From: Hans Verkuil hverkuil-cisco@xs4all.nl
commit 288eceb0858323d66bff03cf386630a797b248ad upstream.
For some inexplicable reason I decided to call flush_scheduled_work() instead of cancel_delayed_work_sync(). The problem with that is that flush_scheduled_work() waits for *all* queued scheduled work to be completed instead of just the work itself.
This can cause a deadlock if a CEC driver also schedules work that takes the same lock. See the comments for flush_scheduled_work() in linux/workqueue.h.
This is exactly what has been observed a few times.
This patch simply replaces flush_scheduled_work() by cancel_delayed_work_sync().
Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl Cc: stable@vger.kernel.org # for v5.8 and up Signed-off-by: Mauro Carvalho Chehab mchehab+huawei@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/media/cec/core/cec-adap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/media/cec/core/cec-adap.c +++ b/drivers/media/cec/core/cec-adap.c @@ -1199,7 +1199,7 @@ void cec_received_msg_ts(struct cec_adap /* Cancel the pending timeout work */ if (!cancel_delayed_work(&data->work)) { mutex_unlock(&adap->lock); - flush_scheduled_work(); + cancel_delayed_work_sync(&data->work); mutex_lock(&adap->lock); } /*