power: supply: generic-adc-battery: fix possible use-after-free in gab_remove()

[ Upstream commit b6cfa007b3b229771d9588970adb4ab3e0487f49 ]

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: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/power/generic-adc-battery.c b/drivers/power/generic-adc-battery.c
index fedc5818fab7b74b96b5da2f81b77d4a992c6baf..86289f9da85ac10d181194aebec18119b26dfb43 100644 (file)
--- a/drivers/power/generic-adc-battery.c
+++ b/drivers/power/generic-adc-battery.c
@@ -379,7 +379,7 @@ static int gab_remove(struct platform_device *pdev)
        }
 
        kfree(adc_bat->psy_desc.properties);
-       cancel_delayed_work(&adc_bat->bat_work);
+       cancel_delayed_work_sync(&adc_bat->bat_work);
        return 0;
 }