From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752277AbcGKTnz (ORCPT ); Mon, 11 Jul 2016 15:43:55 -0400 Received: from shards.monkeyblade.net ([184.105.139.130]:59622 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750968AbcGKTny (ORCPT ); Mon, 11 Jul 2016 15:43:54 -0400 Date: Mon, 11 Jul 2016 12:43:48 -0700 (PDT) Message-Id: <20160711.124348.2217222752892197777.davem@davemloft.net> To: mkubecek@suse.cz 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 Subject: Re: [PATCH net] udp: prevent bugcheck if filter truncates packet too much From: David Miller In-Reply-To: <20160708155233.C78AAA0ECC@unicorn.suse.cz> References: <20160708155233.C78AAA0ECC@unicorn.suse.cz> X-Mailer: Mew version 6.7 on Emacs 24.5 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Mon, 11 Jul 2016 12:43:49 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@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.