[CVE-2026-68197][MODERATE REGULAR] wifi: mwifiex: fix NULL dereference when the AP has HT-cap but no HT-oper

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

CVE: CVE-2026-68197
Priority: MODERATE REGULAR
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: wifi: mwifiex: fix NULL dereference when the AP has HT-cap but no HT-oper
Commit: eb42c3c8fd479166c42984728754cd779c71fd60
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=eb42c3c8fd479166c42984728754cd779c71fd60
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68197
Analysis date: Mon, 10 Aug 2026 18:30:59 -0400
ActionableScore: 3
ActionableScore lower bound: 2
Actionable bucket: Borderline network-adjacent DoS, manual check required
Manual review required: YES

Summary:
A malformed or malicious WiFi AP advertising HT Capabilities without HT Operation can cause mwifiex TDLS setup to dereference a NULL bcn_ht_oper pointer, leading to an adjacent-network kernel crash DoS.

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

The original Linux kernel CVE announcement for CVE-2026-68197 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68197

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.

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

CVE-2026-68197	MODERATE	CHECK WITH IMPACT FROM ORIG NN 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-476;*CWE-20;CWE-754;Other CVSS 'AV:A/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H';BEST CVSS score: '6.5';DESCR 'A NULL pointer dereference in the mwifiex TDLS setup path can occur because mwifiex_tdls_add_ht_oper() checks bss_desc bcn_ht_cap but dereferences bss_desc bcn_ht_oper. An AP can advertise HT Capabilities without an HT Operation element, leaving bcn_ht_oper NULL while the later TDLS path still reads ht_param from it. A nearby attacker may trigger the crash by operating or influencing a WiFi AP with this beacon shape and then causing TDLS setup while the victim uses the mwifiex driver. For the CVSS the PR:N because no account or local code execution on the victim is required, only adjacent wireless reachability and control over the relevant WiFi environment. The issue is adjacent network reachable rather than Internet reachable. Impact is denial of service via kernel crash, with no supported evidence of privilege escalation or information disclosure.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline network-adjacent DoS, manual check required (with actual score 3)	YES	REMOTE DANGER NULLPTR NETWORK KERNEL_PANIC_PLUS_UAF  DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5	NO	NO	checked

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

ActionableScore=3
ActionableScoreLower=2

## 1. ActionableScore

* Conservative score: 2
* Paranoid score: 3
* Final recommended bucket: **Borderline network-adjacent DoS, manual check required**

## 2. Signal breakdown

Conservative signals:

* Remote reachable / network-triggerable: +2
  The trigger comes from WiFi management context controlled by an associated or malicious AP. This is adjacent-network reachable, not Internet reachable.
* Reliable kernel crash / strong DoS: +1
  The vulnerable path dereferences `bss_desc->bcn_ht_oper` when it is NULL, causing a kernel crash.
* Rare AND difficult-to-reach subsystem/configuration: -1
  The issue requires the mwifiex driver, an AP advertising HT Capabilities without HT Operation, and TDLS setup.

Paranoid additional signal:

* Availability impact realistic: +1
  In a prepared adjacent WiFi environment, the crash may be repeatable when the victim associates and TDLS setup is triggered.

Not applied:

* Generic memory corruption: +0
  This is a NULL pointer dereference, not UAF, OOB write, double free, type confusion, or controlled corruption.
* Privilege escalation plausible: +0
  No reclaim, overwrite, stale callback, type confusion, or write primitive is shown.
* Confidentiality / Integrity impact: +0
  The patch supports DoS only.

Call-site confidence: high. The dereferenced pointer and the corrected guard are visible in the provided patch.

## 3. Reachability analysis

A nearby attacker may trigger the bug by operating or influencing a WiFi AP that advertises HT Capabilities but omits the HT Operation element, then causing or waiting for TDLS setup while the victim uses the mwifiex driver. No local user account on the victim is required, so PR:N is reasonable in CVSS terms. The path is not Internet reachable and depends on adjacent wireless position, mwifiex hardware or driver usage, and TDLS behavior. Containers and namespaces do not materially affect triggering because the input is external WiFi/AP state rather than a local syscall interface.

## 4. Severity interpretation

This behaves like a network-adjacent Moderate DoS rather than an Important memory-corruption vulnerability. The theoretical impact is limited by the primitive: it is a NULL dereference with no evidence of attacker-controlled object reuse, write-after-free, arbitrary write, or information disclosure. The reason it should not be automatically dismissed is that the attacker may be adjacent and unauthenticated relative to the victim host, and the result is a kernel crash.

## 5. One-sentence report phrase

A malformed or malicious WiFi AP advertising HT Capabilities without HT Operation can cause mwifiex TDLS setup to dereference a NULL bcn_ht_oper pointer, leading to an adjacent-network kernel crash DoS.

## 6. Manual review recommendation

MANUAL CHECK REQUIRED

Reason: adjacent-network reachable kernel crash, PR:N in CVSS terms, and hardware/TDLS deployment conditions need product-specific exposure validation.

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

Patch: wifi: mwifiex: fix NULL dereference when the AP has HT-cap but no HT-oper
Commit: eb42c3c8fd479166c42984728754cd779c71fd60
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=eb42c3c8fd479166c42984728754cd779c71fd60

Commit description:

mwifiex_tdls_add_ht_oper() gates its follow-the-AP-bandwidth path on
bss_desc->bcn_ht_cap being present, but then dereferences a different
pointer, bss_desc->bcn_ht_oper:

	if (ISSUPP_CHANWIDTH40(priv->adapter->hw_dot_11n_dev_cap) &&
	    bss_desc->bcn_ht_cap &&
	    ISALLOWED_CHANWIDTH40(bss_desc->bcn_ht_oper->ht_param))

bcn_ht_cap and bcn_ht_oper are populated independently while parsing the
associated AP's beacon in mwifiex_update_bss_desc_with_ie(): an AP that
advertises an HT Capabilities element but no HT Operation element leaves
bcn_ht_cap non-NULL and bcn_ht_oper NULL. Setting up a TDLS link to a
peer while associated to such an AP then dereferences the NULL
bcn_ht_oper and crashes the kernel. Every other bcn_ht_oper user in the
driver NULL-checks it first.

Guard on the pointer that is actually dereferenced.

Found by 0sec automated security-research tooling ( https://0sec.ai ).

Fixes: 396939f ("mwifiex: add HT operation IE in TDLS setup confirm")
Cc: stable@vger.kernel.org
Assisted-by: 0sec:multi-model
Signed-off-by: Doruk Tan Ozturk <doruk@0sec.ai>
Reviewed-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Link: https://patch.msgid.link/20260716103042.88469-1-doruk@0sec.ai
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/tdls.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=eb42c3c8fd479166c42984728754cd779c71fd60

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

The original Linux kernel CVE announcement for CVE-2026-68197 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-68197

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:R/S:U/C:N/I:N/A:H
  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).