[CVE-2026-72258][LOW] ASoC: mediatek: mt8183: Release reserved memory on cleanup

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

CVE: CVE-2026-72258
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: ASoC: mediatek: mt8183: Release reserved memory on cleanup
Commit: 48b6c39883637b444c2f976e7b8ca964b1889561
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=48b6c39883637b444c2f976e7b8ca964b1889561
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72258
Analysis date: Sat, 15 Aug 2026 15:39:11 -0400
ActionableScore: 0
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate / Low-like
Manual review required: NO

Summary:
The MT8183 AFE driver failed to release a reserved-memory device association on removal or later probe failure paths, which may cause a privileged local resource leak but does not expose memory corruption, privilege escalation, or network reachability.

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

The original Linux kernel CVE announcement for CVE-2026-72258 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72258

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
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CVE-2026-72258	LOW	CHECK WITH IMPACT FROM ORIG NN LOW	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H';*CWE-772;CWE-404;*CWE-401;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.4';DESCR 'The MT8183 AFE driver can assign reserved memory through of_reserved_mem_device_init() but the assignment was not released on driver removal or later probe failure paths. This can leave a reserved memory device association behind and may cause a resource leak across repeated probe or remove cycles. For the CVSS the PR:H is used because reliable triggering normally requires administrative control over platform driver binding, module handling, or probe failure conditions. The issue is not network reachable and is not triggered by audio data traffic. Impact is denial of service through resource leakage only, with no evidence of UAF, OOB access, information disclosure, or privilege escalation.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 0)  SKIP CVE-2026-72258 UNKNOWN SKIP No affected files built, so skip this CVE NO  - - unknown 	MAYBE	SIMPLEFIX HARDWARE 	-	-	checked

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ACTIONABLESCORE ANALYSIS
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## 1. ActionableScore

ActionableScore=0

* Conservative score: 0
* Paranoid score: 0
* Final recommended bucket: **Ordinary Moderate / Low-like**

## 2. Signal breakdown

Triggered or considered signals:

* Resource leak / missing cleanup: +0
  The patch adds `of_reserved_mem_device_release()` via `devm_add_action_or_reset()`. This is a cleanup/resource lifetime fix, not a demonstrated memory corruption primitive.

* Availability impact realistic: +1 considered, but not retained after penalties
  Repeated probe failure or driver remove cycles could theoretically leave reserved memory associations behind and cause resource pressure, but this requires privileged device-management actions and is not an easy unprivileged DoS.

* Requires admin/root/CAP_* in typical deployments: -2
  Reliable triggering normally requires control over platform driver bind/unbind, module/device lifecycle, or inducing probe failure paths.

* Rare or hardware-specific path: -1
  This is specific to the Mediatek MT8183 AFE driver and requires the affected SoC/platform and reserved-memory configuration.

Net result is floored at 0.

No signals for:

* Remote reachability
* Local unprivileged trigger
* UAF, double-free, OOB access, type confusion, refcount abuse, or arbitrary write
* Privilege escalation
* Confidentiality or integrity impact
* Dirty-Pipe-like or page-cache/shared-page corruption

## 3. Reachability analysis

The affected path is the MT8183 AFE platform driver probe/remove cleanup path. A normal local user cannot usually trigger this directly. Practical triggering requires administrative control over driver/device lifecycle or the ability to cause repeated probe failures on affected hardware.

Namespaces or containers do not normally lower this to an unprivileged attack surface unless a container is explicitly given dangerous device-management privileges. The path is not network reachable and is not triggered by audio stream data.

Call-site confidence: high, because the patch directly shows the allocation/association cleanup path and the registered devm release action.

## 4. Severity interpretation

This behaves like a Low-like or ordinary Moderate resource cleanup issue, not an actionable Moderate or Important candidate. The realistic impact is limited to resource leakage across privileged probe/remove or failure paths.

There is no evidence in the patch of memory corruption, stale pointer dereference, writable UAF, object reuse, security-boundary bypass, or privilege escalation. The theoretical worst case remains resource exhaustion under repeated privileged manipulation, which is not enough for manual Important-class handling.

## 5. One-sentence report phrase

The MT8183 AFE driver failed to release a reserved-memory device association on removal or later probe failure paths, which may cause a privileged local resource leak but does not expose memory corruption, privilege escalation, or network reachability.

## 6. Manual review recommendation

NO MANUAL CHECK NEEDED

This can be auto-closed or handled in normal maintenance because it is a privileged, hardware-specific resource leak with no demonstrated corruption primitive or security-boundary bypass.

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

Patch: ASoC: mediatek: mt8183: Release reserved memory on cleanup
Commit: 48b6c39883637b444c2f976e7b8ca964b1889561
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=48b6c39883637b444c2f976e7b8ca964b1889561

Commit description:

The MT8183 AFE probe can assign reserved memory with
of_reserved_mem_device_init(), but the assignment is never released on
driver removal or later probe failures.

Register a devm cleanup action so the reserved memory assignment is
released consistently, matching newer Mediatek AFE drivers.

Fixes: ec4a10c ("ASoC: mediatek: use reserved memory or enable buffer pre-allocation")
Cc: stable@vger.kernel.org
Signed-off-by: Cássio Gabriel <cassiogabrielcontato@gmail.com>
Link: https://patch.msgid.link/20260527-asoc-mt8183-probe-cleanup-v1-1-4f4f5593c8d1@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  sound/soc/mediatek/mt8183/mt8183-afe-pcm.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=48b6c39883637b444c2f976e7b8ca964b1889561

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

The original Linux kernel CVE announcement for CVE-2026-72258 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72258

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:N/I:N/A:H
  The Best / paranoid CVSS score: 4.4

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: 0

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).