From 7f820ab5d4eebfe2d970d32a76ae496a6c286f0f Mon Sep 17 00:00:00 2001
From: Yang Yingliang <yangyingliang@huawei.com>
Date: Tue, 6 Apr 2021 15:49:45 +0200
Subject: [PATCH] media: i2c: tda1997: Fix possible use-after-free in tda1997x_remove()
Git-commit: 7f820ab5d4eebfe2d970d32a76ae496a6c286f0f
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/tda1997x.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/i2c/tda1997x.c b/drivers/media/i2c/tda1997x.c
index a09bf0a39d05..89bb7e6dc7a4 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);
 
-- 
2.26.2