From: Guillaume Nault gnault@redhat.com
commit f7716b318568b22fbf0e3be99279a979e217cf71 upstream.
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: 962924fa2b7a ("ip_gre: Refactor collect metatdata mode tunnel xmit to ip_md_tunnel_xmit") Signed-off-by: Guillaume Nault gnault@redhat.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv4/ip_gre.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -577,8 +577,9 @@ static int gre_fill_metadata_dst(struct
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);