From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752314AbeDIOZW (ORCPT ); Mon, 9 Apr 2018 10:25:22 -0400 Received: from mx2.suse.de ([195.135.220.15]:49870 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751862AbeDIOZU (ORCPT ); Mon, 9 Apr 2018 10:25:20 -0400 Date: Mon, 9 Apr 2018 16:25:17 +0200 From: Jan Kara To: Jeff Mahoney Cc: Andrew Morton , Randy Dunlap , LKML , reiserfs-devel@vger.kernel.org, Alexander Viro , Jan Kara , Frederic Weisbecker , Artem Bityutskiy , syzkaller-bugs@googlegroups.com, syzbot+6bd77b88c1977c03f584@syzkaller.appspotmail.com Subject: Re: [PATCH?] reiserfs: prevent panic: don't allow %-char in journal dev. name Message-ID: <20180409142517.qrorcyng6puk4qed@quack2.suse.cz> References: <20180404184517.9f2b91b856a56f71464f5f7f@linux-foundation.org> <5e9ea36a-6a6a-921c-81b3-bc623a9e125a@suse.com> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="3boyrbnt6apoxgr5" Content-Disposition: inline In-Reply-To: <5e9ea36a-6a6a-921c-81b3-bc623a9e125a@suse.com> User-Agent: NeoMutt/20170421 (1.8.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --3boyrbnt6apoxgr5 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed 04-04-18 21:48:53, Jeff Mahoney wrote: > On 4/4/18 9:45 PM, Andrew Morton wrote: > > On Wed, 4 Apr 2018 18:25:16 -0700 Randy Dunlap wrote: > > > >> From: Randy Dunlap > >> > >> If the reiserfs mount option's journal name contains a '%' character, > >> it can lead to a WARN_ONCE() in lib/vsprintf.c::format_decode(), > >> saying: "Please remove unsupported %/ in format string." > >> That's OK until panic_on_warn is set, at which point it's dead, Jim. > >> > >> To placate this situation, check the journal name string for a '%' > >> character and return an error if one is found. Also print a warning > >> (one that won't panic the kernel) about the invalid journal name (e.g.): > >> > >> reiserfs: journal device name is invalid: %/file0 > >> > >> (In this example, the caller app specified the journal device name as > >> "%/file0".) > >> > > > > Well, that is a valid filename and we should support it... > > > > Isn't the bug in journal_init_dev()? > > Yep. That's exactly it. > > Acked-by: Jeff Mahoney Thanks. I've picked up the patch from Andrew, added his Signed-off-by (OK, Andrew?), wrote a proper changelog and pushed it to my tree. The result is attached. Honza -- Jan Kara SUSE Labs, CR --3boyrbnt6apoxgr5 Content-Type: text/x-patch; charset=us-ascii Content-Disposition: attachment; filename="0001-reiserfs-Fix-warning-for-non-existing-journal-device.patch" >>From 121724c8bb9d5c07ee12718520f6f99b0da0a275 Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Mon, 9 Apr 2018 16:17:44 +0200 Subject: [PATCH] reiserfs: Fix warning for non-existing journal devices When a journal device specified as part of mount options does not exist, reiserfs issues a warking like: reiserfs_warning(super, "journal_init_dev: Cannot open '%s': %i", jdev_name, result); Now this misses a parameter 'id' of reiserfs_warning() which comes second. As such, the format string is interpreted as an ID and jdev_name as a format string resulting in funny issues. Fix the problem by adding missing 'id' argument. Reported-by: Randy Dunlap Signed-off-by: Andrew Morton Acked-by: Jeff Mahoney Signed-off-by: Jan Kara --- fs/reiserfs/journal.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/reiserfs/journal.c b/fs/reiserfs/journal.c index 70057359fbaf..23148c3ed675 100644 --- a/fs/reiserfs/journal.c +++ b/fs/reiserfs/journal.c @@ -2643,7 +2643,7 @@ static int journal_init_dev(struct super_block *super, if (IS_ERR(journal->j_dev_bd)) { result = PTR_ERR(journal->j_dev_bd); journal->j_dev_bd = NULL; - reiserfs_warning(super, + reiserfs_warning(super, "sh-457", "journal_init_dev: Cannot open '%s': %i", jdev_name, result); return result; -- 2.13.6 --3boyrbnt6apoxgr5--