Commit f7716b31 authored by Guillaume Nault's avatar Guillaume Nault Committed by Jakub Kicinski
Browse files

gre: Don't accidentally set RTO_ONLINK in gre_fill_metadata_dst() 



Mask the ECN bits before initialising ->flowi4_tos. The tunnel key may
have the last ECN bit set, which will interfere with the route lookup
process as ip_route_output_key_hash() interpretes this bit specially
(to restrict the route scope).

Found by code inspection, compile tested only.

Fixes: 962924fa ("ip_gre: Refactor collect metatdata mode tunnel xmit to ip_md_tunnel_xmit")
Signed-off-by: default avatarGuillaume Nault <gnault@redhat.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 23e7b1bf

net/ipv4/ip_gre.c

+3 −2
Original line number Diff line number Diff line
@@ -604,8 +604,9 @@ static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb) 


	key = &info->key;

	ip_tunnel_init_flow(&fl4, IPPROTO_GRE, key->u.ipv4.dst, key->u.ipv4.src,

			    tunnel_id_to_key32(key->tun_id), key->tos, 0,

			    skb->mark, skb_get_hash(skb));

			    tunnel_id_to_key32(key->tun_id),

			    key->tos & ~INET_ECN_MASK, 0, skb->mark,

			    skb_get_hash(skb));

	rt = ip_route_output_key(dev_net(dev), &fl4);

	if (IS_ERR(rt))

		return PTR_ERR(rt);