This is a note to let you know that I've just added the patch titled media: i2c: tda1997: Fix possible use-after-free in tda1997x_remove() to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: media-i2c-tda1997-fix-possible-use-after-free-in-tda.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit ff4fbd66df6e918fdc8b24a86cdc6ba8b2c53b2b Author: Yang Yingliang <yangyingliang@xxxxxxxxxx> Date: Tue Apr 6 15:49:45 2021 +0200 media: i2c: tda1997: Fix possible use-after-free in tda1997x_remove() [ Upstream commit 7f820ab5d4eebfe2d970d32a76ae496a6c286f0f ] 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@xxxxxxxxxx> Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx> Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/media/i2c/tda1997x.c b/drivers/media/i2c/tda1997x.c index 5e68182001ec..e43d8327b810 100644 --- a/drivers/media/i2c/tda1997x.c +++ b/drivers/media/i2c/tda1997x.c @@ -2804,7 +2804,7 @@ static int tda1997x_remove(struct i2c_client *client) media_entity_cleanup(&sd->entity); v4l2_ctrl_handler_free(&state->hdl); regulator_bulk_disable(TDA1997X_NUM_SUPPLIES, state->supplies); - cancel_delayed_work(&state->delayed_work_enable_hpd); + cancel_delayed_work_sync(&state->delayed_work_enable_hpd); mutex_destroy(&state->page_lock); mutex_destroy(&state->lock);