From 7f1a57fdd6cb6e7be2ed31878a34655df38e1861 Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski Date: Tue, 19 May 2015 16:13:02 +0900 Subject: power_supply: Fix possible NULL pointer dereference on early uevent Don't call the power_supply_changed() from power_supply_register() when parent is still probing because it may lead to accessing parent too early. In bq27x00_battery this caused NULL pointer exception because uevent of power_supply_changed called back the the get_property() method provided by the driver. The get_property() method accessed pointer which should be returned by power_supply_register(). Starting from bq27x00_battery_probe(): di->bat = power_supply_register() power_supply_changed() kobject_uevent() power_supply_uevent() power_supply_show_property() power_supply_get_property() bq27x00_battery_get_property() dereference of di->bat which is NULL here The dereference of di->bat (value returned by power_supply_register()) is the currently visible problem. However calling back the methods provided by driver before ending the probe may lead to accessing other driver-related data which is not yet initialized. The call to power_supply_changed() is postponed till probing ends - mutex of parent device is released. Reported-by: H. Nikolaus Schaller Signed-off-by: Krzysztof Kozlowski Fixes: 297d716f6260 ("power_supply: Change ownership from driver to core") Tested-By: Dr. H. Nikolaus Schaller Signed-off-by: Sebastian Reichel --- include/linux/power_supply.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h index 75a1dd8dc56e..a80f1fd01ddb 100644 --- a/include/linux/power_supply.h +++ b/include/linux/power_supply.h @@ -237,6 +237,7 @@ struct power_supply { /* private */ struct device dev; struct work_struct changed_work; + struct delayed_work deferred_register_work; spinlock_t changed_lock; bool changed; atomic_t use_cnt; -- cgit v1.2.3