From: Paolo Abeni <[email protected]>
Date: Mon, 9 Oct 2017 14:52:10 +0200
> The commit bc044e8db796 ("udp: perform source validation for
> mcast early demux") does not take into account that broadcast packets
> lands in the same code path and they need different checks for the
> source address - notably, zero source address are valid for bcast
> and invalid for mcast.
>
> As a result, 2nd and later broadcast packets with 0 source address
> landing to the same socket are dropped. This breaks dhcp servers.
>
> Since we don't have stringent performance requirements for ingress
> broadcast traffic, fix it by disabling UDP early demux such traffic.
>
> Reported-by: Hannes Frederic Sowa <[email protected]>
> Fixes: bc044e8db796 ("udp: perform source validation for mcast early demux")
> Signed-off-by: Paolo Abeni <[email protected]>
Applied and queued up for -stable.
