[CVE-2026-98185][MODERATE REGULAR] wifi: mwifiex: validate scan response extents

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

CVE: CVE-2026-98185
Priority: MODERATE REGULAR
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: wifi: mwifiex: validate scan response extents
Commit: 25217c5f6ce0bf3004f80c129464cd35fe9a420f
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=25217c5f6ce0bf3004f80c129464cd35fe9a420f
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98185
Analysis date: Thu, 08 Oct 2026 10:57:32 -0400
ActionableScore: 2
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate
Manual review required: NO

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-98185 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98185

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.

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

CVE-2026-98185	MODERATE	https://www.kernelcve.org/list/?q=CVE-2026-98185 CHECK WITH IMPACT FROM ORIG NN MODERATE | AEGIS IMPACT MODERATE_KPANIC AEGIS_AS=2 LEGACY=MODERATE RESULT=DIFF (legacy and Aegis reconciliation differ; DECISION: legacy MODERATE vs Aegis MODERATE_KPANIC)	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:N/A:H';CWE-125;CWE-191;*CWE-20;Other CVSS 'AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '5.9';DESCR 'An out of bounds read can occur in the mwifiex WiFi scan response path because the driver derives the TLV buffer length by subtracting fixed response fields and firmware supplied BSS data length without validating that both extents fit inside resp size. A short scan response or an oversized BSS length can underflow the calculated length and make the TLV parser read beyond the command response. For the CVSS the PR:N because an attacker does not need local access if malformed wireless scan data can be propagated by the affected firmware. The attack vector is adjacent wireless access rather than general Internet access. Reliable triggering depends on firmware behavior and may require a crafted beacon or probe response during scanning. Impact is at least denial of service through an invalid kernel memory read. The paranoid score includes limited confidentiality impact because an out of bounds read exists, but the patch does not establish an out of bounds write, privilege escalation, or a proven information disclosure path.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 2)	MAYBE	REMOTE OOB SIMPLEFIX NETWORK  DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4	-	-	checked

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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 Firmware-mediated external influence. The vulnerable response fields, including BSS descriptor length, originate from the WiFi firmware scan-response path. This is not direct remote network reachability because firmware mediation is material.
* +1 Weak invalid-read concern. An unchecked subtraction can underflow tlv_buf_size and permit the TLV parser to walk beyond the logical command response extent.

Important non-awarded signals:

* No real UAF, stale object, refcount misuse, repeated release, or lifetime mutation is established.
* No out-of-bounds write, controlled overwrite, controlled reclaim, type confusion, or arbitrary kernel read/write is demonstrated.
* No kernel crash is directly demonstrated by the patch. The stated consequence is parser traversal beyond the command response, which may result in a fault or invalid parsing but does not prove a reliable host crash.
* No confidentiality point is awarded. The patch establishes an invalid read path but does not establish copying of out-of-bounds bytes to userspace, the network, firmware, or another observable output.
* No integrity point is awarded. No attacker-controlled write or security-relevant state modification is shown.
* No direct remote reachability point is awarded. A nearby WiFi attacker may only influence the vulnerable path if the particular mwifiex firmware converts malformed beacon or probe-response data into a malformed scan response.
* No local unprivileged trigger point is awarded. The supplied context does not prove that an ordinary local user can force scanning and reach the complete vulnerable firmware-response sequence.
* No reliable kernel crash or separate availability point is awarded because neither is established independently.

3. Reachability analysis

The immediate input is a firmware command response consumed by the mwifiex driver. The commit identifies a firmware-provided BSS length and a malformed or short scan response as the prerequisite.

A potentially relevant attacker model is an adjacent WiFi attacker transmitting malformed beacon or probe-response frames while the device is scanning. However, the complete chain is unresolved because the supplied patch does not establish that affected Marvell firmware propagates attacker-controlled management-frame lengths into the malformed command response fields required by the bug.

This is not a direct Internet-reachable network path. Firmware processing is an essential mediation layer. No host administrator privilege is proven necessary, but below-host-admin reachability is also not proven for the complete trigger. Therefore HostAdminRequired and NamespaceScopedPrivilege are UNKNOWN.

No namespace-specific capability check, sysctl prerequisite, boot option, special device provisioning, or attacker-controlled object-lifetime sequence is visible in the supplied context. The issue requires affected mwifiex hardware and firmware, but hardware specificity alone is not scored as a rare-hardware penalty.

4. Primitive and severity interpretation

The patch fixes an integer-underflow-driven out-of-bounds parsing condition. A short response or oversized BSS descriptor length can make tlv_buf_size wrap, causing the TLV parser to inspect data beyond the declared command-response extent.

This is not a UAF and does not involve active structured stale-object reuse, cleanup lifetime handling, object replacement, refcount mutation, or a second release operation. The established primitive is an invalid read or invalid parser extent, with no demonstrated disclosure or write primitive.

The appropriate classification is CLASS_C because the established behavior is invalid-state parsing and possible crash or driver malfunction without an independently useful corruption primitive. The issue may be operationally relevant for affected wireless devices, but the available evidence does not support Important classification, privilege escalation, or a strong memory-corruption conclusion.

ImportantCandidate is NO because meaningful exploitation leverage beyond invalid parsing and possible denial of service is not established. AutoDowngradeAllowed is YES because there is no demonstrated UAF, controlled corruption, authorization bypass, ownership violation, or unresolved repeated lifetime mutation.

5. One-sentence report phrase

An unchecked scan-response length calculation in the mwifiex driver can underflow the TLV parsing extent and cause parsing beyond the declared firmware response, with possible driver failure or denial of service if malformed scan data reaches the affected firmware path.

6. Manual review recommendation

MANUAL CHECK RECOMMENDED

Verify the affected mwifiex firmware behavior and the downstream TLV parser to determine whether malformed nearby WiFi management frames can produce the required malformed firmware response and whether parsing exceeds the actual allocation rather than only the logical response length.

7. Call-site confidence

Call-site confidence: medium

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

Patch: wifi: mwifiex: validate scan response extents
Commit: 25217c5f6ce0bf3004f80c129464cd35fe9a420f
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=25217c5f6ce0bf3004f80c129464cd35fe9a420f

Commit description:

mwifiex_ret_802_11_scan() subtracts the fixed response fields and the
firmware-provided BSS length from resp->size without first proving that
either extent fits. A short response or oversized BSS length can
therefore underflow tlv_buf_size and make the TLV parser walk beyond the
command response.

Compute the fixed extent from the selected normal or background scan
response. Validate that the fixed fields and BSS data fit before deriving
the TLV extent and entering the parser.

Fixes: 5e6e3a9 ("wireless: mwifiex: initial commit for Marvell mwifiex driver")
Cc: stable@vger.kernel.org
Assisted-by: Codex:gpt-5
Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
Link: https://patch.msgid.link/20260815135227.50392-1-pengpeng@iscas.ac.cn
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  drivers/net/wireless/marvell/mwifiex/scan.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=25217c5f6ce0bf3004f80c129464cd35fe9a420f

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

The original Linux kernel CVE announcement for CVE-2026-98185 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98185

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:H
  The Best / paranoid CVSS vector: AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H
  The Best / paranoid CVSS score: 5.9

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).