From: Ido Schimmel idosch@mellanox.com Date: Mon, 19 Nov 2018 16:11:07 +0000
From: Petr Machata petrm@mellanox.com
When a packet is trapped and the corresponding SKB marked as already-forwarded, it retains this marking even after it is forwarded across veth links into another bridge. There, since it ingresses the bridge over veth, which doesn't have offload_fwd_mark, it triggers a warning in nbp_switchdev_frame_mark().
Then nbp_switchdev_allowed_egress() decides not to allow egress from this bridge through another veth, because the SKB is already marked, and the mark (of 0) of course matches. Thus the packet is incorrectly blocked.
Solve by resetting offload_fwd_mark() in skb_scrub_packet(). That function is called from tunnels and also from veth, and thus catches the cases where traffic is forwarded between bridges and transformed in a way that invalidates the marking.
Signed-off-by: Petr Machata petrm@mellanox.com Suggested-by: Ido Schimmel idosch@mellanox.com Signed-off-by: Ido Schimmel idosch@mellanox.com
As a bug fix this seems relevant for 'net' instead of 'net-next'.