[PATCH 4.9 088/141] gfs2_meta: ->mount() can get NULL dev_name

Greg Kroah-Hartman
2018-11-11T22:34:40Z

From: Al Viro <viro@zeniv.linux.org.uk>

commit 3df629d873f8683af6f0d34dfc743f637966d483 upstream.

get in sync with mount_bdev() handling of the same

Reported-by: syzbot+c54f8e94e6bba03b04e9@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/gfs2/ops_fstype.c | 3 +++
1 file changed, 3 insertions(+)

--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -1355,6 +1355,9 @@ static struct dentry *gfs2_mount_meta(st
struct path path;
int error;

+ if (!dev_name || !*dev_name)
+ return ERR_PTR(-EINVAL);
+
error = kern_path(dev_name, LOOKUP_FOLLOW, &path);
if (error) {
pr_warn("path_lookup on %s returned error %d\n",