On Sat, Jul 9, 2016 at 6:43 AM, Michal Kubecek <mkube...@suse.cz> wrote: > On Sat, Jul 09, 2016 at 11:48:49AM +0200, Daniel Borkmann wrote: >> On 07/09/2016 02:20 AM, Alexei Starovoitov wrote: >> >On Sat, Jul 09, 2016 at 01:31:40AM +0200, Eric Dumazet wrote: >> >>On Fri, 2016-07-08 at 17:52 +0200, Michal Kubecek wrote: >> >>>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....@gmail.com> >> >>>Signed-off-by: Michal Kubecek <mkube...@suse.cz> >> >>>--- > >> >>Acked-by: Eric Dumazet <eduma...@google.com> >> > >> >this is incomplete fix. Please do not apply. See discussion at >> >security@kernel >> >> Ohh well, didn't see it earlier before starting the discussion at >> security@... >> >> I'm okay if we take this for now as a quick band aid and find a better >> way how to deal with the underlying issue long-term so that it's >> /guaranteed/ that it doesn't bite us any further in such fragile ways. > > Agreed. As rc7 is due in a day or two, rushing a complex and intrusive > solution in might be too risky.
Acked-by: Willem de Bruijn <will...@google.com> Thanks, Michal.