[CVE-2026-93791][MODERATE REGULAR] wifi: iwlwifi: mvm: add a check on the tid coming from the firmware [ Upstream

[CVE-2026-93791][MODERATE REGULAR] wifi: iwlwifi: mvm: add a check on the tid coming from the firmware [ Upstream

[AL-KERNEL]

CVE: CVE-2026-93791
Priority: MODERATE REGULAR
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: wifi: iwlwifi: mvm: add a check on the tid coming from the firmware [ Upstream
Commit: 0b5325a0771674f1d65618de7db3df9d49186a12
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=0b5325a0771674f1d65618de7db3df9d49186a12
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-93791
Analysis date: Thu, 24 Sep 2026 20:20:41 -0400
ActionableScore: 2
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate
Manual review required: NO

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-93791 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-93791

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-2026-93791	MODERATE	https://www.kernelcve.org/list/?q=CVE-2026-93791 CHECK WITH IMPACT FROM ORIG NN MODERATE	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H';CWE-129;CWE-125;*CWE-787;*CWE-20;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:H';BEST CVSS score: '6.4';DESCR 'An unchecked firmware supplied TID value in an iwlwifi BA notification is used as an index into mvmsta tid_data. A malformed value can access memory outside the tid_data array in kernel context and may cause a kernel crash or limited confidentiality and integrity impact depending on the adjacent object layout and later accesses. For the CVSS the PR:N in the paranoid score assumes an adjacent attacker can cause the WiFi firmware to generate a malformed BA notification without local access. This remote adjacent path is not proven by the patch and requires manual verification of firmware notification parsing and TID derivation. The base score uses PR:H because the directly supported trigger requires compromised or replaced firmware which is normally an administrative capability. The issue is not demonstrated as Internet reachable. Impact is at least a local denial of service and potential out of bounds kernel memory access. YES REQUIRES MANUAL CHECK';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 2)	YES	REMOTE OOB SIMPLEFIX NETWORK  DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4	NO	NO	checked

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

ActionableScore=2
PrimitiveClass=CLASS_C
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=UNKNOWN
ImportantCandidate=NO
ManualReview=RECOMMENDED
AutoDowngradeAllowed=YES

1. ActionableScore

* Raw conservative score: 2
* Conservative score: 2
* Raw paranoid score: 2
* Paranoid score: 2
* Final recommended bucket: **Ordinary Moderate**::

No floor or cap was applied.

2. Signal breakdown

* +1 Weak indirect corruption candidate. The firmware supplied u8 TID is used as an unchecked index into mvmsta->tid_data before the added bounds check. This establishes an out of bounds array access candidate in kernel context.
* +1 Broadly exercised driver path. iwlwifi BA notifications and per TID transmission state are normal runtime functionality on affected Intel WiFi devices using aggregation.

Non-awarded signals:

* No concrete out of bounds write is demonstrated by the supplied diff. The visible patch proves that an out of range array index was possible, but the subsequent tid_data field accesses are not included.
* No controlled attacker payload or target selection is demonstrated.
* No kernel crash, panic, information disclosure, integrity impact, privilege escalation, or arbitrary read or write is demonstrated.
* Remote or WiFi adjacent reachability is not established. The value is firmware controlled, but the supplied evidence does not show that an over the air attacker can cause firmware to emit an invalid TID.
* Firmware mediated external influence is not awarded because external influence over ba_notif->tid is not established.
* No UAF, stale object use, repeated release, refcount mutation, callback control, or object replacement exists in the supplied evidence.
* No privilege penalty is applied. Host admin privilege may be needed to replace firmware, but that prerequisite is not proven as the only way to trigger the invalid notification.

Relevant CWE candidates are CWE-129 Improper Validation of Array Index, CWE-125 Out of Bounds Read, and potentially CWE-787 Out of Bounds Write only if later unseen tid_data accesses modify fields through the invalid pointer.

3. Reachability analysis

The vulnerable input is received from Intel WiFi firmware through a BA notification. The patch does not show that a remote WiFi peer can directly control the firmware notification TID value. Normal IEEE 802.11 TID values are normally range limited, so a malformed value may instead require faulty, compromised, or otherwise unexpected firmware behavior.

The evaluated attacker model is unresolved. A host administrator may be able to replace or manipulate firmware, but the supplied material does not establish that this is required for every trigger. Conversely, it does not establish that an ordinary local user or adjacent wireless attacker can trigger the complete path.

No relevant namespace capability chain is shown. Namespace scoped privilege is therefore UNKNOWN. There is no demonstrated prior host setup requirement beyond use of an affected Intel iwlwifi device and normal BA notification handling.

4. Primitive and severity interpretation

The exact established primitive is an unchecked firmware supplied array index. An invalid TID can select memory outside the mvmsta->tid_data array before the new bounds check rejects it. This is not a UAF and does not involve a lifetime violation.

The patch is a validation fix and the supplied context does not show the later use of the indexed tid_data element. Therefore, the available evidence supports an invalid access or crash concern, but not a controlled overwrite, disclosure path, controlled type confusion, or privilege escalation primitive.

This is CLASS_C because the established behavior is an invalid state and potential out of bounds access without independently useful exploitation leverage. ImportantCandidate is NO because neither a strong corruption primitive nor meaningful attacker-controlled reuse or write leverage is demonstrated. AutoDowngradeAllowed is YES because the available evidence supports a constrained invalid-access concern and does not leave a concrete unresolved lifetime, ownership, authorization, or controlled-corruption primitive.

Likely operational severity is ordinary Moderate or lower. The issue should still be reviewed against the complete iwl_mvm_rx_ba_notif function because a later write through tid_data would materially change the primitive classification.

5. One-sentence report phrase

An unchecked firmware supplied TID value can index outside the iwlwifi tid_data array, potentially causing an invalid kernel memory access, but remote WiFi attacker control and a controlled out of bounds write are not established by the supplied patch.

6. Manual review recommendation

MANUAL CHECK RECOMMENDED

Review the complete iwl_mvm_rx_ba_notif function and firmware notification origin to determine whether the invalid tid_data pointer is later written through and whether malformed BA notifications can be induced by adjacent WiFi traffic rather than requiring compromised firmware.

7. Call-site confidence

Call-site confidence: low

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

Patch: wifi: iwlwifi: mvm: add a check on the tid coming from the firmware [ Upstream
Commit: 0b5325a0771674f1d65618de7db3df9d49186a12
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=0b5325a0771674f1d65618de7db3df9d49186a12

Changed files:
  drivers/net/wireless/intel/iwlwifi/mvm/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=0b5325a0771674f1d65618de7db3df9d49186a12

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

The original Linux kernel CVE announcement for CVE-2026-93791 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-93791

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:L/I:L/A:H
  The Best / paranoid CVSS vector: AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H
  The Best / paranoid CVSS score: 6.4

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: 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).