From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net] udp: prevent bugcheck if filter truncates packet too much Date: Mon, 11 Jul 2016 12:43:48 -0700 (PDT) Message-ID: <20160711.124348.2217222752892197777.davem@davemloft.net> References: <20160708155233.C78AAA0ECC@unicorn.suse.cz> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: samanthakumar@google.com, marco.gra@gmail.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kuznet@ms2.inr.ac.ru, jmorris@namei.org, yoshfuji@linux-ipv6.org, kaber@trash.net To: mkubecek@suse.cz Return-path: In-Reply-To: <20160708155233.C78AAA0ECC@unicorn.suse.cz> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Michal Kubecek 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 > Signed-off-by: Michal Kubecek Applied and queued up for -stable, thanks.