From: Nikolay Aleksandrov <nikolay@xxxxxxxxxxxxxxxxxxx>
Date: Sun, 2 Aug 2020 15:50:39 +0300
> We need to clear all of the bridge private skb variables as they can be
> stale due to the packet having skb->cb initialized earlier and then
> transmitted through the bridge device. Similar memset is already done on
> bridge's input. We've seen cases where proxyarp_replied was 1 on routed
> multicast packets transmitted through the bridge to ports with neigh
> suppress and were getting dropped. Same thing can in theory happen with the
> port isolation bit as well. We clear only the struct part after the bridge
> pointer (currently 8 bytes) since the pointer is always set later.
> We can now remove the redundant zeroing of frag_max_size.
> Also add a BUILD_BUG_ON to make sure we catch any movement of the bridge
> dev pointer.
>
> Fixes: 821f1b21cabb ("bridge: add new BR_NEIGH_SUPPRESS port flag to suppress arp and nd flood")
> Signed-off-by: Nikolay Aleksandrov <nikolay@xxxxxxxxxxxxxxxxxxx>
Nikolay, I applied v1 already as I'm not at all against the full clear.
