From: Alexander Ovechkin ovov@yandex-team.ru
[ Upstream commit 9e7c5b396e98eed859d3dd1ab235912a296faab5 ]
ip6_tnl_encap assigns to proto transport protocol which encapsulates inner packet, but we must pass to set_inner_ipproto protocol of that inner packet.
Calling set_inner_ipproto after ip6_tnl_encap might break gso. For example, in case of encapsulating ipv6 packet in fou6 packet, inner_ipproto would be set to IPPROTO_UDP instead of IPPROTO_IPV6. This would lead to incorrect calling sequence of gso functions: ipv6_gso_segment -> udp6_ufo_fragment -> skb_udp_tunnel_segment -> udp6_ufo_fragment instead of: ipv6_gso_segment -> udp6_ufo_fragment -> skb_udp_tunnel_segment -> ip6ip6_gso_segment
Fixes: 6c11fbf97e69 ("ip6_tunnel: add MPLS transmit support") Signed-off-by: Alexander Ovechkin ovov@yandex-team.ru Link: https://lore.kernel.org/r/20201029171012.20904-1-ovov@yandex-team.ru Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv6/ip6_tunnel.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -1271,6 +1271,8 @@ route_lookup: if (max_headroom > dev->needed_headroom) dev->needed_headroom = max_headroom;
+ skb_set_inner_ipproto(skb, proto); + err = ip6_tnl_encap(skb, t, &proto, fl6); if (err) return err; @@ -1280,8 +1282,6 @@ route_lookup: ipv6_push_frag_opts(skb, &opt.ops, &proto); }
- skb_set_inner_ipproto(skb, proto); - skb_push(skb, sizeof(struct ipv6hdr)); skb_reset_network_header(skb); ipv6h = ipv6_hdr(skb);