This is a note to let you know that I've just added the patch titled
power: supply: ab8500: Fix external_power_changed race
to the 4.19-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-ab8500-fix-external_power_changed-race.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3b6a28dcd58f92cf4ad3903346b55f4cfb36c1d9
Author: Hans de Goede <hdegoede@xxxxxxxxxx>
Date: Sat Apr 15 18:07:29 2023 +0200
power: supply: ab8500: Fix external_power_changed race
[ Upstream commit a5299ce4e96f3e8930e9c051b28d8093ada87b08 ]
ab8500_btemp_external_power_changed() dereferences di->btemp_psy,
which gets sets in ab8500_btemp_probe() like this:
di->btemp_psy = devm_power_supply_register(dev, &ab8500_btemp_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 ab8500_btemp_external_power_changed() may get called while
di->btemp_psy 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 di->btemp_psy,
so ab8500_btemp_external_power_changed() can simply directly use
the passed in psy argument which is always valid.
And the same applies to ab8500_fg_external_power_changed().
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/power/supply/ab8500_btemp.c b/drivers/power/supply/ab8500_btemp.c
index 0fd24577112eb..0bec8b90667c8 100644
--- a/drivers/power/supply/ab8500_btemp.c
+++ b/drivers/power/supply/ab8500_btemp.c
@@ -919,10 +919,8 @@ static int ab8500_btemp_get_ext_psy_data(struct device *dev, void *data)
*/
static void ab8500_btemp_external_power_changed(struct power_supply *psy)
{
- struct ab8500_btemp *di = power_supply_get_drvdata(psy);
-
- class_for_each_device(power_supply_class, NULL,
- di->btemp_psy, ab8500_btemp_get_ext_psy_data);
+ class_for_each_device(power_supply_class, NULL, psy,
+ ab8500_btemp_get_ext_psy_data);
}
/* ab8500 btemp driver interrupts and their respective isr */
diff --git a/drivers/power/supply/ab8500_fg.c b/drivers/power/supply/ab8500_fg.c
index 675f9d0e8471e..d0cbd7189a622 100644
--- a/drivers/power/supply/ab8500_fg.c
+++ b/drivers/power/supply/ab8500_fg.c
@@ -2380,10 +2380,8 @@ static int ab8500_fg_init_hw_registers(struct ab8500_fg *di)
*/
static void ab8500_fg_external_power_changed(struct power_supply *psy)
{
- struct ab8500_fg *di = power_supply_get_drvdata(psy);
-
- class_for_each_device(power_supply_class, NULL,
- di->fg_psy, ab8500_fg_get_ext_psy_data);
+ class_for_each_device(power_supply_class, NULL, psy,
+ ab8500_fg_get_ext_psy_data);
}
/**
