leds: trigger: Unregister sysfs attributes before calling deactivate()

JIRA: https://issues.redhat.com/browse/RHEL-54835
CVE: CVE-2024-43830

commit c0dc9ad
Author: Hans de Goede <hdegoede@redhat.com>
Date:   Sat May 4 18:25:33 2024 +0200

    leds: trigger: Unregister sysfs attributes before calling deactivate()

    Triggers which have trigger specific sysfs attributes typically store
    related data in trigger-data allocated by the activate() callback and
    freed by the deactivate() callback.

    Calling device_remove_groups() after calling deactivate() leaves a window
    where the sysfs attributes show/store functions could be called after
    deactivation and then operate on the just freed trigger-data.

    Move the device_remove_groups() call to before deactivate() to close
    this race window.

    This also makes the deactivation path properly do things in reverse order
    of the activation path which calls the activate() callback before calling
    device_add_groups().

    Fixes: a7e7a31 ("leds: triggers: add device attribute support")
    Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
    Signed-off-by: Hans de Goede <hdegoede@redhat.com>
    Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
    Link: https://lore.kernel.org/r/20240504162533.76780-1-hdegoede@redhat.com
    Signed-off-by: Lee Jones <lee@kernel.org>

Signed-off-by: CKI Backport Bot <cki-ci-bot+cki-gitlab-backport-bot@redhat.com>

Author: CKI Backport Bot

drivers/leds/led-triggers.c

@@ -179,9 +179,9 @@ int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
 
 		cancel_work_sync(&led_cdev->set_brightness_work);
 		led_stop_software_blink(led_cdev);
+		device_remove_groups(led_cdev->dev, led_cdev->trigger->groups);
 		if (led_cdev->trigger->deactivate)
 			led_cdev->trigger->deactivate(led_cdev);
-		device_remove_groups(led_cdev->dev, led_cdev->trigger->groups);
 		led_cdev->trigger = NULL;
 		led_cdev->trigger_data = NULL;
 		led_cdev->activated = false;