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=-8.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 70950C1B0D8 for ; Wed, 9 Dec 2020 19:39:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1EA9623C92 for ; Wed, 9 Dec 2020 19:39:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730559AbgLITjU (ORCPT ); Wed, 9 Dec 2020 14:39:20 -0500 Received: from outgoing-auth-1.mit.edu ([18.9.28.11]:55135 "EHLO outgoing.mit.edu" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726794AbgLITaO (ORCPT ); Wed, 9 Dec 2020 14:30:14 -0500 Received: from callcc.thunk.org (pool-72-74-133-215.bstnma.fios.verizon.net [72.74.133.215]) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 0B9JTHYQ011572 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 9 Dec 2020 14:29:17 -0500 Received: by callcc.thunk.org (Postfix, from userid 15806) id 11915420136; Wed, 9 Dec 2020 14:29:17 -0500 (EST) Date: Wed, 9 Dec 2020 14:29:16 -0500 From: "Theodore Y. Ts'o" To: Chunguang Xu Cc: adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org Subject: Re: [PATCH RESEND 8/8] ext4: fix a memory leak of ext4_free_data Message-ID: <20201209192916.GN52960@mit.edu> References: <1604764698-4269-1-git-send-email-brookxu@tencent.com> <1604764698-4269-8-git-send-email-brookxu@tencent.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1604764698-4269-8-git-send-email-brookxu@tencent.com> Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Sat, Nov 07, 2020 at 11:58:18PM +0800, Chunguang Xu wrote: > From: Chunguang Xu > > When freeing metadata, we will create an ext4_free_data and > insert it into the pending free list. After the current > transaction is committed, the object will be freed. > > ext4_mb_free_metadata() will check whether the area to be > freed overlaps with the pending free list. If true, return > directly. At this time, ext4_free_data is leaked. Fortunately, > the probability of this problem is relatively small, maybe we > should fix this problem. > > Signed-off-by: Chunguang Xu Thanks, applied. I added an explanatory note that the leak would only happen when the file system is corrupted (a block claimed by more than one inode, with those inodes deleted within a single jbd2 transaction). - Ted