From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1952229AbdDYRzx (ORCPT ); Tue, 25 Apr 2017 13:55:53 -0400 Received: from shards.monkeyblade.net ([184.105.139.130]:43130 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1952027AbdDYRzp (ORCPT ); Tue, 25 Apr 2017 13:55:45 -0400 Date: Tue, 25 Apr 2017 13:55:43 -0400 (EDT) Message-Id: <20170425.135543.1706004185593424024.davem@davemloft.net> To: glider@google.com Cc: dvyukov@google.com, kcc@google.com, edumazet@google.com, kuznet@ms2.inr.ac.ru, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH] ipv6: ensure message length for raw socket is at least sizeof(ipv6hdr) From: David Miller In-Reply-To: <20170425131827.66498-1-glider@google.com> References: <20170425131827.66498-1-glider@google.com> 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]); Tue, 25 Apr 2017 10:14:20 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Alexander Potapenko Date: Tue, 25 Apr 2017 15:18:27 +0200 > rawv6_send_hdrinc() expects that the buffer copied from the userspace > contains the IPv6 header, so if too few bytes are copied parts of the > header may remain uninitialized. > > This bug has been detected with KMSAN. > > Signed-off-by: Alexander Potapenko Hmmm, ipv4 seems to lack this check as well. I think we need to be careful here and fully understand why KMSAN doesn't seem to be triggering in the ipv4 case but for ipv6 it is before I apply this. Thanks.