6.11-stable review patch. If anyone has any objections, please let me know.
------------------
From: Hans de Goede <hdegoede@xxxxxxxxxx>
commit 78f281e5bdeb6476fab97a2c3fcece1094b42aaf upstream.
power_supply_property_is_writeable() gets called from the is_visible()
callback for the sysfs attributes of power_supply class devices and for
the sysfs attributes of power_supply core instantiated hwmon class devices.
These sysfs attributes get registered by the device_add() respectively
power_supply_add_hwmon_sysfs() calls in power_supply_register().
use_cnt gets initialized to 0 and is incremented only after these calls.
So when power_supply_property_is_writeable() gets called it always return
-ENODEV because of use_cnt == 0.
This causes all the attributes to have permissions of 444 even those which
should be writable. This used to be a problem only for hwmon sysfs
attributes but since commit be6299c6e55e ("power: supply: sysfs: use
power_supply_property_is_writeable()") this now also impacts power_supply
class sysfs attributes.
Fixes: be6299c6e55e ("power: supply: sysfs: use power_supply_property_is_writeable()")
Fixes: e67d4dfc9ff1 ("power: supply: Add HWMON compatibility layer")
Cc: stable@xxxxxxxxxxxxxxx
Cc: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
Cc: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Link: https://lore.kernel.org/stable/20240908185337.103696-1-hdegoede%40redhat.com
Link: https://lore.kernel.org/r/20240908185337.103696-1-hdegoede@xxxxxxxxxx
Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/power/supply/power_supply_core.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
--- a/drivers/power/supply/power_supply_core.c
+++ b/drivers/power/supply/power_supply_core.c
@@ -1232,11 +1232,7 @@ EXPORT_SYMBOL_GPL(power_supply_set_prope
int power_supply_property_is_writeable(struct power_supply *psy,
enum power_supply_property psp)
{
- if (atomic_read(&psy->use_cnt) <= 0 ||
- !psy->desc->property_is_writeable)
- return -ENODEV;
-
- return psy->desc->property_is_writeable(psy, psp);
+ return psy->desc->property_is_writeable && psy->desc->property_is_writeable(psy, psp);
}
EXPORT_SYMBOL_GPL(power_supply_property_is_writeable);
