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=-2.3 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 12FE7C47404 for ; Mon, 7 Oct 2019 21:20:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B9E2D20867 for ; Mon, 7 Oct 2019 21:20:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fQg6xW+U" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729409AbfJGVUZ (ORCPT ); Mon, 7 Oct 2019 17:20:25 -0400 Received: from mail-pg1-f173.google.com ([209.85.215.173]:33256 "EHLO mail-pg1-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728702AbfJGVUY (ORCPT ); Mon, 7 Oct 2019 17:20:24 -0400 Received: by mail-pg1-f173.google.com with SMTP id i76so1819785pgc.0; Mon, 07 Oct 2019 14:20:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language:content-transfer-encoding; bh=sycFjW76TPrYh+EZFOry3N94dzhDeaSje8SkQ8MSXvA=; b=fQg6xW+UFVl4P5jrJBH5q5AbD5KcDxnKN1kXTZpWdgzKMqmmuTYG2xLAJDsaA3/w0x /zsYlRlbB/HYh6y5zOevSg0qAa7wdD6h5Q8WsM9tTdgt599iFljrwg/54zrfgNiwBVKR DTe4JzulD6AZoHnqjJJZqY7uUmWt3N+10ivfsbf74Iuyp+MlAkiRMMULp/7QFMs0eBwu GuROimN69l6vkT8EhSYpzSg2rgMFXfcHggNwpe8KwHz7aqmqBt+EFYle/0Sc8UtQRmzT Yh5rXs+KMKZo0L+LynbLdKQ7oR8XTdcIlOsIVFNGgRvK/Cp+broBsSgWlF20A7O96EbB OB/A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=sycFjW76TPrYh+EZFOry3N94dzhDeaSje8SkQ8MSXvA=; b=RLvL3Cbp+kd0CcYhMdzNj5VtgaxIMuG8tp+WzM3l56ivRkhsT2oAoYlNSafMLfXhJv RYg671VdIL/5gUohq84JcS0/65Z/+uvUVYcX2R8vEx8eoUAJWs/AswaWXuBoChdc6I+c TbchmTxjUerVGgkEB+4zzSk79esOMpRWlS59I5IVd9mlyol3BCt1AfgajlZ8pQ1bh0cp LkPMEh4AV0mUWzr6+tcgUL5GjRxMUcPiv+OmjATdyxUHA7JGNVAgT4oGf2rlp/STgdJz 0w29/ovYKwLC8dknyglvAz+0/K7Xreaylh7NIxN9hVh+B8jpCM5BpOnNqLP4P015qJ/E CcVw== X-Gm-Message-State: APjAAAUAtIb5d0egA7dmhJDXrqMYSq6GHLFjdcBkmA2aTHxXGEwOSG9M OnU59dyAwKObz7KFHZ5X3CQeaTPV X-Google-Smtp-Source: APXvYqyIN2WyX2O/LtktWbQBDxOmrCtq3FQCtQmqRN0tsPHmd49xQZm2L1P3TBbGfx6R85XTdNkOhw== X-Received: by 2002:a63:33c4:: with SMTP id z187mr10304868pgz.30.1570483223810; Mon, 07 Oct 2019 14:20:23 -0700 (PDT) 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 q76sm27325812pfc.86.2019.10.07.14.20.21 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 07 Oct 2019 14:20:22 -0700 (PDT) Subject: Re: Potential NULL pointer deference in net: sched To: Yizhuo Zhai , Jamal Hadi Salim , Cong Wang , Jiri Pirko , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Zhiyun Qian , Chengyu Song References: From: Eric Dumazet Message-ID: Date: Mon, 7 Oct 2019 14:20:21 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/7/19 2:08 PM, Yizhuo Zhai wrote: > Hi All: > > net/sched/sch_mq.c: > Inside function mq_dump_class(), mq_queue_get() could return NULL, > however, the return value of dev_queue is not checked and get used. > This could potentially be unsafe. > > Not really. mq_dump_class() is called by a layer that made sure the @cl argument was not complete garbage.