Subject: CVE-2022-48735: ALSA: hda: Fix UAF of leds class devs at unbinding

From: Greg Kroah-Hartman <[email-masked]>

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.

The Linux kernel CVE team has assigned CVE-2022-48735 to this issue.

Affected and fixed versions
===========================

	Fixed in 5.10.99 with commit a7de1002135c
	Fixed in 5.15.22 with commit 0e629052f013
	Fixed in 5.16.8 with commit 813e9f3e06d2
	Fixed in 5.17 with commit 549f8ffc7b2f

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2022-48735
will be updated if fixes are backported, please check that for the most
up to date information about this issue.

Affected files
==============

The file(s) affected by this issue are:
	sound/pci/hda/hda_generic.c
	sound/pci/hda/hda_generic.h

Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	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