From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 74122C433E0 for ; Fri, 31 Jul 2020 00:07:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4AC2F2082E for ; Fri, 31 Jul 2020 00:07:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730793AbgGaAHr (ORCPT ); Thu, 30 Jul 2020 20:07:47 -0400 Received: from www62.your-server.de ([213.133.104.62]:46030 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730786AbgGaAHq (ORCPT ); Thu, 30 Jul 2020 20:07:46 -0400 Received: from sslproxy06.your-server.de ([78.46.172.3]) by www62.your-server.de with esmtpsa (TLSv1.2:DHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89_1) (envelope-from ) id 1k1IaM-0007C3-P9; Fri, 31 Jul 2020 02:07:42 +0200 Received: from [178.196.57.75] (helo=pc-9.home) by sslproxy06.your-server.de with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1k1IaM-0007Me-IO; Fri, 31 Jul 2020 02:07:42 +0200 Subject: Re: [PATCH net] net/bpfilter: initialize pos in __bpfilter_process_sockopt To: Christian Brauner , Christoph Hellwig Cc: davem@davemloft.net, kuba@kernel.org, ast@kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, Rodrigo Madera References: <20200730160900.187157-1-hch@lst.de> <20200730161303.erzgrhqsgc77d4ny@wittgenstein> From: Daniel Borkmann Message-ID: <03954b8f-0db7-427b-cfd6-7146da9b5466@iogearbox.net> Date: Fri, 31 Jul 2020 02:07:42 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <20200730161303.erzgrhqsgc77d4ny@wittgenstein> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Authenticated-Sender: daniel@iogearbox.net X-Virus-Scanned: Clear (ClamAV 0.102.3/25889/Thu Jul 30 17:03:53 2020) Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On 7/30/20 6:13 PM, Christian Brauner wrote: > On Thu, Jul 30, 2020 at 06:09:00PM +0200, Christoph Hellwig wrote: >> __bpfilter_process_sockopt never initialized the pos variable passed to >> the pipe write. This has been mostly harmless in the past as pipes >> ignore the offset, but the switch to kernel_write no verified the > > s/no/now/ > >> position, which can lead to a failure depending on the exact stack >> initialization patter. Initialize the variable to zero to make > > s/patter/pattern/ > >> rw_verify_area happy. >> >> Fixes: 6955a76fbcd5 ("bpfilter: switch to kernel_write") >> Reported-by: Christian Brauner >> Reported-by: Rodrigo Madera >> Signed-off-by: Christoph Hellwig >> Tested-by: Rodrigo Madera >> --- > > Thanks for tracking this down, Christoph! This fixes the logging issue > for me. > Tested-by: Christian Brauner > Reviewed-by: Christian Brauner Applied to bpf & fixed up the typos in the commit msg, thanks everyone!