media: i2c: adv7842: fix possible use-after-free in adv7842_remove()

This driver's remove path calls cancel_delayed_work(). However, that
function does not wait until the work function finishes. This means
that the callback function may still be running after the driver's
remove function has finished, which would result in a use-after-free.

Fix by calling cancel_delayed_work_sync(), which ensures that
the work is properly cancelled, no longer running, and unable
to re-schedule itself.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
This commit is contained in:
Yang Yingliang 2021-04-06 15:50:53 +02:00 committed by Mauro Carvalho Chehab
parent 7f820ab5d4
commit 4a15275b6a

View File

@ -3573,7 +3573,7 @@ static int adv7842_remove(struct i2c_client *client)
struct adv7842_state *state = to_state(sd);
adv7842_irq_enable(sd, false);
cancel_delayed_work(&state->delayed_work_enable_hotplug);
cancel_delayed_work_sync(&state->delayed_work_enable_hotplug);
v4l2_device_unregister_subdev(sd);
media_entity_cleanup(&sd->entity);
adv7842_unregister_clients(sd);