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=-3.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 26914C43331 for ; Thu, 26 Mar 2020 14:53:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 02F8B2076A for ; Thu, 26 Mar 2020 14:53:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727793AbgCZOx1 (ORCPT ); Thu, 26 Mar 2020 10:53:27 -0400 Received: from outgoing-auth-1.mit.edu ([18.9.28.11]:59240 "EHLO outgoing.mit.edu" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726267AbgCZOx1 (ORCPT ); Thu, 26 Mar 2020 10:53:27 -0400 Received: from callcc.thunk.org (pool-72-93-95-157.bstnma.fios.verizon.net [72.93.95.157]) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 02QErBfW000898 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 26 Mar 2020 10:53:11 -0400 Received: by callcc.thunk.org (Postfix, from userid 15806) id 14444420EBA; Thu, 26 Mar 2020 10:53:11 -0400 (EDT) Date: Thu, 26 Mar 2020 10:53:11 -0400 From: "Theodore Y. Ts'o" To: Jan Kara Cc: Ritesh Harjani , linux-ext4@vger.kernel.org, adilger.kernel@dilger.ca, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH] ext4: Unregister sysfs path before destroying jbd2 journal Message-ID: <20200326145311.GR53396@mit.edu> References: <20200318061301.4320-1-riteshh@linux.ibm.com> <20200318091318.GJ22684@quack2.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200318091318.GJ22684@quack2.suse.cz> Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Wed, Mar 18, 2020 at 10:13:18AM +0100, Jan Kara wrote: > On Wed 18-03-20 11:43:01, Ritesh Harjani wrote: > > Call ext4_unregister_sysfs(), before destroying jbd2 journal, > > since below might cause, NULL pointer dereference issue. > > This got reported with LTP tests. > > > > ext4_put_super() cat /sys/fs/ext4/loop2/journal_task > > | ext4_attr_show(); > > ext4_jbd2_journal_destroy(); | > > | journal_task_show() > > | | > > | task_pid_vnr(NULL); > > sbi->s_journal = NULL; > > > > Signed-off-by: Ritesh Harjani > > Yeah, makes sence. Thanks for the patch! You can add: > > Reviewed-by: Jan Kara Applied, thanks. - Ted