[CVE-2026-80872][MODERATE REGULAR] ALSA: hda/tas2781: Cancel async firmware request at unbind [ Upstream

[CVE-2026-80872][MODERATE REGULAR] ALSA: hda/tas2781: Cancel async firmware request at unbind [ Upstream

[AL-KERNEL]

CVE: CVE-2026-80872
Priority: MODERATE REGULAR
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: ALSA: hda/tas2781: Cancel async firmware request at unbind [ Upstream
Commit: f8272331da877eec8fe8e89a1e98e6a710e12490
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f8272331da877eec8fe8e89a1e98e6a710e12490
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80872
Analysis date: Fri, 04 Sep 2026 18:36:43 -0400
ActionableScore: 3
ActionableScore lower bound: 2
Actionable bucket: Borderline Moderate, manual review recommended
Manual review required: YES

Summary:
No one-sentence report phrase was found.

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ABOUT THIS REPORT
======================================================================

The original Linux kernel CVE announcement for CVE-2026-80872 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80872

The original announcement does not normally provide a security severity
estimate, CVSS assessment, or enough information to determine whether the
reported kernel bug represents a practically relevant security issue.

This report was generated by AL-KERNEL, an AI-assisted Linux kernel
vulnerability analysis system developed by Alexander Larkin. It combines
an autonomous classifier with LLM-assisted technical analysis and a
separate ActionableScore mechanism.

The purpose of this report is to prioritize Linux kernel CVEs before
manual review, identify cases that require prompt investigation, and
support automatic closure of issues that are unlikely to have meaningful
security impact.

Published priority for this report: MODERATE REGULAR
Manual review required: YES

A detailed explanation of the methodology and priority rules is included
at the end of this message.

======================================================================
AL-KERNEL CLASSIFICATION RESULT
======================================================================

CVE-2026-80872	MODERATE	https://www.kernelcve.org/list/?q=CVE-2026-80872 CHECK WITH IMPACT FROM ORIG NN LOW	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:H';CWE-362;*CWE-416;*CWE-664;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '5.2';DESCR 'An async firmware callback in the ALSA HDA TAS2781 driver can race with component unbind. The callback may still use driver private HDA state after controls and DSP state have started teardown, and later teardown can free private data including codec_lock. This creates a use after free candidate and can lead to a kernel crash or other availability failure. For the CVSS the PR:H is selected because reliable triggering normally requires administrative control over driver unbind, device removal, module unload, or the affected device lifecycle on the host. The issue is not network reachable. Impact is at least local denial of service. In the worst defensible case, limited confidentiality or integrity impact is possible due to the UAF class, but there is no clear arbitrary write primitive in the patch context.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline Moderate, manual review recommended (with actual score 3)	YES	USB SIMPLEFIX HARDWARE LINUS  INCREASED_FROM_LOW_BASED_ON_REQUIREMANUALCHECK DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4	YES	NO	checked

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ACTIONABLESCORE ANALYSIS
======================================================================

ActionableScore=3
ActionableScoreLower=2

1. ActionableScore
* Conservative score: 2
* Paranoid score: 3
* Final recommended bucket: **Borderline Moderate, manual review recommended**

2. Signal breakdown
* Real lifetime corruption: +1. The async firmware callback can run while TAS2781 driver private state is being torn down.
* Memory corruption, weak primitive: +1. This is a UAF candidate because the callback can access driver-private state after unbind starts, but the patch does not show controlled reclaim, overwrite, type confusion, or arbitrary write.
* Reliable kernel crash / strong DoS: +1 in paranoid scoring. A stale callback using freed or partially removed state can plausibly crash the kernel.
* Hard or unreliable race / special timing required: -1. Triggering depends on timing between async firmware completion and component unbind/device teardown.
* Requires admin/root/device lifecycle control: -2. Reliable triggering normally requires unbind, module removal, device removal, or similar privileged device lifecycle control.
* Hardware/device-specific exposure: not scored as broad exposure. The affected path requires TAS2781 HDA I2C or SPI hardware and the corresponding driver path.

3. Reachability analysis
The bug is local and not network reachable. A realistic trigger requires control over the affected device lifecycle, such as component unbind, module unload, or device removal while an async firmware request is pending or running. In typical deployments this requires administrative privileges, so PR:H is the practical interpretation. Container or namespace delegation is unlikely to make this broadly reachable unless the container is given unusual host device-management privileges.

4. Severity interpretation
This behaves like a privileged local teardown race with a UAF candidate and likely DoS impact. Theoretical memory corruption exists because callback code can operate on driver-private state during teardown, but the patch does not show attacker-controlled reclaim, object replacement, arbitrary write, or a strong LPE primitive. It should not be treated as an Important candidate by default, but manual review is reasonable because lifetime bugs in async callbacks are often under-described.

5. One-sentence report phrase
An async firmware callback in the ALSA HDA TAS2781 driver can race with component unbind and access driver-private state during teardown, creating a UAF candidate that can plausibly cause a local kernel crash, with reliable triggering typically requiring privileged device lifecycle control.

