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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3E2B0C3DA7A for ; Fri, 6 Jan 2023 14:36:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235058AbjAFOgZ (ORCPT ); Fri, 6 Jan 2023 09:36:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41812 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233789AbjAFOgP (ORCPT ); Fri, 6 Jan 2023 09:36:15 -0500 Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6C93C67BF3; Fri, 6 Jan 2023 06:36:14 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 01D1326572; Fri, 6 Jan 2023 14:36:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1673015773; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=cyA+rzUmCJe634szsMWfvCeiahqN7Z90H5rR+wJZupE=; b=Rlvt4yQlGWdaRnydMv0xO4Pc5jNWfo7pbJleru4LDu3pTUbN2rEMMZHk5H4JEMctXNUVwB U2LDa58Aw8vclgcnTzN/Kl8I/6Plszo8jZKPcQFzsnIGM0JcPWhX4snEm94GVbArexv5PQ Rb9juinfir4DfI5Ge3ObL7GcV+hQLzU= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1673015773; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=cyA+rzUmCJe634szsMWfvCeiahqN7Z90H5rR+wJZupE=; b=UTEVgsSJgNEhZF0g/FA9vfUhhnswavGd1JDAcG2Ss2SiJK6HFckesDAqaLBa099tiFLDgE 6zCprhfL6wAuduCw== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id E7013139D5; Fri, 6 Jan 2023 14:36:12 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id izplONwxuGPLfQAAMHmgww (envelope-from ); Fri, 06 Jan 2023 14:36:12 +0000 Received: by quack3.suse.cz (Postfix, from userid 1000) id 64A1FA0742; Fri, 6 Jan 2023 15:36:12 +0100 (CET) Date: Fri, 6 Jan 2023 15:36:12 +0100 From: Jan Kara To: Baokun Li Cc: linux-ext4@vger.kernel.org, tytso@mit.edu, adilger.kernel@dilger.ca, jack@suse.cz, ritesh.list@gmail.com, linux-kernel@vger.kernel.org, yi.zhang@huawei.com, yukuai3@huawei.com, =?utf-8?B?THXDrXM=?= Henriques Subject: Re: [PATCH 2/2] ext4: update s_journal_inum if it changes after journal replay Message-ID: <20230106143612.nzif3jndh7p32nej@quack3> References: <20230106104706.2410740-1-libaokun1@huawei.com> <20230106104706.2410740-3-libaokun1@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20230106104706.2410740-3-libaokun1@huawei.com> Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Fri 06-01-23 18:47:06, Baokun Li wrote: > When mounting a crafted ext4 image, s_journal_inum may change after journal > replay, which is obviously unreasonable because we have successfully loaded > and replayed the journal through the old s_journal_inum. And the new > s_journal_inum bypasses some of the checks in ext4_get_journal(), which > may trigger a null pointer dereference problem. So if s_journal_inum > changes after the journal replay, we ignore the change, and rewrite the > current journal_inum to the superblock. > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=216541 > Reported-by: Luís Henriques > Signed-off-by: Baokun Li > --- > fs/ext4/super.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) Looks good. Feel free to add: Reviewed-by: Jan Kara Honza > > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > index 260c1b3e3ef2..3fe9dc19ff9c 100644 > --- a/fs/ext4/super.c > +++ b/fs/ext4/super.c > @@ -5953,8 +5953,11 @@ static int ext4_load_journal(struct super_block *sb, > if (!really_read_only && journal_devnum && > journal_devnum != le32_to_cpu(es->s_journal_dev)) { > es->s_journal_dev = cpu_to_le32(journal_devnum); > - > - /* Make sure we flush the recovery flag to disk. */ > + ext4_commit_super(sb); > + } > + if (!really_read_only && journal_inum && > + journal_inum != le32_to_cpu(es->s_journal_inum)) { > + es->s_journal_inum = cpu_to_le32(journal_inum); > ext4_commit_super(sb); > } > > -- > 2.31.1 > -- Jan Kara SUSE Labs, CR