2025-09-15 14:03:55
Linux
PUBLISHED
In the Linux kernel, the following vulnerability has been resolved:
power: supply: bq25890: Fix external_power_changed race
bq25890_charger_external_power_changed() dereferences bq->charger,
which gets sets in bq25890_power_supply_init() like this:
bq->charger = devm_power_supply_register(bq->dev, &bq->desc, &psy_cfg);
As soon as devm_power_supply_register() has called device_add()
the external_power_changed callback can get called. So there is a window
where bq25890_charger_external_power_changed() may get called while
bq->charger has not been set yet leading to a NULL pointer dereference.
This race hits during boot sometimes on a Lenovo Yoga Book 1 yb1-x90f
when the cht_wcove_pwrsrc (extcon) power_supply is done with detecting
the connected charger-type which happens to exactly hit the small window:
BUG: kernel NULL pointer dereference, address: 0000000000000018