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=-11.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 2919BC433E6 for ; Fri, 28 Aug 2020 09:21:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 044E6208CA for ; Fri, 28 Aug 2020 09:21:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728798AbgH1JVX (ORCPT ); Fri, 28 Aug 2020 05:21:23 -0400 Received: from mx2.suse.de ([195.135.220.15]:44294 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726010AbgH1JVV (ORCPT ); Fri, 28 Aug 2020 05:21:21 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id EA441B742; Fri, 28 Aug 2020 09:21:52 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 704C11E12C0; Fri, 28 Aug 2020 11:21:19 +0200 (CEST) Date: Fri, 28 Aug 2020 11:21:19 +0200 From: Jan Kara To: Dinghao Liu Cc: kjlu@umn.edu, Theodore Ts'o , Andreas Dilger , linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] ext4: Fix memleak in add_new_gdb Message-ID: <20200828092119.GE7072@quack2.suse.cz> References: <20200827062843.10188-1-dinghao.liu@zju.edu.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200827062843.10188-1-dinghao.liu@zju.edu.cn> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 27-08-20 14:28:43, Dinghao Liu wrote: > When ext4_journal_get_write_access() fails, we should release > n_group_desc, iloc.bh, dind and gdb_bh to prevent memleak. > It's the same when ext4_handle_dirty_super() fails, but we > don't need to release dind here because it has been released > before. > > Signed-off-by: Dinghao Liu Thanks for the patch! Some comments below: > diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c > index a50b51270ea9..efc0a022ca8e 100644 > --- a/fs/ext4/resize.c > +++ b/fs/ext4/resize.c > @@ -843,8 +843,10 @@ static int add_new_gdb(handle_t *handle, struct inode *inode, > > BUFFER_TRACE(dind, "get_write_access"); > err = ext4_journal_get_write_access(handle, dind); > - if (unlikely(err)) > + if (unlikely(err)) { > ext4_std_error(sb, err); > + goto errout; > + } This hunk looks good. > @@ -899,13 +901,17 @@ static int add_new_gdb(handle_t *handle, struct inode *inode, > > le16_add_cpu(&es->s_reserved_gdt_blocks, -1); > err = ext4_handle_dirty_super(handle, sb); > - if (err) > + if (err) { > ext4_std_error(sb, err); > + goto errsuper; > + } > + > return err; > errout: > + brelse(dind); > +errsuper: But this is definitely wrong. Look, n_group_desc and gdb_bh are already referenced from the superblock so you cannot free them, iloc.bh has been released in ext4_mark_iloc_dirty(). Honza -- Jan Kara SUSE Labs, CR