isofs: Do not return EACCES for unknown filesystems
[ Upstream commit a2ed0b391dd9c3ef1d64c7c3e370f4a5ffcd324a ]
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.
CC: stable@vger.kernel.org
Fixes: 17b7f7cf58926844e1dd40f5eb5348d481deca6a
Reported-by: Kent Overstreet <kent.overstreet@gmail.com>
Reported-by: Karel Zak <kzak@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c
index d67a16f..350f67f 100644
--- a/fs/isofs/inode.c
+++ b/fs/isofs/inode.c
@@ -690,6 +690,11 @@
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.
@@ -1503,9 +1508,6 @@
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);
}