[PATCH 4.18 011/235] erspan: return PACKET_REJECT when the appropriate tunnel is not found

[Greg Kroah-Hartman]

4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Haishuang Yan <yanhaishuang@xxxxxxxxxxxxxxxxxxxx>

[ Upstream commit 5a64506b5c2c3cdb29d817723205330378075448 ]

If erspan tunnel hasn't been established, we'd better send icmp port
unreachable message after receive erspan packets.

Fixes: 84e54fe0a5ea ("gre: introduce native tunnel support for ERSPAN")
Cc: William Tu <u9012063@xxxxxxxxx>
Signed-off-by: Haishuang Yan <yanhaishuang@xxxxxxxxxxxxxxxxxxxx>
Acked-by: William Tu <u9012063@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 net/ipv4/ip_gre.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -331,6 +331,8 @@ static int erspan_rcv(struct sk_buff *sk
 		ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
 		return PACKET_RCVD;
 	}
+	return PACKET_REJECT;
+
 drop:
 	kfree_skb(skb);
 	return PACKET_RCVD;