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.
Reported-by: Alexander Sergeyev <sergeev917@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220111195229.a77wrpjclqwrx4bx@localhost.localdomain
Link: https://lore.kernel.org/r/20220126145011.16728-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2 files changed