6.11-stable review patch. If anyone has any objections, please let me know.
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From: Hans de Goede hdegoede@redhat.com
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@vger.kernel.org Cc: Thomas Weißschuh linux@weissschuh.net Cc: Andrey Smirnov andrew.smirnov@gmail.com Signed-off-by: Hans de Goede hdegoede@redhat.com Link: https://lore.kernel.org/stable/20240908185337.103696-1-hdegoede%40redhat.com Link: https://lore.kernel.org/r/20240908185337.103696-1-hdegoede@redhat.com Signed-off-by: Sebastian Reichel sebastian.reichel@collabora.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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);