Patch "leds: trigger: Unregister sysfs attributes before calling deactivate()" has been added to the 4.19-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

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

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:
     leds-trigger-unregister-sysfs-attributes-before-call.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 a6450a6653dc2b05eb9c734c49867c7cfd90cbc8
Author: Hans de Goede <hdegoede@xxxxxxxxxx>
Date:   Sat May 4 18:25:33 2024 +0200

    leds: trigger: Unregister sysfs attributes before calling deactivate()
    
    [ Upstream commit c0dc9adf9474ecb7106e60e5472577375aedaed3 ]
    
    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: a7e7a3156300 ("leds: triggers: add device attribute support")
    Cc: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
    Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
    Acked-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
    Link: https://lore.kernel.org/r/20240504162533.76780-1-hdegoede@xxxxxxxxxx
    Signed-off-by: Lee Jones <lee@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
index ec4c957c36b6c..8738fc01523fd 100644
--- a/drivers/leds/led-triggers.c
+++ b/drivers/leds/led-triggers.c
@@ -125,9 +125,9 @@ int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
 			flags);
 		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;