[CVE-2026-98958][MODERATE REGULAR] wifi: mt76: account non-AQL frames per peer rather than per link [ Upstream

[CVE-2026-98958][MODERATE REGULAR] wifi: mt76: account non-AQL frames per peer rather than per link [ Upstream

[AL-KERNEL]

CVE: CVE-2026-98958
Priority: MODERATE REGULAR
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: wifi: mt76: account non-AQL frames per peer rather than per link [ Upstream
Commit: 9f28f504650869d41f7b3e98e4bc4547af4d5670
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=9f28f504650869d41f7b3e98e4bc4547af4d5670
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98958
Analysis date: Tue, 27 Oct 2026 01:33:08 -0400
ActionableScore: 3
ActionableScore lower bound: 2
Actionable bucket: Borderline / manual review recommended
Manual review required: YES

Summary:
An adjacent MLO peer may induce mismatched per-link non-AQL accounting that eventually blocks its station’s transmissions, without evidence of kernel memory corruption or host-wide failure.

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

The original Linux kernel CVE announcement for CVE-2026-98958 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98958

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.

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

CVE-2026-98958	MODERATE	https://www.kernelcve.org/list/?q=CVE-2026-98958 CHECK WITH IMPACT FROM ORIG NN LOW | AEGIS IMPACT MODERATE AEGIS_AS=1 LEGACY=MODERATE RESULT=SAME (final reconciliation agrees; DECISION: both MODERATE)	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H';CWE-682;*CWE-664;Other CVSS 'AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '6.5';DESCR 'The mt76 driver can increment and decrement non-AQL packet counters on different link WCIDs when MLO hardware completes transmission on a link other than the one selected during queueing. The resulting counter drift can reach MT_MAX_NON_AQL_PKT and stop further transmission for the affected station. For the CVSS the PR:N value reflects that no local account or kernel privilege is needed when an adjacent MLO peer can stimulate the required traffic, although reliable control over hardware link selection is not established. The demonstrated impact is peer specific wireless denial of service with no evidence of memory corruption, information disclosure, data modification, or privilege escalation. Automated impact decision path. The original SimpleNet classifier selected MODERATE_KPANIC. The primary LLM estimated paranoid CVSS 6.5 and the production ActionableScore returned 3 with recommendation Borderline / manual review recommended. The production rules then evaluated CVSS thresholds and ActionableScore thresholds. Recorded rule transitions were ActionableScore thresholds stage MODERATE_KPANIC to MODERATE because the ActionableScore threshold rule was applied. The legacy KP specialist has no review artifact for this run. The legacy FD or DH downgrade specialist has no review artifact for this run. Exact triggered rule markers were DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4. The independent weaker Aegis shadow evaluated CVSS 2.6 and ActionableScore 1 with primitive class CLASS_C and manual review REQUIRED. Its independently reconciled impact was MODERATE. The shadow agreed with the final production impact and aggregation did not change that impact. The final reported impact is MODERATE.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline / manual review recommended (with actual score 3)	MAYBE	REMOTE SIMPLEFIX NETWORK SKB HARDWARE  DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4	-	-	checked

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

ActionableScore=3
ActionableScoreLower=2
PrimitiveClass=NONE
RealUAF=NO
HostAdminRequired=NO
NamespaceScopedPrivilege=NO
ImportantCandidate=NO
ManualReview=RECOMMENDED
AutoDowngradeAllowed=YES
RequiresHostUID0=NO
AuthorizationDecisionBypass=NO
ProtectedResourceImpact=NONE
B4PendingReview=NO
B4PendingConfirmed=NO

1. ActionableScore

* Raw base score: 2.
* Conservative score: 2; no floor or cap applied.
* Raw paranoid score: 3.
* Paranoid score: 3; no floor or cap applied.
* Final recommended bucket: **Borderline / manual review recommended**::

2. Signal breakdown

* Base +1 — firmware/device-mediated external influence: traffic for an MLO peer reaches queueing and completion, but firmware/hardware chooses the completion link.
* Base +1 — availability impact: counter drift can reach `MT_MAX_NON_AQL_PKT` and stop transmission for the affected station.
* Paranoid +1 — treat the adjacent MLO peer path as clearly network-reachable (+2 rather than the base firmware-mediated +1), consistent with the supplied AV:A assessment.
* No memory corruption: all accesses are atomic operations on valid `non_aql_packets` fields.
* No host-wide crash or strong DoS: the shown effect is station-specific transmission blocking.
* No OOB write, UAF, shared-backing write, authorization bypass, disclosure, integrity change, or privilege escalation.
* B5-R does not apply: there is an accumulated counter, but no heap/slab OOB write or later consumption of corrupted descriptors/pointers.
* No extra point for retry control: the peer can stimulate traffic, but reliable control over hardware link selection is not established.

3. Reachability analysis

An adjacent MLO peer can stimulate transmission without a local account, UID 0, capability, or namespace privilege. The mismatch nevertheless depends on hardware/firmware reporting completion through a different link WCID; attacker control and reliability of that selection remain uncertain. No prior host-admin setup beyond ordinary operation of supported mt76 MLO hardware is shown, and no timing race is required.

4. Primitive and severity reading

The defect is peer-wide accounting split incorrectly across per-link WCIDs: queueing increments one counter while completion may decrement another. This produces logical counter drift and eventually throttles the station. It is passive accounting corruption, not an OOB write or active structured-state corruption with a privileged consumer. The demonstrated impact is peer-specific wireless denial of service; stronger kernel or security-boundary effects are unsupported. Therefore `PrimitiveClass=NONE`, `ImportantCandidate=NO`, and automatic downgrade remains permissible.

5. One-sentence report phrase

An adjacent MLO peer may induce mismatched per-link non-AQL accounting that eventually blocks its station’s transmissions, without evidence of kernel memory corruption or host-wide failure.

6. Manual review advice

MANUAL CHECK RECOMMENDED

Confirm whether a peer can reliably influence link selection enough to reproduce persistent station blocking.

7. Call-site confidence

Call-site confidence: high

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

Patch: wifi: mt76: account non-AQL frames per peer rather than per link [ Upstream
Commit: 9f28f504650869d41f7b3e98e4bc4547af4d5670
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=9f28f504650869d41f7b3e98e4bc4547af4d5670

Changed files:
  drivers/net/wireless/mediatek/mt76/mt76.h
  drivers/net/wireless/mediatek/mt76/tx.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=9f28f504650869d41f7b3e98e4bc4547af4d5670

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

The original Linux kernel CVE announcement for CVE-2026-98958 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98958

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:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
  The Best / paranoid CVSS vector: AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS score: 6.5

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).