[CVE-2026-80624][MODERATE REGULAR] mfd: cs42l43: Sanity check firmware size [ Upstream

[CVE-2026-80624][MODERATE REGULAR] mfd: cs42l43: Sanity check firmware size [ Upstream

[AL-KERNEL]

CVE: CVE-2026-80624
Priority: MODERATE REGULAR
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: mfd: cs42l43: Sanity check firmware size [ Upstream
Commit: 2ce02059ceb6311a33026b62e6e4dc4ed22a3aef
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=2ce02059ceb6311a33026b62e6e4dc4ed22a3aef
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80624
Analysis date: Fri, 28 Aug 2026 04:52:55 -0400
ActionableScore: 2
ActionableScore lower bound: 0
Actionable bucket: Ordinary Moderate / Low-like with manual review recommended
Manual review required: YES

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-80624 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80624

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-2026-80624	MODERATE	CHECK WITH IMPACT FROM ORIG NN IMPORTANT	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:H';CWE-125;*CWE-20;CWE-754;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '5.1';DESCR 'An out-of-bounds read can occur in cs42l43_mcu_load_firmware() because the driver only checked that a firmware object existed and did not verify that the firmware blob was large enough to contain the header. If a malformed or truncated firmware file is supplied, the code can treat bytes beyond the allocated firmware buffer as the header and then use invalid header fields during load processing. For the CVSS the PR:H is used for the selected paranoid score because reliable triggering normally requires administrative control over firmware files or driver loading on a system with the cs42l43 device. The issue is not network reachable and is a local firmware loading path. Impact is primarily denial of service or driver failure, with limited confidentiality risk from an invalid kernel read but no direct evidence of privilege escalation.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like with manual review recommended (with actual score 1)	YES	WRITE OOB SIMPLEFIX IMPROVEONLY LINUS  LOWERED_FROM_HIGH_BASED_ON_GUESSCVSS  DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5	YES	NO	checked

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

ActionableScore=2
ActionableScoreLower=0

### 1. ActionableScore

* Conservative score: 0
* Paranoid score: 2
* Final recommended bucket: **Ordinary Moderate / Low-like with manual review recommended**::

### 2. Signal breakdown

Conservative score:

* Firmware-mediated or firmware-file influence: +1. The affected input is a firmware blob consumed by the driver.
* Limited read-only OOB access: +0. The patch shows an out-of-bounds read risk, but not an OOB write, UAF, double free, or type confusion.
* Requires admin/root in typical deployments: -2. Supplying or replacing kernel firmware files and forcing driver reload is normally root-controlled.
* Rare hardware/device-specific path: -1. The issue is limited to systems with the cs42l43 device and this driver path.
* Conservative total is clamped to 0.

Paranoid score:

* Firmware-mediated or firmware-file influence: +1.
* Weak/indirect corruption candidate: +1. The kernel may interpret memory beyond the firmware buffer as a firmware header.
* Privileged driver/firmware loading memory-safety path: +1. The bug is in trusted kernel driver firmware parsing.
* Limited confidentiality impact plausible: +1. A kernel OOB read exists, but no clear disclosure channel is shown.
* Availability impact plausible: +1. Malformed header interpretation could cause driver failure or possibly an Oops in unfavorable layouts.
* Requires admin/root in typical deployments: -2.
* Rare hardware/device-specific path: -1.
* Paranoid total: 2.

### 3. Reachability analysis

The bug is triggered through the cs42l43 firmware loading path. In typical Linux deployments, firmware blobs under `/lib/firmware` are controlled by root or by the OS image, so reliable triggering normally requires administrative control over firmware contents, driver loading, or device initialization. This is not network reachable. Containers or namespaces do not normally reduce the privilege requirement unless the environment exposes firmware replacement or device-management control to a less privileged actor, which would be unusual and product-specific.

Call-site confidence: medium. The provided patch shows the vulnerable dereference guard in `cs42l43_mcu_load_firmware()`, but not the full downstream use of header fields.

### 4. Severity interpretation

This behaves like a low-end Moderate or Low-like kernel memory-safety issue. The concrete primitive is an out-of-bounds read from a malformed or truncated firmware blob. There is no evidence of attacker-controlled overwrite, reclaim, stale callback, refcount abuse, page-cache corruption, or practical privilege escalation. The paranoid score keeps it nonzero because OOB reads in kernel firmware parsing deserve manual validation, but this does not look like an Important-class candidate without additional evidence of unprivileged firmware control or a disclosure/corruption sink.

### 5. One-sentence report phrase

A malformed cs42l43 firmware blob smaller than the expected header can cause a kernel out-of-bounds read during firmware loading, but practical triggering typically requires administrative control over firmware files or driver initialization and no network or privilege-escalation path is shown.

### 6. Manual review recommendation

MANUAL CHECK RECOMMENDED.
YES REQUIRES MANUAL CHECK for confirmation of downstream header-field usage, but urgency is low because the trigger is normally privileged and device-specific.

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

Patch: mfd: cs42l43: Sanity check firmware size [ Upstream
Commit: 2ce02059ceb6311a33026b62e6e4dc4ed22a3aef
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=2ce02059ceb6311a33026b62e6e4dc4ed22a3aef

Changed files:
  drivers/mfd/cs42l43.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=2ce02059ceb6311a33026b62e6e4dc4ed22a3aef

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

The original Linux kernel CVE announcement for CVE-2026-80624 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80624

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:L/PR:H/UI:N/S:U/C:N/I:N/A:L
  The Best / paranoid CVSS vector: AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:H
  The Best / paranoid CVSS score: 5.1

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: 0
  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: 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).