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/supply/generic-adc-battery.c b/drivers/power/supply/generic-adc-battery.c
index bc462d1ec9630de42080e4e5be428252e36b2e8d..97b0e873e87d2e0aea2b787a4cd8daeae6de14cb 100644 (file)
--- a/drivers/power/supply/generic-adc-battery.c
+++ b/drivers/power/supply/generic-adc-battery.c
@@ -382,7 +382,7 @@ 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;
 }