From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755166AbdBPAe4 (ORCPT ); Wed, 15 Feb 2017 19:34:56 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:52248 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752311AbdBOWvO (ORCPT ); Wed, 15 Feb 2017 17:51:14 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Karel Zak" , "Jan Kara" , "Kent Overstreet" Date: Wed, 15 Feb 2017 22:41:34 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 044/126] isofs: Do not return EACCES for unknown filesystems In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.85-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Jan Kara commit a2ed0b391dd9c3ef1d64c7c3e370f4a5ffcd324a upstream. When isofs_mount() is called to mount a device read-write, it returns EACCES even before it checks that the device actually contains an isofs filesystem. This may confuse mount(8) which then tries to mount all subsequent filesystem types in read-only mode. Fix the problem by returning EACCES only once we verify that the device indeed contains an iso9660 filesystem. Fixes: 17b7f7cf58926844e1dd40f5eb5348d481deca6a Reported-by: Kent Overstreet Reported-by: Karel Zak Signed-off-by: Jan Kara Signed-off-by: Ben Hutchings --- fs/isofs/inode.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) --- a/fs/isofs/inode.c +++ b/fs/isofs/inode.c @@ -717,6 +717,11 @@ static int isofs_fill_super(struct super pri_bh = NULL; root_found: + /* We don't support read-write mounts */ + if (!(s->s_flags & MS_RDONLY)) { + error = -EACCES; + goto out_freebh; + } if (joliet_level && (pri == NULL || !opt.rock)) { /* This is the case of Joliet with the norock mount flag. @@ -1527,9 +1532,6 @@ struct inode *__isofs_iget(struct super_ static struct dentry *isofs_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) { - /* We don't support read-write mounts */ - if (!(flags & MS_RDONLY)) - return ERR_PTR(-EACCES); return mount_bdev(fs_type, flags, dev_name, data, isofs_fill_super); }