Re: [PATCH net] udp: prevent bugcheck if filter truncates packet too much

[David Miller]

From: Michal Kubecek <mkubecek@xxxxxxx>
Date: Fri,  8 Jul 2016 17:52:33 +0200 (CEST)

> If socket filter truncates an udp packet below the length of UDP header
> in udpv6_queue_rcv_skb() or udp_queue_rcv_skb(), it will trigger a
> BUG_ON in skb_pull_rcsum(). This BUG_ON (and therefore a system crash if
> kernel is configured that way) can be easily enforced by an unprivileged
> user which was reported as CVE-2016-6162. For a reproducer, see
> http://seclists.org/oss-sec/2016/q3/8
> 
> Fixes: e6afc8ace6dd ("udp: remove headers from UDP packets before queueing")
> Reported-by: Marco Grassi <marco.gra@xxxxxxxxx>
> Signed-off-by: Michal Kubecek <mkubecek@xxxxxxx>

Applied and queued up for -stable, thanks.