[CVE-2026-68346][LOW] ALSA: hda: cs35l41: validate and free ACPI mute object [ Upstream

[AL-KERNEL <alkernel@kernelcve.org>]

CVE: CVE-2026-68346
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: ALSA: hda: cs35l41: validate and free ACPI mute object [ Upstream
Commit: 7fea0c89ed39a13d9a31163a74f8c62de30a4ffc
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7fea0c89ed39a13d9a31163a74f8c62de30a4ffc
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68346
Analysis date: Mon, 10 Aug 2026 20:08:42 -0400
ActionableScore: 2
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate / Low-like
Manual review required: NO

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-68346 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68346

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: LOW
Manual review required: NO

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

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

CVE-2026-68346	LOW	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:L/UI:N/S:U/C:N/I:N/A:H';*CWE-401;*CWE-20;**CWE-476;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.7';DESCR 'The cs35l41 HDA driver reads the first byte of an ACPI DSM mute response without validating that the returned object is a non empty buffer. A malformed firmware response can make the driver dereference an invalid or NULL buffer pointer, causing a local kernel crash on affected hardware. The same path also leaks the returned ACPI object on each successful query, so repeated queries may cause gradual kernel memory growth. For the CVSS the PR:L is used for the paranoid score because a local user or local process may be able to trigger mute state queries on a system with this codec, but the malformed object itself is normally controlled by platform firmware rather than a remote attacker. The issue is not network reachable. Impact is primarily denial of service, with no supported evidence of information disclosure or privilege escalation.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 2)	YES	INIT LEAK UAF HARDWARE LINUS 	NO	NO	checked

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

ActionableScore=2

1. ActionableScore
* Conservative score: 2
* Paranoid score: 2
* Final recommended bucket: **Ordinary Moderate / Low-like**

2. Signal breakdown
* Firmware-mediated external influence: +1. The malformed object comes from ACPI firmware or platform tables, not from a normal remote attacker.
* Local unprivileged trigger: +1. A local user or local audio stack process may be able to cause mute-state queries on affected hardware.
* Reliable kernel crash / strong DoS: +0. The invalid pointer dereference can crash, but it depends on malformed firmware response and is not clearly attacker-controlled in normal deployments.
* Generic memory corruption: +0. This is an invalid or NULL pointer dereference and a leak, not UAF, double-free, OOB write, arbitrary write, or type confusion.
* Privilege escalation plausible: +0. No reclaim, write primitive, callback control, refcount abuse, or object replacement is shown.
* Availability impact realistic: +1 would be possible in a more aggressive reading, but I do not add it separately because the practical crash path is firmware-dependent and the leak appears gradual.
* Rare hardware / firmware-dependent condition: -1. The issue requires affected CS35L41 HDA systems and a malformed or unusual ACPI _DSM response.

Net practical score: 1 + 1 - 1 plus low DoS concern rounded to 2.

3. Reachability analysis
A local user or local userspace audio component may be able to trigger the mute-state query path on systems with this codec. The malformed object itself is normally controlled by firmware or ACPI tables, so this is not realistically network-triggerable. Containers and namespaces do not meaningfully improve reachability unless they can access the relevant host audio device path. The bug is hardware and firmware dependent and is not a broad default kernel attack surface.

4. Severity interpretation
This behaves more like an ordinary Moderate or Low-like issue. The patch fixes a memory leak and validates an ACPI object before dereferencing its buffer pointer. Theoretical impact is local DoS through invalid pointer dereference or gradual memory growth. Realistic exploitation evidence for privilege escalation, confidentiality impact, integrity impact, UAF, OOB write, or attacker-controlled memory corruption is not present.

5. One-sentence report phrase
The CS35L41 HDA driver failed to validate and free an ACPI DSM mute response, allowing malformed firmware data to cause an invalid pointer dereference or repeated object leaks on affected local systems.

6. Manual review recommendation
NO MANUAL CHECK NEEDED.
This is a firmware-dependent local DoS or leak issue without a demonstrated memory corruption primitive, privilege escalation path, network reachability, or broad default exposure.

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

Patch: ALSA: hda: cs35l41: validate and free ACPI mute object [ Upstream
Commit: 7fea0c89ed39a13d9a31163a74f8c62de30a4ffc
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7fea0c89ed39a13d9a31163a74f8c62de30a4ffc

Changed files:
  sound/pci/hda/cs35l41_hda.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=7fea0c89ed39a13d9a31163a74f8c62de30a4ffc

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

The original Linux kernel CVE announcement for CVE-2026-68346 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68346

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:L/UI:N/S:U/C:N/I:N/A:L
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS score: 4.7

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: unknown
  Paranoid ActionableScore: 2

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: LOW
KPANIC detected for this report: NO
Published priority for this report (same as in Subject): LOW

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).