From: Pietro Borrello <borrello@xxxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230125-hid-unregister-leds-v4-5-7860c5763c38@xxxxxxxxxxxxxxxx
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
Signed-off-by: Stefan Ghinea <stefan.ghinea@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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);
