[PATCH] power: supply: da9150: Fix use after free bug in da9150_charger_remove due to race condition

[Zheng Wang <zyytlz.wz@163.com>]

In da9150_charger_probe, &charger->otg_work is bound with
da9150_charger_otg_work. da9150_charger_otg_ncb may be
called to start the work.

If we remove the module which will call da9150_charger_remove
 to make cleanup, there may be a unfinished work. The possible
  sequence is as follows:

Fix it by canceling the work before cleanup in the mtk_jpeg_remove

CPU0                  CPUc1

                    |da9150_charger_otg_work
da9150_charger_remove      |
power_supply_unregister  |
device_unregister   |
power_supply_dev_release|
kfree(psy)          |
                    |
                    | 	power_supply_changed(charger->usb);
                    |   //use
Fixes: c1a281e34dae ("power: Add support for DA9150 Charger")
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
---
 drivers/power/supply/da9150-charger.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/power/supply/da9150-charger.c b/drivers/power/supply/da9150-charger.c
index 14da5c595dd9..41b68f2f6ed8 100644
--- a/drivers/power/supply/da9150-charger.c
+++ b/drivers/power/supply/da9150-charger.c
@@ -642,6 +642,7 @@ static int da9150_charger_remove(struct platform_device *pdev)
 	struct da9150_charger *charger = platform_get_drvdata(pdev);
 	int irq;
 
+	cancel_work_sync(&charger->otg_work);
 	/* Make sure IRQs are released before unregistering power supplies */
 	irq = platform_get_irq_byname(pdev, "CHG_VBUS");
 	free_irq(irq, charger);
-- 
2.25.1