loop: Fix double mutex_unlock(&loop_ctl_mutex) in loop_control_ioctl()

commit 628bd85947091830a8c4872adfd5ed1d515a9cf2 upstream.

Commit 0a42e99b58a20883 ("loop: Get rid of loop_index_mutex") forgot to
remove mutex_unlock(&loop_ctl_mutex) from loop_control_ioctl() when
replacing loop_index_mutex with loop_ctl_mutex.

Fixes: 0a42e99b58a20883 ("loop: Get rid of loop_index_mutex")
Reported-by: syzbot <syzbot+c0138741c2290fc5e63f@syzkaller.appspotmail.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index ec083665f1fd9cf590ebc6f261500217369df8f9..e0802d15ace0ebaf524bfff020a6970a36a4a271 100644 (file)
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -2075,12 +2075,10 @@ static long loop_control_ioctl(struct file *file, unsigned int cmd,
                        break;
                if (lo->lo_state != Lo_unbound) {
                        ret = -EBUSY;
-                       mutex_unlock(&loop_ctl_mutex);
                        break;
                }
                if (atomic_read(&lo->lo_refcnt) > 0) {
                        ret = -EBUSY;
-                       mutex_unlock(&loop_ctl_mutex);
                        break;
                }
                lo->lo_disk->private_data = NULL;