[CVE-2026-64041][MODERATE 7.0] ASoC: codecs: fs210x: fix possible buffer overflow [ Upstream

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

CVE: CVE-2026-64041
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: ASoC: codecs: fs210x: fix possible buffer overflow [ Upstream
Commit: 1ddf678bb75b6383c775ece61d40956c441d8a26
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=1ddf678bb75b6383c775ece61d40956c441d8a26
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64041
Analysis date: Sun, 19 Jul 2026 19:19:03 -0400
ActionableScore: 5
ActionableScore lower bound: 4
Actionable bucket: Actionable Moderate at minimum
Manual review required: YES

Summary:
A possible kernel buffer overflow in the FS210x ALSA codec control path can occur because `strscpy()` used the source string length rather than the destination buffer size, making this a local memory-corruption candidate requiring manual review.

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ABOUT THIS REPORT
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The original Linux kernel CVE announcement for CVE-2026-64041 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64041

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 7.0
Manual review required: YES

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
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CVE-2026-64041	MODERATE	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:H/I:H/A:H';*CWE-787;CWE-120;CWE-121;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H';BEST CVSS score: '7';DESCR 'A buffer overflow can occur in fs210x_effect_scene_info() because strscpy() used the source string length as the copy bound instead of the destination buffer size. If an fs210x scene name is longer than the ALSA enumerated control name buffer, the copy can write past uinfo value enumerated name and corrupt adjacent kernel memory. For the CVSS the PR:L is used because triggering the vulnerable path requires a local user or process able to access the ALSA control interface, not a remote network attacker. The issue is not network reachable and depends on the affected fs210x codec driver and scene name data being present. Impact is at least local denial of service via kernel crash and in the paranoid interpretation may allow confidentiality or integrity impact because the primitive is a kernel out of bounds write.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate at minimum (with actual score 5)  SKIP CVE-2026-64041 UNKNOWN SKIP No affected files built, so skip this CVE NO  - - unknown 	MAYBE	OOB SIMPLEFIX HARDWARE KPANIC 	-	-	checked

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ACTIONABLESCORE ANALYSIS
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ActionableScore=5
ActionableScoreLower=4

## 1. ActionableScore

* Conservative score: 4
* Paranoid score: 5
* Final recommended bucket: **Actionable Moderate at minimum**

## 2. Signal breakdown

Conservative signals:

* Local unprivileged trigger: +1
  The affected path is an ALSA control info callback and can plausibly be reached by a local user or process with access to the sound device.

* Constrained kernel buffer overwrite: +1
  The bug is an incorrect `strscpy()` bound where `strlen(src) + 1` is used instead of the destination buffer size. This can overflow `uinfo->value.enumerated.name`.

* Weak LPE concern: +1
  This is a kernel out-of-bounds write candidate, but the copied string appears to come from driver scene metadata rather than directly attacker-controlled input. That makes privilege escalation theoretically relevant but not strongly demonstrated.

* Availability impact realistic: +1
  Kernel memory corruption in an ALSA codec callback can plausibly crash the kernel or destabilize the sound subsystem.

Paranoid additional interpretation:

* Generic memory corruption, stronger interpretation: +1 additional
  Because the patch explicitly fixes a possible buffer overflow in kernel code, the paranoid score treats it as a stronger memory-corruption candidate even though payload and target control appear constrained.

No remote/network signal is applied. No Dirty-Pipe-like, page-cache, lifetime, RCU, or security-boundary-bypass signal is supported by the patch.

## 3. Reachability analysis

The likely trigger is local access to ALSA control enumeration for an affected FS210x codec device. This is not network reachable. In typical systems the attacker would need local code execution and access to the relevant sound device node, so this is not PR:N in practical CVSS terms.

Namespaces and containers matter only if the sound device is delegated into the container. Without access to the ALSA device, the path is not reachable from a container. The driver and hardware are device-specific, so exposure is much narrower than core ALSA or networking code, but on affected embedded or audio devices the path may be ordinary local functionality.

Call-site confidence: medium. The patch provides the vulnerable callback body but not the full ALSA registration and call chain. The ALSA control callback pattern is well known enough to infer local reachability.

## 4. Severity interpretation

This is not an ordinary low-risk cleanup because the patch explicitly fixes a possible kernel buffer overflow. It is also not a strong Important candidate by default because the source string and overwrite target appear constrained, and there is no demonstrated reclaim, arbitrary write, type confusion, callback overwrite, or privilege escalation chain.

Realistically, this behaves like an Actionable Moderate memory-corruption issue requiring manual review. Theoretical impact includes local kernel crash and possible limited privilege-escalation concern. Practical exploitation evidence is weak from the patch alone.

## 5. One-sentence report phrase

A possible kernel buffer overflow in the FS210x ALSA codec control path can occur because `strscpy()` used the source string length rather than the destination buffer size, making this a local memory-corruption candidate requiring manual review.

## 6. Manual review recommendation

MANUAL CHECK REQUIRED

Reason: this is an explicit kernel buffer overflow candidate. Even though the overwrite appears constrained and hardware-specific, memory corruption in kernel code should not be auto-closed without checking source control of `scene->name`, destination object layout, and actual ALSA control reachability on affected products.

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

Patch: ASoC: codecs: fs210x: fix possible buffer overflow [ Upstream
Commit: 1ddf678bb75b6383c775ece61d40956c441d8a26
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=1ddf678bb75b6383c775ece61d40956c441d8a26

Changed files:
  sound/soc/codecs/fs210x.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=1ddf678bb75b6383c775ece61d40956c441d8a26

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

The original Linux kernel CVE announcement for CVE-2026-64041 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64041

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:L/I:L/A:H
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
  The Best / paranoid CVSS score: 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: 4
  Paranoid ActionableScore: 5

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: YES
Published priority for this report (same as in Subject): MODERATE 7.0

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).