[CVE-2026-53102][LOW] wifi: mt76: Fix memory leak after mt76_connac_mcu_alloc_sta_req() [ Upstream

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

CVE: CVE-2026-53102
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: wifi: mt76: Fix memory leak after mt76_connac_mcu_alloc_sta_req() [ Upstream
Commit: eb466406d2094deefadc2cd6ddb4f6eeb086d1b4
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=eb466406d2094deefadc2cd6ddb4f6eeb086d1b4
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53102
Analysis date: Thu, 25 Jun 2026 09:18:15 -0400
ActionableScore: 2
ActionableScore lower bound: 0
Actionable bucket: Ordinary Moderate / Low-like. Autoclose candidate
Manual review required: NO

Summary:
An skb memory leak in mt76 WiFi driver error paths can occur when station or key update helpers fail before message ownership is transferred, causing possible local or service-mediated resource exhaustion but no demonstrated memory corruption or privilege escalation.

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

The original Linux kernel CVE announcement for CVE-2026-53102 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53102

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.

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

CVE-2026-53102	LOW	CHECK	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';*CWE-401;*CWE-772;**CWE-400;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.7';DESCR 'A memory leak in the mt76 WiFi driver can occur when an skb allocated by mt76_connac_mcu_alloc_sta_req() is not freed after an intermediate helper fails before mt76_mcu_skb_send_msg() takes ownership. The affected paths include station BA handling, station add, and key update flows where WED update or key TLV construction can return an error after allocation. For the CVSS the PR:L in the paranoid vector reflects environments where a local service account or delegated network manager can repeatedly trigger station or key update paths, while normal driver administration is often more privileged. The issue is not shown as directly network reachable from packet traffic alone, although WiFi association or key management events may influence related driver paths in configured deployments. Impact is denial of service through gradual memory exhaustion only. For the paranoid score, the highest still defensible interpretation is sustained local resource exhaustion without changing the class from memory leak to memory corruption.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like. Autoclose candidate (with actual score 1) 	MAYBE	REMOTE LEAK ERRORPATH UAF NETWORK SKB TEST  LOWERED_FROM_HIGH_BASED_ON_GUESSCVSS  DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5 DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3	-	-	checked

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

ActionableScore=2
ActionableScoreLower=0

## 1. ActionableScore

* Conservative score: 0
* Paranoid score: 2
* Final recommended bucket: **Ordinary Moderate / Low-like. Autoclose candidate**::

## 2. Signal breakdown

* Availability impact realistic: +1
  The bug is an skb memory leak on error paths. Sustained repeated triggering could theoretically contribute to memory pressure.

* Firmware-mediated external influence: +1
  Paranoid interpretation only. Some failing paths involve mt76 MCU/WED/device-management state, so hardware or firmware state may influence whether the leak path is hit.

* Requires admin/CAP_NET_ADMIN or trusted network-management context in typical deployments: -2 in conservative scoring
  The affected paths are station, BA, key, and driver control flows. They are normally reached through privileged WiFi management, not by arbitrary local users.

* Rare and device-specific exposure: -1 in conservative scoring
  This affects specific MediaTek mt76 WiFi driver paths and requires the relevant hardware, driver, and failing intermediate helper conditions.

* No generic memory corruption: +0
  The patch only adds dev_kfree_skb() on error paths. There is no UAF, double free, OOB write, controlled overwrite, object confusion, or page-cache corruption.

* No privilege escalation plausibility: +0
  The primitive is resource leakage only. No evidence supports LPE or sensitive data access.

## 3. Reachability analysis

The realistic trigger is local or service-mediated WiFi management activity that causes station, BA, or key update paths to allocate an skb and then fail before mt76_mcu_skb_send_msg() takes ownership. In normal deployments this requires privileged network-management control, usually root, CAP_NET_ADMIN, or a trusted daemon such as NetworkManager or hostapd. A remote WiFi peer may influence association or key-management events in some configurations, but the patch does not show a direct remote packet-to-leak primitive. Namespace or container delegation could lower practical privilege requirements if WiFi administration is exposed to a reduced-privilege service, but this is not the default threat model.

## 4. Severity interpretation

This behaves like an ordinary Moderate or Low-like resource leak, not an Important-class vulnerability. The theoretical worst case is gradual memory exhaustion if the failing path can be triggered repeatedly. There is no demonstrated memory corruption, no UAF lifetime bug, no controlled write, no confidentiality impact, and no integrity impact. The issue should not be escalated solely because it occurs in kernel networking driver code.

## 5. One-sentence report phrase

An skb memory leak in mt76 WiFi driver error paths can occur when station or key update helpers fail before message ownership is transferred, causing possible local or service-mediated resource exhaustion but no demonstrated memory corruption or privilege escalation.

## 6. Manual review recommendation

NO MANUAL CHECK NEEDED

This can be auto-closed for urgent triage purposes unless the affected product exposes untrusted users to repeated WiFi driver management operations or there is evidence that remote WiFi peers can reliably force the failing helper paths.

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

Patch: wifi: mt76: Fix memory leak after mt76_connac_mcu_alloc_sta_req() [ Upstream
Commit: eb466406d2094deefadc2cd6ddb4f6eeb086d1b4
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=eb466406d2094deefadc2cd6ddb4f6eeb086d1b4

Changed files:
  drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c
  drivers/net/wireless/mediatek/mt76/mt7915/mcu.c
  drivers/net/wireless/mediatek/mt76/mt7925/mcu.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=eb466406d2094deefadc2cd6ddb4f6eeb086d1b4

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

The original Linux kernel CVE announcement for CVE-2026-53102 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53102

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:H/UI:N/S:U/C:N/I:N/A:L
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS score: 4.7

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: 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: 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).