HID: asus: use spinlock to safely schedule workers

Use spinlocks to deal with workers introducing a wrapper
asus_schedule_work(), and several spinlock checks.
Otherwise, asus_kbd_backlight_set() may schedule led->work after the
structure has been freed, causing a use-after-free.

Fixes: af22a610bc ("HID: asus: support backlight on USB keyboards")
Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it>
Link: https://lore.kernel.org/r/20230125-hid-unregister-leds-v4-5-7860c5763c38@diag.uniroma1.it
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
This commit is contained in:
Pietro Borrello 2023-02-12 19:00:03 +00:00 committed by Benjamin Tissoires
parent 315c537068
commit 4ab3a086d1

View file

@ -491,6 +491,16 @@ static int rog_nkey_led_init(struct hid_device *hdev)
return ret;
}
static void asus_schedule_work(struct asus_kbd_leds *led)
{
unsigned long flags;
spin_lock_irqsave(&led->lock, flags);
if (!led->removed)
schedule_work(&led->work);
spin_unlock_irqrestore(&led->lock, flags);
}
static void asus_kbd_backlight_set(struct led_classdev *led_cdev,
enum led_brightness brightness)
{
@ -502,7 +512,7 @@ static void asus_kbd_backlight_set(struct led_classdev *led_cdev,
led->brightness = brightness;
spin_unlock_irqrestore(&led->lock, flags);
schedule_work(&led->work);
asus_schedule_work(led);
}
static enum led_brightness asus_kbd_backlight_get(struct led_classdev *led_cdev)
@ -526,9 +536,6 @@ static void asus_kbd_backlight_work(struct work_struct *work)
int ret;
unsigned long flags;
if (led->removed)
return;
spin_lock_irqsave(&led->lock, flags);
buf[4] = led->brightness;
spin_unlock_irqrestore(&led->lock, flags);