From 2c9541720c66899adf6f3600984cf3ef151295ad Mon Sep 17 00:00:00 2001
From: Yang Yingliang <yangyingliang@huawei.com>
Date: Tue, 6 Apr 2021 15:48:12 +0200
Subject: [PATCH] media: i2c: adv7511-v4l2: fix possible use-after-free in adv7511_remove()
Git-commit: 2c9541720c66899adf6f3600984cf3ef151295ad
Patch-mainline: v5.13-rc1
References: git-fixes

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>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/media/i2c/adv7511-v4l2.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/media/i2c/adv7511-v4l2.c
+++ b/drivers/media/i2c/adv7511-v4l2.c
@@ -1965,7 +1965,7 @@ static int adv7511_remove(struct i2c_cli
 
 	adv7511_set_isr(sd, false);
 	adv7511_init_setup(sd);
-	cancel_delayed_work(&state->edid_handler);
+	cancel_delayed_work_sync(&state->edid_handler);
 	i2c_unregister_device(state->i2c_edid);
 	if (state->i2c_cec)
 		i2c_unregister_device(state->i2c_cec);