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,USER_AGENT_SANE_1 autolearn=unavailable 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 5FFD0C433DF for ; Tue, 28 Jul 2020 10:54:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3895520714 for ; Tue, 28 Jul 2020 10:54:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728782AbgG1Kyo (ORCPT ); Tue, 28 Jul 2020 06:54:44 -0400 Received: from www62.your-server.de ([213.133.104.62]:49934 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728876AbgG1Kyo (ORCPT ); Tue, 28 Jul 2020 06:54:44 -0400 Received: from sslproxy02.your-server.de ([78.47.166.47]) by www62.your-server.de with esmtpsa (TLSv1.2:DHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89_1) (envelope-from ) id 1k0NFD-0004CE-Pr; Tue, 28 Jul 2020 12:54:03 +0200 Received: from [178.196.57.75] (helo=pc-9.home) by sslproxy02.your-server.de with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1k0NFD-000VJh-8W; Tue, 28 Jul 2020 12:54:03 +0200 Subject: Re: [Linux-kernel-mentees] [PATCH net v2] xdp: Prevent kernel-infoleak in xsk_getsockopt() To: Peilin Ye , Song Liu , =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= , Magnus Karlsson , Jonathan Lemon Cc: Dan Carpenter , Arnd Bergmann , Greg Kroah-Hartman , "David S. Miller" , Jakub Kicinski , Alexei Starovoitov , Jesper Dangaard Brouer , John Fastabend , Martin KaFai Lau , Yonghong Song , Andrii Nakryiko , KP Singh , linux-kernel-mentees@lists.linuxfoundation.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org References: <20200728022859.381819-1-yepeilin.cs@gmail.com> <20200728053604.404631-1-yepeilin.cs@gmail.com> From: Daniel Borkmann Message-ID: <916dbfd3-e601-c4be-41f0-97efc4aaa456@iogearbox.net> Date: Tue, 28 Jul 2020 12:53:59 +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: <20200728053604.404631-1-yepeilin.cs@gmail.com> 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 0.102.3/25886/Mon Jul 27 16:48:28 2020) Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On 7/28/20 7:36 AM, Peilin Ye wrote: > xsk_getsockopt() is copying uninitialized stack memory to userspace when > `extra_stats` is `false`. Fix it. > > Fixes: 8aa5a33578e9 ("xsk: Add new statistics") > Suggested-by: Dan Carpenter > Signed-off-by: Peilin Ye > --- > Doing `= {};` is sufficient since currently `struct xdp_statistics` is > defined as follows: > > struct xdp_statistics { > __u64 rx_dropped; > __u64 rx_invalid_descs; > __u64 tx_invalid_descs; > __u64 rx_ring_full; > __u64 rx_fill_ring_empty_descs; > __u64 tx_ring_empty_descs; > }; > > When being copied to the userspace, `stats` will not contain any > uninitialized "holes" between struct fields. I've added above explanation to the commit log since it's useful reasoning for later on 'why' something has been done a certain way. Applied, thanks Peilin!