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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 2559CC7618B for ; Mon, 29 Jul 2019 08:25:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E7F13206E0 for ; Mon, 29 Jul 2019 08:25:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="qwWgHodv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727628AbfG2IZm (ORCPT ); Mon, 29 Jul 2019 04:25:42 -0400 Received: from mail-pl1-f194.google.com ([209.85.214.194]:46374 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727241AbfG2IZm (ORCPT ); Mon, 29 Jul 2019 04:25:42 -0400 Received: by mail-pl1-f194.google.com with SMTP id c2so27187099plz.13; Mon, 29 Jul 2019 01:25:41 -0700 (PDT) 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-transfer-encoding:content-language; bh=NH4lN7mu8BOKkfv6t88t7ZhBrCg11QlAHHEp1XAW710=; b=qwWgHodvvihYWDb0UOMMmCxPqDWo3t6/8zVyQ7tP749NrTsPt5HMs7KWdu3nXGkmj8 SpQS8XhQBvxpZ0KOv/qBD8tdrtdMesvjtq/kvBfQotUqqq0TTbqcj0j/mZ/BIPPD2p4P cnfYdlJtNcQSWyAb6CsaWUZmTCnFfwiAE7nHfUaDL5a/w7xg/c05bfZxccDpI3CLzTt5 T5spntzFBadJb4y9sC8zVNI2mgHz94lOWLcGEp0OfLvP2I2oCvAdipuyXkTeDam+Cgz8 hwjXLE8f4UNj+b7HKD6dqt9QU/n4gZ/9/nxLj8HFtL0StrgZzw/RuJuz+s6TE54KFUKV seWQ== 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-transfer-encoding :content-language; bh=NH4lN7mu8BOKkfv6t88t7ZhBrCg11QlAHHEp1XAW710=; b=YB5OgKzkD4oEuFuObguYmJCVssZC7TGuE8dHY6AncFEDwPXUKYdstvlxjqaFIS2uVM 2MFFpMEJ7TbOxG2CUz0rWCmhiog8js02/w+iquhRPHy+48ODdOtm8I9evDI6JVrJg9+H xOUXzC7fg9/oUo810kgEszxikavxG2ZGAj2bjDnxBJS/1HfJd6koU5XzV10L0xN17Aqx Nr8Syapf5DZrM14mONxGcJnrcAiRJTpqlh37Ik/gl63gnzCHFW7EiZXSVN4MyOsnYaTy ei8Yl/dNkave5+JS5KiP5n/ss5Wue2unEvBuaaH00sirAaqbCtLOjOtjHsfOqRA5tPYB UovQ== X-Gm-Message-State: APjAAAWzIFbyoclVgejxHKf9Hfr0C4C9siPM1eeWJqm+awV4nh5QUn8n Gbk9Ys02gv3utOC9SF/RxJOVLsh+AKc= X-Google-Smtp-Source: APXvYqzUL8MoUKRpHICLcWOcctUAGjZsDzWU9jLkSmVyIZRBrM4Kv24LNMtcqZFN1hX61REQ3ly6Cw== X-Received: by 2002:a17:902:7887:: with SMTP id q7mr110530731pll.129.1564388741261; Mon, 29 Jul 2019 01:25:41 -0700 (PDT) Received: from ?IPv6:2402:f000:4:72:808::177e? ([2402:f000:4:72:808::177e]) by smtp.gmail.com with ESMTPSA id w132sm62425631pfd.78.2019.07.29.01.25.39 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 29 Jul 2019 01:25:40 -0700 (PDT) Subject: Re: [PATCH v2] net: sched: Fix a possible null-pointer dereference in dequeue_func() To: Jiri Pirko Cc: jhs@mojatatu.com, xiyou.wangcong@gmail.com, davem@davemloft.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: <20190729080018.28678-1-baijiaju1990@gmail.com> <20190729081854.GC2211@nanopsycho> From: Jia-Ju Bai Message-ID: <4619ec69-b800-1a61-7082-85ef4fa9af74@gmail.com> Date: Mon, 29 Jul 2019 16:25:41 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190729081854.GC2211@nanopsycho> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2019/7/29 16:18, Jiri Pirko wrote: > Mon, Jul 29, 2019 at 10:00:18AM CEST, baijiaju1990@gmail.com wrote: >> In dequeue_func(), there is an if statement on line 74 to check whether >> skb is NULL: >> if (skb) >> >> When skb is NULL, it is used on line 77: >> prefetch(&skb->end); >> >> Thus, a possible null-pointer dereference may occur. >> >> To fix this bug, skb->end is used when skb is not NULL. >> >> This bug is found by a static analysis tool STCheck written by us. >> >> Fixes: 79bdc4c862af ("codel: generalize the implementation") > Looks like this is something being there since the beginning: > commit 76e3cc126bb223013a6b9a0e2a51238d1ef2e409 > Author: Eric Dumazet > Date: Thu May 10 07:51:25 2012 +0000 > > codel: Controlled Delay AQM > > > Please adjust "Fixes:". Thanks for the advice :) I have sent a v3 patch. Best wishes, Jia-Ju Bai