ip_gre: fix error path when erspan_rcv failed

[ 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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 1933654..c872be8 100644 (file)
--- 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);