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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21456C433EF for ; Mon, 15 Nov 2021 06:14:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EB56463212 for ; Mon, 15 Nov 2021 06:14:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229935AbhKOGRe (ORCPT ); Mon, 15 Nov 2021 01:17:34 -0500 Received: from szxga01-in.huawei.com ([45.249.212.187]:14741 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229587AbhKOGRV (ORCPT ); Mon, 15 Nov 2021 01:17:21 -0500 Received: from dggemv703-chm.china.huawei.com (unknown [172.30.72.53]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4HszNY5f9kzZd4n; Mon, 15 Nov 2021 14:11:41 +0800 (CST) Received: from dggpemm500006.china.huawei.com (7.185.36.236) by dggemv703-chm.china.huawei.com (10.3.19.46) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Mon, 15 Nov 2021 14:13:56 +0800 Received: from [10.174.178.55] (10.174.178.55) by dggpemm500006.china.huawei.com (7.185.36.236) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Mon, 15 Nov 2021 14:13:56 +0800 Subject: Re: [PATCH 1/2] pipe: fix potential use-after-free in pipe_read() To: Matthew Wilcox CC: Alexander Viro , David Howells , , References: <20211115035721.1909-1-thunder.leizhen@huawei.com> <20211115035721.1909-2-thunder.leizhen@huawei.com> From: "Leizhen (ThunderTown)" Message-ID: Date: Mon, 15 Nov 2021 14:13:44 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.178.55] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggpemm500006.china.huawei.com (7.185.36.236) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 2021/11/15 12:25, Matthew Wilcox wrote: > On Mon, Nov 15, 2021 at 11:57:20AM +0800, Zhen Lei wrote: >> if (!buf->len) { >> + unsigned int __maybe_unused flags = buf->flags; > > Why __maybe_unused? It's used only if "#ifdef CONFIG_WATCH_QUEUE". Otherwise, a warning will be reported. > . >