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=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 8B500C433FF for ; Mon, 29 Jul 2019 07:32:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5A56D216C8 for ; Mon, 29 Jul 2019 07:32:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bNjt42sb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726825AbfG2HcB (ORCPT ); Mon, 29 Jul 2019 03:32:01 -0400 Received: from mail-pl1-f193.google.com ([209.85.214.193]:37538 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726432AbfG2HcB (ORCPT ); Mon, 29 Jul 2019 03:32:01 -0400 Received: by mail-pl1-f193.google.com with SMTP id b3so27179440plr.4; Mon, 29 Jul 2019 00:32:00 -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=kchq7srFNNnQej0FuA0OClC0TaerJgYlzJ7LEi/VOUo=; b=bNjt42sboPYQB7y//DMTQDhTsSpnpt0//n63Gt7u2QeVZmOjHih58FEfRcxITnl7sd gscWwkd3Fg7xDMMZWAdB/yzW69PKf1fFp8eFNemclvm6+9gssvR2e3VRjafYw9coCOMi TjXjwovVU0EbyDimR5uRpYUB2Gl2hbOJfH5bCojm/lrVJhNlqg2KIkQZnUrgf4hlMKzS KWnOlWLBOB+yqDH3AFBfQMa1xzRqne5LiGhX2Vjw9jEWVxt+P6WfnpzCNt16i6d1FGe8 TOO83BcpFaiZDKJk83BBcmnAugUp+7LEeP4P5nhUQlM5J6ngehRfzNyc3pGlaKA49PmN tb2w== 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=kchq7srFNNnQej0FuA0OClC0TaerJgYlzJ7LEi/VOUo=; b=A4n/dlccl4Hg6vGSPWU7sII5OTXTdB+9wxfU6ypbw+oEC6opCaC2fahwQ+k9cHHb0v kaAhJH8mWhJAkmh9ea9rpWSSIenrQJUA+JKrUHGqOv0LjrQTJCz9QcQqyfqqiKwyTyO7 3zXnQ5vLAYlFvk1faxJ/5Vw8R0wnwTuiZFgm+bIYYTFMlrOb/yhSuihViIL4N1+og83o T3OLaqDXzZEGzG+pTauioJ72Ta2rFVJHTNawi6/JYHwUs52x8bUqi8KQwwJ+Ax8NGQgn BCvVIU/uJ9XzZFoWDibLpyWnBVHJyR6wlFJOzxaIdqoaTLv7JcKoJDadgVl24JjXDB+D Jf2Q== X-Gm-Message-State: APjAAAUVTLjewypKo0j90zEcOiYlAAuA4U439pMXx5ltVCJU7RjqH4GZ KRbDXZYuyc4xJ2JliFt/XlQM8oIy X-Google-Smtp-Source: APXvYqzksUM4T9kWfQkETZnrTNQlrjPAcYkIwFmRNDP0cDAYvvNt0zVFR9kJwPGQ8EtRj1kb+cJtjg== X-Received: by 2002:a17:902:da4:: with SMTP id 33mr99311122plv.209.1564385520477; Mon, 29 Jul 2019 00:32:00 -0700 (PDT) Received: from ?IPv6:2402:f000:4:72:808::177e? ([2402:f000:4:72:808::177e]) by smtp.gmail.com with ESMTPSA id u134sm59112458pfc.19.2019.07.29.00.31.58 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 29 Jul 2019 00:32:00 -0700 (PDT) Subject: Re: [PATCH] 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: <20190729022157.18090-1-baijiaju1990@gmail.com> <20190729065653.GA2211@nanopsycho> From: Jia-Ju Bai Message-ID: <4752bf67-7a0c-7bc9-3d54-f18361085ba2@gmail.com> Date: Mon, 29 Jul 2019 15:32:00 +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: <20190729065653.GA2211@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 14:56, Jiri Pirko wrote: > Mon, Jul 29, 2019 at 04:21:57AM 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. >> >> Signed-off-by: Jia-Ju Bai > Fixes tag, please? Sorry, I do not know what "fixes tag" means... I just find a possible bug and fix it in this patch. Best wishes, Jia-Ju Bai