From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Mon, 12 Nov 2018 15:42:14 +0000 (-0700)
Subject: loop: Fix double mutex_unlock(&loop_ctl_mutex) in loop_control_ioctl()
X-Git-Tag: v4.14.95~5
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d2762edcb6af99fc9322bab0b1d4e71a427760e8;p=platform%2Fkernel%2Flinux-exynos.git

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 0b8b274eb682..11da9707e1ce 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1965,12 +1965,10 @@ 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;