media: adv7604: fix possible use-after-free in adv76xx_remove()

[ Upstream commit fa56f5f1fe ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Yang Yingliang
2021-04-06 15:42:46 +02:00
committed by Chris
parent 08de05db92
commit d648031a88

View File

@@ -3541,7 +3541,7 @@ static int adv76xx_remove(struct i2c_client *client)
io_write(sd, 0x6e, 0);
io_write(sd, 0x73, 0);
cancel_delayed_work(&state->delayed_work_enable_hotplug);
cancel_delayed_work_sync(&state->delayed_work_enable_hotplug);
v4l2_async_unregister_subdev(sd);
media_entity_cleanup(&sd->entity);
adv76xx_unregister_clients(to_state(sd));