CVE-2026-80828: ALSA: usb-audio: Complete cleanup after system-resume errors

CVE-2026-80828: ALSA: usb-audio: Complete cleanup after system-resume errors

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

ALSA: usb-audio: Complete cleanup after system-resume errors

A failed system resume can leave the card unusable until reboot.
usb_audio_resume() jumps to err_out when snd_usb_pcm_resume() or
snd_usb_mixer_resume() fails. The error path skips the out: block, which
restores D0 and decrements chip->num_suspended_intf.

The card stays in SNDRV_CTL_POWER_D3hot, so later control access blocks in
snd_power_ref_and_wait(). USB core logs an interface resume callback error.
It does not retry that callback, so a later callback cannot complete the
skipped cleanup.

usb_audio_suspend() increments num_suspended_intf before returning success.
A system-resume callback must consume the system-suspend count even if a
component resume fails. Otherwise, the stranded count skews later suspend
and resume cycles.

Do not apply this cleanup to runtime-resume errors. Runtime PM can retry
-EAGAIN or -EBUSY without another suspend callback. The count must continue
to describe that suspended interface. Other runtime-resume errors latch
runtime_error in the PM core and do not cause an immediate callback retry.

Both parts of the system-resume error path are longstanding. Commit
88a8516a2128a ("ALSA: usbaudio: implement USB autosuspend") introduced
err_out past the D0 restore. Commit 862b2509d157c ("ALSA: usb-audio: Fix
inconsistent card PM state after resume") later moved
num_suspended_intf-- into the out: block. The error path now skips both
operations.

No third-party code is needed to reach the error path.
snd_usb_mixer_resume() ends in snd_usb_mixer_activate(), which returns the
result of usb_submit_urb() for devices that have a mixer status URB. Its
mixer->private_resume hook can also fail through scarlett2_init_notify().
snd_usb_pcm_resume() issues a SET_CUR request to a UAC3 power domain. It
can return -EPIPE or -EIO when the device stalls the request.

Route a component error through out: only when system_suspend is nonzero.
Continue to return runtime-resume errors through err_out. Later component
resume stages remain skipped. The original error still reaches USB core.
A later transfer can fail if the device did not recover.

I reproduced the system-resume failure on an Audient iD14 MkI with an
out-of-tree diagnostic mixer resume hook. An injected -EIO on the unpatched
core left control readers in uninterruptible sleep in
snd_power_ref_and_wait() until a reboot. With this patch, the same failure
restored control access. A second system suspend and resume also succeeded
after I disabled fault injection.

The Linux kernel CVE team has assigned CVE-2026-80828 to this issue.


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

	Issue introduced in 2.6.39 with commit 88a8516a2128a6d078a106ead48092240e8a138f and fixed in 5.15.220 with commit 3fa521c3c54b42e16cad8ade76551113a783752b
	Issue introduced in 2.6.39 with commit 88a8516a2128a6d078a106ead48092240e8a138f and fixed in 6.1.187 with commit 3f06f3f5b16212f180764654a9398ff5f7a855c8
	Issue introduced in 2.6.39 with commit 88a8516a2128a6d078a106ead48092240e8a138f and fixed in 6.6.156 with commit f1c05c41d07b874635d681ae328d13ec550470c5
	Issue introduced in 2.6.39 with commit 88a8516a2128a6d078a106ead48092240e8a138f and fixed in 6.12.108 with commit 5a625fc2284e35f33693efd9534aebaca3b005d4
	Issue introduced in 2.6.39 with commit 88a8516a2128a6d078a106ead48092240e8a138f and fixed in 6.18.49 with commit 6d3e202670b819c414076a5d07dffac8a39274ad
	Issue introduced in 2.6.39 with commit 88a8516a2128a6d078a106ead48092240e8a138f and fixed in 7.1.13 with commit 6c94877b6bab9185898bcad4b082ff5592558921
	Issue introduced in 2.6.39 with commit 88a8516a2128a6d078a106ead48092240e8a138f and fixed in 7.2.3 with commit d1f643b1c0258bd519146f7a342bbb394d413912
	Issue introduced in 2.6.39 with commit 88a8516a2128a6d078a106ead48092240e8a138f and fixed in 7.3-rc1 with commit 1739a976312e110c93a8dee66a1cdf893a1b187e

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-2026-80828
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/usb/card.c


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/3fa521c3c54b42e16cad8ade76551113a783752b
	https://git.kernel.org/stable/c/3f06f3f5b16212f180764654a9398ff5f7a855c8
	https://git.kernel.org/stable/c/f1c05c41d07b874635d681ae328d13ec550470c5
	https://git.kernel.org/stable/c/5a625fc2284e35f33693efd9534aebaca3b005d4
	https://git.kernel.org/stable/c/6d3e202670b819c414076a5d07dffac8a39274ad
	https://git.kernel.org/stable/c/6c94877b6bab9185898bcad4b082ff5592558921
	https://git.kernel.org/stable/c/d1f643b1c0258bd519146f7a342bbb394d413912
	https://git.kernel.org/stable/c/1739a976312e110c93a8dee66a1cdf893a1b187e