[CVE-2026-98830][MODERATE 7.0] wifi: wfx: validate MIB read length before copying to caller [ Upstream

[CVE-2026-98830][MODERATE 7.0] wifi: wfx: validate MIB read length before copying to caller [ Upstream

[AL-KERNEL]

CVE: CVE-2026-98830
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: wifi: wfx: validate MIB read length before copying to caller [ Upstream
Commit: 02886c18a340da59df57365f29009e1258bfe333
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=02886c18a340da59df57365f29009e1258bfe333
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98830
Analysis date: Mon, 19 Oct 2026 05:33:54 -0400
ActionableScore: 4
ActionableScore lower bound: unknown
Actionable bucket: Actionable Moderate / Strong Important candidate requiring manual review
Manual review required: YES

Summary:
A firmware-controlled MIB reply length can drive an out-of-bounds memcpy into a caller-provided kernel buffer, causing kernel memory corruption and a possible crash, while direct network reachability and privilege-escalation leverage remain unresolved.

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

The original Linux kernel CVE announcement for CVE-2026-98830 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98830

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 7.0
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-2026-98830	MODERATE	https://www.kernelcve.org/list/?q=CVE-2026-98830 CHECK WITH IMPACT FROM ORIG NN MODERATE | AEGIS IMPACT MODERATE_KPANIC AEGIS_AS=2 LEGACY=MODERATE_KPANIC RESULT=SAME V39_AEGIS_ONE_STEP_UP=MODERATE->MODERATE_KPANIC (final reconciliation agrees; DECISION: both MODERATE_KPANIC)	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H';CWE-120;CWE-125;*CWE-787;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:H/A:H';BEST CVSS score: '7';DESCR 'wfx_hif_read_mib trusts the length supplied in a firmware MIB response and passes it to memcpy without verifying that it fits in the caller provided buffer. An oversized response therefore causes both an out of bounds read from the reply allocation and an out of bounds write into adjacent kernel memory. The immediate impact can include kernel memory corruption and a system crash. Depending on the affected caller buffer and adjacent objects, information disclosure or privilege escalation may also be possible, but reliable control of the corrupted data is not established. For the CVSS the PR:L in the paranoid score represents environments where a local service account, container root, or user with delegated wireless administration can reach the relevant driver operations. Typical systems may instead require PR:H to manage the interface or install modified firmware. The issue is not proven to be directly network reachable because ordinary WiFi peers do not normally control firmware generated MIB confirmation lengths. A malicious or compromised device firmware is the clearest supported trigger condition. Automated impact decision path. The original SimpleNet classifier selected MODERATE_KPANIC. The primary LLM estimated paranoid CVSS 7 and the production ActionableScore returned 4 with recommendation Actionable Moderate / Strong Important candidate requiring manual review. The production rules then evaluated CVSS thresholds and ActionableScore thresholds. Recorded rule transitions were KP and FD specialist checks stage MODERATE_KPANIC to MODERATE because KP specialist did not establish a qualifying panic. final reconciliation stage MODERATE to MODERATE_KPANIC because the cross model evidence reconciliation rule was applied. The legacy KP specialist produced a review artifact and its decision was processed by the applicable KP rules. The legacy FD or DH downgrade specialist has no review artifact for this run. Exact triggered rule markers were DECREASED_TO_MODERATEREG_BASED_ON_FALSEPOSCHECKOFKP and V39_AEGIS_ONE_STEP_UP and MANUAL_REVIEW_REQUIRED. The independent weaker Aegis shadow evaluated CVSS 0.0 and ActionableScore 2 with primitive class CLASS_B and manual review REQUIRED. Its independently reconciled impact was MODERATE_KPANIC. Cross model aggregation changed the production result under an enabled evidence gated merge rule. The final reported impact is MODERATE_KPANIC.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate / Strong Important candidate requiring manual review (with actual score 4)	MAYBE	REMOTE NOMEMCHK SIMPLEFIX NETWORK  DECREASED_TO_MODERATEREG_BASED_ON_FALSEPOSCHECKOFKP KPANIC V39_AEGIS_ONE_STEP_UP MANUAL_REVIEW_REQUIRED	-	-	checked

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

ActionableScore=4
PrimitiveClass=CLASS_A
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=UNKNOWN
ImportantCandidate=YES
ManualReview=REQUIRED
AutoDowngradeAllowed=NO
RequiresHostUID0=UNKNOWN
AuthorizationDecisionBypass=NO
ProtectedResourceImpact=NONE
B4PendingReview=NO
B4PendingConfirmed=NO

