This is a note to let you know that I've just added the patch titled
power: supply: sc27xx: Fix external_power_changed race
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
power-supply-sc27xx-fix-external_power_changed-race.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 4138207a3dd44814181be3f6402274552cc42043
Author: Hans de Goede <hdegoede@xxxxxxxxxx>
Date: Sat Apr 15 18:07:32 2023 +0200
power: supply: sc27xx: Fix external_power_changed race
[ Upstream commit 4d5c129d6c8993fe96e9ae712141eedcb9ca68c2 ]
sc27xx_fgu_external_power_changed() dereferences data->battery,
which gets sets in ab8500_btemp_probe() like this:
data->battery = devm_power_supply_register(dev, &sc27xx_fgu_desc,
&fgu_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 sc27xx_fgu_external_power_changed() may get called while
data->battery has not been set yet leading to a NULL pointer dereference.
Fixing this is easy. The external_power_changed callback gets passed
the power_supply which will eventually get stored in data->battery,
so sc27xx_fgu_external_power_changed() can simply directly use
the passed in psy argument which is always valid.
After this change sc27xx_fgu_external_power_changed() is reduced to just
"power_supply_changed(psy);" and it has the same prototype. While at it
simply replace it with making the external_power_changed callback
directly point to power_supply_changed.
Cc: Orson Zhai <orsonzhai@xxxxxxxxx>
Cc: Chunyan Zhang <zhang.lyra@xxxxxxxxx>
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/power/supply/sc27xx_fuel_gauge.c b/drivers/power/supply/sc27xx_fuel_gauge.c
index 1ae8374e1cebe..3bf4b263950d7 100644
--- a/drivers/power/supply/sc27xx_fuel_gauge.c
+++ b/drivers/power/supply/sc27xx_fuel_gauge.c
@@ -733,13 +733,6 @@ static int sc27xx_fgu_set_property(struct power_supply *psy,
return ret;
}
-static void sc27xx_fgu_external_power_changed(struct power_supply *psy)
-{
- struct sc27xx_fgu_data *data = power_supply_get_drvdata(psy);
-
- power_supply_changed(data->battery);
-}
-
static int sc27xx_fgu_property_is_writeable(struct power_supply *psy,
enum power_supply_property psp)
{
@@ -774,7 +767,7 @@ static const struct power_supply_desc sc27xx_fgu_desc = {
.num_properties = ARRAY_SIZE(sc27xx_fgu_props),
.get_property = sc27xx_fgu_get_property,
.set_property = sc27xx_fgu_set_property,
- .external_power_changed = sc27xx_fgu_external_power_changed,
+ .external_power_changed = power_supply_changed,
.property_is_writeable = sc27xx_fgu_property_is_writeable,
.no_thermal = true,
};
