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=-10.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,NICE_REPLY_A,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 0FA52C432BE for ; Mon, 2 Aug 2021 19:15:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D92DB60F93 for ; Mon, 2 Aug 2021 19:15:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229551AbhHBTPf (ORCPT ); Mon, 2 Aug 2021 15:15:35 -0400 Received: from gateway22.websitewelcome.com ([192.185.47.48]:11083 "EHLO gateway22.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229716AbhHBTPe (ORCPT ); Mon, 2 Aug 2021 15:15:34 -0400 Received: from cm14.websitewelcome.com (cm14.websitewelcome.com [100.42.49.7]) by gateway22.websitewelcome.com (Postfix) with ESMTP id D44BD2D7D4 for ; Mon, 2 Aug 2021 14:15:03 -0500 (CDT) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id AdN0m483G7sOiAdN0mgWPS; Mon, 02 Aug 2021 14:13:02 -0500 X-Authority-Reason: nr=8 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=embeddedor.com; s=default; h=Content-Transfer-Encoding:Content-Type: In-Reply-To:MIME-Version:Date:Message-ID:References:Cc:To:From:Subject:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=DJIS+a5HsMmnfIxc2Pzhsn+S1rqEqCOqgc6RlnNWJ6o=; b=EBYUsbVyp+HjHZwcH9ALnmg6Fi uqEN3Dltc7+UHmEwSBAJhyMK9ZKspqWrC8PHilc2jJro+1UWv1pWzRS1uW+kbZ16KM6ewHjGHIPi3 gIVHwcI5+GU0K5HQwLswTkbVNGeWWfWU3F2JvH+b8+fs/pT19NRPP8sd1HF4iKNAEAXmBxftqUvgt XDJC7lHqzTRCj7WxZAthwVGTn6YaaidkZb56AK+i9VuRjBDcwucB+jRT8DjP7+tCkc4//pUvk5Mcq FkPYAjy7URIh/9jGAB3X5QXrT7c4AMnpvN3vNJ19LzKgK0J48BoTWug6ec+dACL9Z469kbuyXgUX3 /zl0ZXnw==; Received: from 187-162-31-110.static.axtel.net ([187.162.31.110]:57696 helo=[192.168.15.8]) by gator4166.hostgator.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94.2) (envelope-from ) id 1mAdMy-0042EB-Mo; Mon, 02 Aug 2021 14:13:00 -0500 Subject: Re: [PATCH][next] net/ipv4: Replace one-element array with flexible-array member From: "Gustavo A. R. Silva" To: patchwork-bot+netdevbpf@kernel.org, "Gustavo A. R. Silva" Cc: davem@davemloft.net, kuba@kernel.org, yoshfuji@linux-ipv6.org, dsahern@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org References: <20210731170830.GA48844@embeddedor> <162791400741.18419.5941105433257893840.git-patchwork-notify@kernel.org> <6d3c2ba1-ea01-dbc1-1e18-1ba9c7a15181@embeddedor.com> Message-ID: <4a9987c1-1f7a-35af-af6a-01b96292d2ee@embeddedor.com> Date: Mon, 2 Aug 2021 14:15:40 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <6d3c2ba1-ea01-dbc1-1e18-1ba9c7a15181@embeddedor.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 187.162.31.110 X-Source-L: No X-Exim-ID: 1mAdMy-0042EB-Mo X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: 187-162-31-110.static.axtel.net ([192.168.15.8]) [187.162.31.110]:57696 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 10 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org On 8/2/21 13:46, Gustavo A. R. Silva wrote: > > > On 8/2/21 09:20, patchwork-bot+netdevbpf@kernel.org wrote: >> Hello: >> >> This patch was applied to netdev/net-next.git (refs/heads/master): >> >> On Sat, 31 Jul 2021 12:08:30 -0500 you wrote: >>> There is a regular need in the kernel to provide a way to declare having >>> a dynamically sized set of trailing elements in a structure. Kernel code >>> should always use “flexible array members”[1] for these cases. The older >>> style of one-element or zero-length arrays should no longer be used[2]. >>> >>> Use an anonymous union with a couple of anonymous structs in order to >>> keep userspace unchanged: >>> >>> [...] >> >> Here is the summary with links: >> - [next] net/ipv4: Replace one-element array with flexible-array member >> https://git.kernel.org/netdev/net-next/c/2d3e5caf96b9 > > arghh... this has a bug. Sorry, Dave. I will send a fix for this, shortly. > BTW... can we expect msf->imsf_numsrc to be zero at some point in the following pieces of code? net/ipv4/igmp.c: 2553 copycount = count < msf->imsf_numsrc ? count : msf->imsf_numsrc; 2554 len = copycount * sizeof(psl->sl_addr[0]); 2555 msf->imsf_numsrc = count; 2556 if (put_user(IP_MSFILTER_SIZE(copycount), optlen) || 2557 copy_to_user(optval, msf, IP_MSFILTER_SIZE(0))) { 2558 return -EFAULT; 2559 } net/ipv4/ip_sockglue.c: 1228 case IP_MSFILTER: 1229 { 1230 struct ip_msfilter *msf; 1231 1232 if (optlen < IP_MSFILTER_SIZE(0)) 1233 goto e_inval; 1234 if (optlen > sysctl_optmem_max) { 1235 err = -ENOBUFS; 1236 break; 1237 } 1238 msf = memdup_sockptr(optval, optlen); 1239 if (IS_ERR(msf)) { ... 1250 if (IP_MSFILTER_SIZE(msf->imsf_numsrc) > optlen) { 1251 kfree(msf); 1252 err = -EINVAL; 1253 break; 1254 } 1255 err = ip_mc_msfilter(sk, msf, 0); 1256 kfree(msf); 1257 break; 1258 } Thanks -- Gustavo