6. Manual review recommendation
MANUAL CHECK REQUIRED. The issue is not high scoring, but it is a real async lifetime race with a UAF candidate, so it should not be auto-closed without checking whether callback state access can reach freed objects or writable teardown structures.

======================================================================
UPSTREAM PATCH SUMMARY
======================================================================

Patch: ALSA: hda/tas2781: Cancel async firmware request at unbind [ Upstream
Commit: f8272331da877eec8fe8e89a1e98e6a710e12490
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f8272331da877eec8fe8e89a1e98e6a710e12490

Changed files:
  sound/hda/codecs/side-codecs/tas2781_hda_i2c.c
  sound/hda/codecs/side-codecs/tas2781_hda_spi.c

Diff excerpt:

Not included in this email. See the upstream URL for the full patch.

Full patch:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f8272331da877eec8fe8e89a1e98e6a710e12490

======================================================================
DETAILED REPORT METHODOLOGY
======================================================================

The original Linux kernel CVE announcement for CVE-2026-80872 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80872

The original CVE announcement normally does not include a security-level
estimate. In particular, it may not contain a CVSS assessment, an impact
level, or enough information to determine whether the reported bug is a
practically relevant security issue. One purpose of this parallel CVE list
is to provide that missing technical and prioritization information.

The original goal of the AL-KERNEL project was to prioritize Linux kernel
CVE analysis automatically before manual review. The system can also help
identify non-security issues that may be suitable for automatic closure.

This report was generated by AL-KERNEL, an AI-assisted Linux kernel
vulnerability analysis system developed by Alexander Larkin.

The first analysis stage combines an autonomous classifier with additional
LLM-based analysis. The autonomous classifier runs locally on a CPU and is
based on a backpropagation neural network. Together, these mechanisms
produce a technical vulnerability description, identify likely weakness
types, estimate CVSS severity, and provide input for ActionableScore.

Two CVSS estimates are retained because incomplete kernel vulnerability
information often permits more than one defensible interpretation:

  Conservative CVSS vector: AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:H
  The Best / paranoid CVSS score: 5.2

The conservative vector represents a lower-impact interpretation.
The Best/paranoid vector intentionally represents a plausible upper-bound
interpretation and should not automatically be treated as demonstrated
real-world impact.

CVSS may also need to be adjusted for a particular Linux deployment,
because actual reachability, privileges, enabled kernel configuration,
hardware, namespaces, exposed device nodes, and other environmental
conditions can differ significantly between systems.

A separate ActionableScore mechanism evaluates practical remediation
urgency. Its analysis may include reachability, attack prerequisites,
subsystem exposure, memory-corruption characteristics, denial-of-service
reliability, and possible confidentiality, integrity, or
privilege-escalation impact.

  Conservative ActionableScore: 2
  Paranoid ActionableScore: 3

The final base severity is taken directly from the second tab-separated
field of the AL-KERNEL classification result. ActionableScore does not
replace or independently override that final AL-KERNEL decision, and
if ActionableScore adjusted impact level of ALKERNEL, then you would see
self-readable flags above like INCREASED_TO_HIGH_BASED_ON_ACTIONABLESCOREHIGHEREQTHAN7.

For an AL-KERNEL result of MODERATE, this report uses the following
additional presentation split:

  ActionableScore below 5   -> MODERATE REGULAR
  ActionableScore 5 or more -> MODERATE 7.0

The distinction between MODERATE REGULAR and MODERATE 7.0 makes it
possible to identify Moderate issues that should receive manual analysis
and fixes before lower-priority MODERATE REGULAR issues. In many cases,
MODERATE REGULAR fixes may wait for a later rebase or routine update.

There is one override in which MODERATE REGULAR becomes MODERATE 7.0
even when the ActionableScore is below 5. When the AL-KERNEL result
contains the KPANIC flag, a MODERATE result is always presented as
MODERATE 7.0. The KPANIC flag selected with few regexps without
usage of AI at all, so it helps to detect cases when Kernel Crash happens
and similar (to filter False-Negative results from the LLM usage).

KPANIC indicates that a reliable kernel crash, kernel panic, or similarly
serious kernel availability impact was identified by the classification
workflow.

AL-KERNEL base severity for this report: MODERATE
KPANIC detected for this report: NO
Published priority for this report (same as in Subject): MODERATE REGULAR

These results are intended to support engineering triage. They are
machine-generated estimates, and cases marked for manual review should
be validated by a human security engineer before final disposition.
For more info read docs linked from here: https://kernelcve.org/
(and you can submit you own patch there to generate such a report
for non-existant CVE-id yet).

Note that in many cases this AI tool selects higher severity, than
real is (means you can expect Importants instead of Moderate 7.0 or
Moderates 7.0 instead of regular Moderates). If you see such cases,
please use reply email interface to add additional manual analyses
info to this particular CVE.
And please, please, let me know when you see Lows instead of Importants
or Important instead of Low (because particular for such cases I
need to tune this AI tool to make it better for this one and next similar).
My contact email for such notifications is alexanjelausa@gmail.com (and both
send reply to CVE record itself too and see "reply" button below for howto reply).