From: Pietro Borrello borrello@diag.uniroma1.it
commit 4ab3a086d10eeec1424f2e8a968827a6336203df upstream.
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: af22a610bc38 ("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@dia... Signed-off-by: Benjamin Tissoires benjamin.tissoires@redhat.com Signed-off-by: Stefan Ghinea stefan.ghinea@windriver.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/hid/hid-asus.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-)
--- a/drivers/hid/hid-asus.c +++ b/drivers/hid/hid-asus.c @@ -294,6 +294,16 @@ static int asus_kbd_get_functions(struct 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) { @@ -305,7 +315,7 @@ static void asus_kbd_backlight_set(struc 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) @@ -329,9 +339,6 @@ static void asus_kbd_backlight_work(stru 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);