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: rel_imx_4.19.35_1.1.0~7165
X-Git-Url: https://git.somdevices.com/?a=commitdiff_plain;h=30805ece50683025ecf06b1d18d540e305550409;p=linux.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 ec083665f1fd..e0802d15ace0 100644
--- 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;