Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966327AbcJZM3N (ORCPT ); Wed, 26 Oct 2016 08:29:13 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:55434 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S941783AbcJZM3E (ORCPT ); Wed, 26 Oct 2016 08:29:04 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kent Overstreet , Karel Zak , Jan Kara Subject: [PATCH 4.8 114/140] isofs: Do not return EACCES for unknown filesystems Date: Wed, 26 Oct 2016 14:22:54 +0200 Message-Id: <20161026122225.254557966@linuxfoundation.org> X-Mailer: git-send-email 2.10.1 In-Reply-To: <20161026122220.384323763@linuxfoundation.org> References: <20161026122220.384323763@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1629 Lines: 51 4.8-stable 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: Greg Kroah-Hartman --- fs/isofs/inode.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) --- a/fs/isofs/inode.c +++ b/fs/isofs/inode.c @@ -687,6 +687,11 @@ 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. @@ -1501,9 +1506,6 @@ 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); }