[CVE-2026-53318][MODERATE REGULAR] wifi: mt76: mt7925: prevent NULL pointer dereference in mt7925_tx_check_aggr() [ Upstream

[CVE-2026-53318][MODERATE REGULAR] wifi: mt76: mt7925: prevent NULL pointer dereference in mt7925_tx_check_aggr() [ Upstream

[AL-KERNEL]

CVE: CVE-2026-53318
Priority: MODERATE REGULAR
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: wifi: mt76: mt7925: prevent NULL pointer dereference in mt7925_tx_check_aggr() [ Upstream
Commit: 28ed0b61f67386c0ba1213227d350005000240fd
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=28ed0b61f67386c0ba1213227d350005000240fd
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53318
Analysis date: Fri, 26 Jun 2026 16:36:22 -0400
ActionableScore: 2
ActionableScore lower bound: 1
Actionable bucket: Ordinary Moderate / manual reachability check recommended
Manual review required: NO

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-53318 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53318

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: NO

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

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

CVE-2026-53318	MODERATE	CHECK	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H';**CWE-476;CWE-754;CWE-703;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '5.3';DESCR 'mt7925_tx_check_aggr dereferenced sta before checking whether sta was NULL, so a specific TX aggregation path in the mt7925 WiFi driver could crash the kernel. The practical trigger likely depends on mt7925 hardware, active WiFi traffic, and a station or wcid state where sta is missing while an skb is still processed. For the CVSS the PR:N is used only in the paranoid adjacent network interpretation, where a nearby WiFi peer or AP may be able to influence association or traffic state without a local account on the victim. The base case is local PR:L because reliable triggering more likely requires a local user or process that can send traffic through the affected interface. Impact is denial of service via kernel crash. No concrete UAF, OOB access, information leak, or privilege escalation primitive is shown by the code change.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / manual reachability check recommended (with actual score 2)	YES	REMOTE DANGER NULLPTR SIMPLEFIX NETWORK KERNEL_PANIC_PLUS_UAF  DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH	YES	NO	checked

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

ActionableScore=2
ActionableScoreLower=1

1. ActionableScore
* Conservative score: 1
* Paranoid score: 2
* Final recommended bucket: **Ordinary Moderate / manual reachability check recommended**

2. Signal breakdown
* Local unprivileged trigger: +1. A local user or process may be able to generate TX traffic through the affected mt7925 WiFi interface, but reliable triggering likely depends on driver state.
* Firmware-mediated or adjacent external influence: +1 in paranoid scoring only. A nearby AP or WiFi peer may influence association or traffic state, but the patch does not prove a direct remote packet trigger.
* Reliable kernel crash / strong DoS: +1. The bug is a NULL pointer dereference before checking `sta`, which can crash the kernel.
* Hard or unreliable state required: -1. Triggering appears to require a specific TX aggregation path where `sta` is NULL while an skb is still processed.
* No memory corruption bonus. The patch shows NULL dereference, not UAF, OOB write, double free, type confusion, or attacker-controlled overwrite.
* No LPE bonus. There is no concrete privilege escalation primitive.
* No C/I impact. The visible impact is availability only.

3. Reachability analysis
A conservative trigger requires local ability to use the affected mt7925 wireless interface and generate traffic that reaches `mt7925_tx_check_aggr()`. A paranoid interpretation allows adjacent wireless influence because WiFi association and peer state can be affected by nearby APs or peers, but the diff does not show a clear packet-to-crash path. Namespaces do not materially lower the requirement unless an untrusted user can access or control the physical WiFi interface. The path is hardware-specific to MediaTek mt7925 and is not a common networking core path.

4. Severity interpretation
This behaves like an ordinary Moderate DoS issue rather than an Important-class vulnerability. Theoretical impact is kernel crash through NULL pointer dereference. Realistic exploitation evidence does not show memory corruption, privilege escalation, information disclosure, or integrity impact. The main uncertainty is whether the bug can be triggered by an adjacent WiFi attacker without local access.

5. One-sentence report phrase
A NULL pointer dereference in `mt7925_tx_check_aggr()` can crash systems using the mt7925 WiFi driver when a specific TX aggregation path dereferences `sta` before validating it, with no demonstrated confidentiality, integrity, or privilege escalation impact.

6. Manual review recommendation
MANUAL CHECK RECOMMENDED. Confirm whether `sta == NULL` can be reached only from local traffic and teardown paths, or whether an adjacent WiFi AP or peer can reliably trigger the crash remotely.

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

Patch: wifi: mt76: mt7925: prevent NULL pointer dereference in mt7925_tx_check_aggr() [ Upstream
Commit: 28ed0b61f67386c0ba1213227d350005000240fd
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=28ed0b61f67386c0ba1213227d350005000240fd

Changed files:
  drivers/net/wireless/mediatek/mt76/mt7925/mac.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=28ed0b61f67386c0ba1213227d350005000240fd

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

The original Linux kernel CVE announcement for CVE-2026-53318 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53318

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:H
  The Best / paranoid CVSS vector: AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS score: 5.3

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: 1
  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).