From 68ae256945d2abe9036a7b68af4cc65aff79d5b7 Mon Sep 17 00:00:00 2001
From: Yang Yingliang <yangyingliang@huawei.com>
Date: Wed, 7 Apr 2021 17:19:03 +0800
Subject: [PATCH] power: supply: s3c_adc_battery: fix possible use-after-free in s3c_adc_bat_remove()
Git-commit: 68ae256945d2abe9036a7b68af4cc65aff79d5b7
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>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/power/supply/s3c_adc_battery.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/power/supply/s3c_adc_battery.c
+++ b/drivers/power/supply/s3c_adc_battery.c
@@ -392,7 +392,7 @@ static int s3c_adc_bat_remove(struct pla
 		gpio_free(pdata->gpio_charge_finished);
 	}
 
-	cancel_delayed_work(&bat_work);
+	cancel_delayed_work_sync(&bat_work);
 
 	if (pdata->exit)
 		pdata->exit();