Wed, 20 Dec 2017 02:21:46 +0000 (+0800)
Subject: ip_gre: fix error path when erspan_rcv failed
X-Git-Tag: for-linus-20180210~31^2~314
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=dd8d5b8c5b22e31079b259b8bfb686f1fac1080a;p=linux-block.git

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>
---

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index fd4d6e96da7e..5c36b6745dbc 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);