2023-03-11 17:47:22

by Zheng Wang

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Subject: [PATCH v2] power: supply: da9150: Fix use after free bug in da9150_charger_remove due to race condition

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 da9150_charger_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 <[email protected]>
---
v2:
- fix wrong description in commit message and mov cancel_work_sync
after usb_unregister_notifier suggested by Sebastian Reichel
---
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..a87aeaea38e1 100644
--- a/drivers/power/supply/da9150-charger.c
+++ b/drivers/power/supply/da9150-charger.c
@@ -657,6 +657,7 @@ static int da9150_charger_remove(struct platform_device *pdev)

if (!IS_ERR_OR_NULL(charger->usb_phy))
usb_unregister_notifier(charger->usb_phy, &charger->otg_nb);
+ cancel_work_sync(&charger->otg_work);

power_supply_unregister(charger->battery);
power_supply_unregister(charger->usb);
--
2.25.1