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=-5.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,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 01ACBC32771 for ; Wed, 22 Jan 2020 23:45:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C35BA21835 for ; Wed, 22 Jan 2020 23:45:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="NKu3MVBP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726442AbgAVXpi (ORCPT ); Wed, 22 Jan 2020 18:45:38 -0500 Received: from mail-pf1-f179.google.com ([209.85.210.179]:37956 "EHLO mail-pf1-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725911AbgAVXph (ORCPT ); Wed, 22 Jan 2020 18:45:37 -0500 Received: by mail-pf1-f179.google.com with SMTP id x185so593475pfc.5 for ; Wed, 22 Jan 2020 15:45:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=BsgFl0ZNFiD73iCKTJQPfPLfGgrqLNO0kJzFDpfi5rw=; b=NKu3MVBP4tv7QI7UHUo8YwSEIiROh1W1O21fs6umX9359qBnybevWLoDOhBsLHKIER KQ8M3HevaIBBvTE80H2VvgQGAWJwUEMuDU3s2fFp8JWsmS+l4JtXjHeZB6RJ6rs94FXZ S/2wtx5BYyHffZ/qE9p/VSDRttw064W3vlAXSq3q2R5rtP7dYrsYOQMA5Wgk2AZ8CKlH UrNn9PDMw5FyyiE39oNPYQNyckD2YBBe5Hbw1u9AGc0lblO5Y7UQvt76Vw6+ZU8iUGzl FG/J4JysYq+VZUWa7qawakGdQlgKMOoXAy/JPxjG0OmUMzU0dBl/p8TCSGKhL64ZqFvE sJAQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=BsgFl0ZNFiD73iCKTJQPfPLfGgrqLNO0kJzFDpfi5rw=; b=l/6MhJcLXCgzbKPoBFZi5uSr7OjXJ/HI4QHdmm6rE2l7rR2ve5jD1eMR1SNnCfJ31I N1+2gr2z8XQFPGXtIBc0U7l1O6fRbCv9sMrkxuvDHlBoJWBiCAquyCH/q+jR2YyA3ptJ ODMq9rATk+OLLpR4QBEPy1Dn6WAGPc7HyVQvtwOljE1Oddu4lP+wV8H5eiMcYw6pE12E 3MStkMktaSLb5ytsDFfJnhEjRwnJcpQwtBNgrK5Cw7QROP7mL+fNawLjZqKU08ygmW1f F0vpqwmPDhWKIYrTPiMQH0HqeDGiyYiRwRATT73Ja44r0j0cLrorlauzN2o4ga/yEJ+X JOAQ== X-Gm-Message-State: APjAAAVA97Amrb0wWy71PNMRg+m5nCqgpj0N0Y6+fwhw21QGGlSD2JLx sFaQ17Jf9t/yQRuoJpthnak= X-Google-Smtp-Source: APXvYqzK+i1yLSTifNBusAkg2T4wfsbHkYws0Ff4/O86aUuYFRky+tbglLvmKuHq8lk7cuGunjxIeA== X-Received: by 2002:a63:dc4f:: with SMTP id f15mr754863pgj.300.1579736736933; Wed, 22 Jan 2020 15:45:36 -0800 (PST) Received: from ?IPv6:2620:15c:2c1:200:55c7:81e6:c7d8:94b? ([2620:15c:2c1:200:55c7:81e6:c7d8:94b]) by smtp.gmail.com with ESMTPSA id i17sm54570pfr.67.2020.01.22.15.45.35 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 22 Jan 2020 15:45:36 -0800 (PST) Subject: Re: [Patch net] net_sched: fix datalen for ematch To: Cong Wang , netdev@vger.kernel.org Cc: syzbot+5af9a90dad568aa9f611@syzkaller.appspotmail.com, syzbot+2f07903a5b05e7f36410@syzkaller.appspotmail.com, Eric Dumazet References: <20200122234203.15441-1-xiyou.wangcong@gmail.com> From: Eric Dumazet Message-ID: <317521e6-07f5-c32a-66dd-8aa499ae80d7@gmail.com> Date: Wed, 22 Jan 2020 15:45:34 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <20200122234203.15441-1-xiyou.wangcong@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 1/22/20 3:42 PM, Cong Wang wrote: > syzbot reported an out-of-bound access in em_nbyte. As initially > analyzed by Eric, this is because em_nbyte sets its own em->datalen > in em_nbyte_change() other than the one specified by user, but this > value gets overwritten later by its caller tcf_em_validate(). > We should leave em->datalen untouched to respect their choices. > > I audit all the in-tree ematch users, all of those implement > ->change() set em->datalen, so we can just avoid setting it twice > in this case. > > Reported-and-tested-by: syzbot+5af9a90dad568aa9f611@syzkaller.appspotmail.com > Reported-by: syzbot+2f07903a5b05e7f36410@syzkaller.appspotmail.com > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > Cc: Eric Dumazet > Signed-off-by: Cong Wang > --- > SGTM, thanks. Reviewed-by: Eric Dumazet