Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1432593AbdDYSGQ (ORCPT ); Tue, 25 Apr 2017 14:06:16 -0400 Received: from shards.monkeyblade.net ([184.105.139.130]:43254 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1432573AbdDYSGG (ORCPT ); Tue, 25 Apr 2017 14:06:06 -0400 Date: Tue, 25 Apr 2017 14:06:04 -0400 (EDT) Message-Id: <20170425.140604.276789553615920800.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] net/packet: check length in getsockopt() called with PACKET_HDRLEN From: David Miller In-Reply-To: <20170425165146.25075-1-glider@google.com> References: <20170425165146.25075-1-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 10:24:41 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 494 Lines: 13 From: Alexander Potapenko Date: Tue, 25 Apr 2017 18:51:46 +0200 > In the case getsockopt() is called with PACKET_HDRLEN and optlen < 4 > |val| remains uninitialized and the syscall may behave differently > depending on its value, and even copy garbage to userspace on certain > architectures. To fix this we now return -EINVAL if optlen is too small. > > This bug has been detected with KMSAN. > > Signed-off-by: Alexander Potapenko Applied, thanks.