ALSA: hda: Fix UAF of leds class devs at unbinding

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: hda: Fix UAF of leds class devs at unbinding The LED class devices that are created by HD-audio codec drivers are registered via devm_led_classdev_register() and associated with the HD-audio codec device. Unfortunately, it turned out that the devres release doesn't work for this case; namely, since the codec resource release happens before the devm call chain, it triggers a NULL dereference or a UAF for a stale set_brightness_delay callback. For fixing the bug, this patch changes the LED class device register and unregister in a manual manner without devres, keeping the instances in hda_gen_spec.

References

• https://git.kernel.org/stable/c/a7de1002135cf94367748ffc695a29812d7633b5
• https://git.kernel.org/stable/c/0e629052f013eeb61494d4df2f1f647c2a9aef47
• https://git.kernel.org/stable/c/813e9f3e06d22e29872d4fd51b54992d89cf66c8
• https://git.kernel.org/stable/c/549f8ffc7b2f7561bea7f90930b6c5104318e87b