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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 B1D0EC43470 for ; Thu, 15 Apr 2021 14:49:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 96E61613C7 for ; Thu, 15 Apr 2021 14:49:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233662AbhDOOtp (ORCPT ); Thu, 15 Apr 2021 10:49:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42902 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233728AbhDOOte (ORCPT ); Thu, 15 Apr 2021 10:49:34 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C1B9AC061574; Thu, 15 Apr 2021 07:49:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=Z7+Tu/cOwOD4zUSujDMlZ1cKk6U8IueYF+2Nrcr7Rpk=; b=R5h6S1tyNmZbHxJvdQgMubPVSB DTeZTGp1jMPNCG0srQBvRf+z0qDzeG4yVZj/KEy6gqRkwlPpujWI6LRwf2My5VNizUenOYZ9Mu9KG 6FQDSkVfGGPlZN5wGXoj40L8fG+exL/JDAoCxDYwhsB2JIcql7FSgO766mvQVk4dzW5TD/u7OzRH8 c83AR1fS2V70km5x4DZTmO04ZLm94DTw9sI/cI1h0Zve2oMbKR1xWKIzYn7Q5D+B6dHtdBqjW8rhg RAPUJSwr8vHM6AeCu3bSjrzc4yrSio1uZk3EqegbTrSqL9vR47nMz87XwyVqlWxVyYzzLj7W0D21J QM6z7T0Q==; Received: from hch by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lX3ID-008gt0-EE; Thu, 15 Apr 2021 14:48:36 +0000 Date: Thu, 15 Apr 2021 15:48:29 +0100 From: Christoph Hellwig To: Zhang Yi Cc: linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, tytso@mit.edu, adilger.kernel@dilger.ca, jack@suse.cz, yukuai3@huawei.com Subject: Re: [RFC PATCH v2 5/7] ext4: use RCU to protect accessing superblock in blkdev_releasepage() Message-ID: <20210415144829.GC2069063@infradead.org> References: <20210414134737.2366971-1-yi.zhang@huawei.com> <20210414134737.2366971-6-yi.zhang@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210414134737.2366971-6-yi.zhang@huawei.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, Apr 14, 2021 at 09:47:35PM +0800, Zhang Yi wrote: > In blkdev_releasepage() we access the superblock structure directly, it > could be raced by umount filesystem on destroy superblock in put_super(), > and end up triggering a use after free issue. The subject is wrong, this does not change ext4 code.