dm delay: fix a crash when invalid device is specified
When the target line contains an invalid device, delay_ctr() will call
delay_dtr() with NULL workqueue. Attempting to destroy the NULL
workqueue causes a crash.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm-delay.c b/drivers/md/dm-delay.c
index fddffe2..f496213 100644
--- a/drivers/md/dm-delay.c
+++ b/drivers/md/dm-delay.c
@@ -121,7 +121,8 @@ static void delay_dtr(struct dm_target *ti)
{
struct delay_c *dc = ti->private;
- destroy_workqueue(dc->kdelayd_wq);
+ if (dc->kdelayd_wq)
+ destroy_workqueue(dc->kdelayd_wq);
if (dc->read.dev)
dm_put_device(ti, dc->read.dev);