1. ActionableScore

* Raw conservative score: 4
* Conservative score: 4
* Raw paranoid score: 4
* Paranoid score: 4
* No floor or cap was applied.
* Final recommended bucket: **Actionable Moderate / Strong Important candidate requiring manual review**::

2. Signal breakdown

* +2 Strong corruption primitive. Firmware controls `reply->length`, which becomes the length of a confirmed out-of-bounds `memcpy()` into a caller-provided kernel buffer. The overwrite extent is firmware-influenced, although the destination and all copied bytes are not necessarily controllable.
* +1 Firmware-mediated external influence. The malformed length originates in a device firmware response. This is not equivalent to direct network reachability.
* +1 Realistic kernel crash or strong DoS. A variable-length overwrite of an unknown caller buffer can corrupt adjacent kernel memory or fault during the source over-read.
* No additional point for the source OOB read because no disclosure path is established.
* No confidentiality or integrity consequence point beyond the corruption primitive. No protected victim, read-back path, credential target, or persistent policy modification is identified.
* No arbitrary or directed write is established.
* No controlled reclaim, callback influence, privilege escalation, or practical exploit chain is demonstrated.
* No retry-accumulated B5-R signal applies. The patch shows one unchecked copy, not an index or offset accumulated across retries.
* V33 active-state consumption is unresolved. The supplied context does not identify the concrete caller-buffer type, overwritten field, or privileged downstream consumer.
* B3-PENDING does not apply because shared or file-backed storage is not involved.
* B4-PENDING does not apply because this is bounds corruption, not an authorization decision bypass.
* No hardware rarity penalty was applied merely because the defect is in a WiFi driver.

3. Reachability analysis

The vulnerable operation processes a MIB reply generated by WFX firmware. A malicious or compromised firmware can influence `reply->length` and potentially part of the copied data, but ordinary WiFi traffic is not shown to control this confirmation field directly.

The complete attacker path is unresolved. Installing modified firmware may require host-administrator authority, but the supplied evidence does not prove that modified firmware installation is the only trigger. Conversely, it does not establish that an ordinary local user, delegated network administrator, container, or wireless peer can induce the malformed response.

The relevant operation is tied to supported WFX hardware and active driver use. This is a hardware prerequisite, but the evidence does not justify treating it as physical-only or applying a rare-hardware penalty. No race or retry timing is required by the demonstrated copy defect.

4. Primitive and severity interpretation

The exact primitive is a firmware-length-controlled heap or kernel-buffer out-of-bounds write accompanied by an out-of-bounds read from the reply allocation. It is not a UAF, double release, authorization bypass, or retry-accumulated overwrite.

The destination is a caller-provided buffer whose allocation class and adjacent objects are not visible. The demonstrated behavior is broader than an invalid read because `memcpy()` actively writes beyond `val_len`. This supports CLASS_A as an attacker-influenced OOB-write primitive, but it does not establish an arbitrary target, fully controlled payload, LPE, or remote attack.

The demonstrated consequences are kernel memory corruption and plausible kernel crash. Information disclosure and privilege escalation remain hypotheses requiring caller and layout analysis. ImportantCandidate is YES because a concrete variable-length kernel OOB write should not be automatically reduced to a crash-only bug before its callers and overwritten objects are examined. AutoDowngradeAllowed is NO for the same reason.

5. One-sentence report phrase

A firmware-controlled MIB reply length can drive an out-of-bounds memcpy into a caller-provided kernel buffer, causing kernel memory corruption and a possible crash, while direct network reachability and privilege-escalation leverage remain unresolved.

6. Manual review recommendation

MANUAL CHECK REQUIRED

Inspect every `wfx_hif_read_mib()` caller, the allocation and lifetime of each `val` buffer, the reply-allocation size, firmware message validation, and whether an untrusted local or wireless actor can induce malformed MIB confirmations.

7. Call-site confidence

Call-site confidence: medium

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

Patch: wifi: wfx: validate MIB read length before copying to caller [ Upstream
Commit: 02886c18a340da59df57365f29009e1258bfe333
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=02886c18a340da59df57365f29009e1258bfe333

Changed files:
  drivers/net/wireless/silabs/wfx/hif_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=02886c18a340da59df57365f29009e1258bfe333

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

The original Linux kernel CVE announcement for CVE-2026-98830 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98830

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:H/A:H
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
  The Best / paranoid CVSS score: 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: unknown
  Paranoid ActionableScore: 4

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: YES
Published priority for this report (same as in Subject): MODERATE 7.0

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).