[PATCH AUTOSEL for 4.14 54/67] ip_gre: fix error path when erspan_rcv failed

Sasha Levin
2018-03-08T06:37:35Z

From: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>

[ Upstream commit dd8d5b8c5b22e31079b259b8bfb686f1fac1080a ]

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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
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 045331204097..e0cc6a38b701 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -408,11 +408,13 @@ static int gre_rcv(struct sk_buff *skb)
if (unlikely(tpi.proto == htons(ETH_P_ERSPAN))) {
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);
--
2.14.1