[CVE-2026-98835][MODERATE REGULAR] iio: accel: kionix-kx022a: Fix array boundary check [ Upstream

[CVE-2026-98835][MODERATE REGULAR] iio: accel: kionix-kx022a: Fix array boundary check [ Upstream

[AL-KERNEL]

CVE: CVE-2026-98835
Priority: MODERATE REGULAR
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: iio: accel: kionix-kx022a: Fix array boundary check [ Upstream
Commit: 87746be179dca4d94d73d5a323a39a87bb2e90fc
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=87746be179dca4d94d73d5a323a39a87bb2e90fc
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98835
Analysis date: Fri, 23 Oct 2026 20:32:53 -0400
ActionableScore: 2
ActionableScore lower bound: 1
Actionable bucket: Ordinary Moderate
Manual review required: NO

Summary:
An off by one ODR index check permits a one element read beyond the KX022A sampling frequency table, potentially returning incorrect or adjacent static data, but no write, crash, authorization bypass, or privilege escalation primitive is established.

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

The original Linux kernel CVE announcement for CVE-2026-98835 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98835

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-2026-98835	MODERATE	https://www.kernelcve.org/list/?q=CVE-2026-98835 CHECK WITH IMPACT FROM ORIG NN LOW | AEGIS IMPACT MODERATE AEGIS_AS=1 LEGACY=MODERATE RESULT=SAME V39_AEGIS_ONE_STEP_UP=LOW->MODERATE (final reconciliation agrees; DECISION: both MODERATE)	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N';CWE-125;CWE-193;CWE-129;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:N';BEST CVSS score: '2.5';DESCR 'An off by one boundary check in kx022a_read_raw accepts an ODR index equal to ARRAY_SIZE even though the last valid index is ARRAY_SIZE minus one. A subsequent lookup can therefore read one element beyond kx022a_accel_samp_freq_table and may return incorrect sampling frequency data or expose adjacent static data. For the CVSS the PR:L value is used for the paranoid score because a restricted local process may be able to reach the condition when sensor or bus control has been delegated. Reliable triggering normally requires influence over the hardware register value and therefore has high attack complexity. The issue is not network reachable. The demonstrated primitive is an out of bounds read with potential limited confidentiality impact. There is no supported write primitive or clear path to privilege escalation or a kernel crash. Automated impact decision path. The original SimpleNet classifier selected LOW. The primary LLM estimated paranoid CVSS 2.5 and the production ActionableScore returned 2 with recommendation Ordinary Moderate. The production rules then evaluated CVSS thresholds and ActionableScore thresholds. Recorded rule transitions were final reconciliation stage LOW to MODERATE because KP specialist did not establish a qualifying panic and the cross model evidence reconciliation rule was applied. The legacy KP specialist has no review artifact for this run. The legacy FD or DH downgrade specialist has no review artifact for this run. Exact triggered rule markers were KPANIC_UNSUPPORTED_REMOVED and V39_AEGIS_ONE_STEP_UP and MANUAL_REVIEW_REQUIRED. The independent weaker Aegis shadow evaluated CVSS 0.0 and ActionableScore 1 with primitive class CLASS_C and manual review REQUIRED. Its independently reconciled impact was MODERATE. Cross model aggregation changed the production result under an enabled evidence gated merge rule. The final reported impact is MODERATE.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 2)	MAYBE	SIMPLEFIX IMPROVEONLY LINUS KPANIC_UNSUPPORTED_REMOVED V39_AEGIS_ONE_STEP_UP MANUAL_REVIEW_REQUIRED	-	-	checked

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

ActionableScore=2
ActionableScoreLower=1
PrimitiveClass=CLASS_C
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=UNKNOWN
ImportantCandidate=NO
ManualReview=RECOMMENDED
AutoDowngradeAllowed=YES
RequiresHostUID0=UNKNOWN
AuthorizationDecisionBypass=NO
ProtectedResourceImpact=NONE
B4PendingReview=NO
B4PendingConfirmed=NO

1. ActionableScore

* Raw conservative score: 1
* Conservative score: 1
* Raw paranoid score: 2
* Paranoid score: 2
* No floor or cap was applied.
* Final recommended bucket: **Ordinary Moderate**::

2. Signal breakdown

Conservative signals:

* +1 weak corruption concern. The incorrect `>` comparison accepts an index equal to `ARRAY_SIZE`, directly implying a one-element out-of-bounds read from `kx022a_accel_samp_freq_table`.
* No privilege penalty. The complete operation needed to force the invalid register value is unresolved, so host-admin privilege is not assumed.
* No hardware penalty. The KX022A device is required, but the evidence does not establish uncommon physical attacker access as part of the trigger.

Additional paranoid signal:

* +1 plausible limited confidentiality consequence. `kx022a_read_raw()` is an IIO read path and the selected table entry is expected to influence values returned by that interface. Reading the one-past-end entry could expose adjacent static data as interpreted sampling-frequency values. The exact adjacent object and useful sensitivity are not established.

Not awarded:

* No OOB-write or memory-corruption-write points. The established operation is read-only.
* No crash or availability point. A bounded one-element static-array read does not establish a kernel fault.
* No local-unprivileged trigger point. A local reader can invoke the read path, but attacker control over the invalid hardware register value is not established.
* No remote-reachability point.
* No integrity, LPE, controlled-target, or arbitrary-read points.
* NEW52 B5-R does not apply because there is no retry-accumulated heap OOB write.
* NEW53 B3-PENDING does not apply because no shared-backing write exists.
* V33 and V34 do not apply because no active structured state is overwritten or consumed across a trust boundary.
* NEW54 B4-PENDING does not apply because no authorization decision or mandatory security guard is involved.

3. Reachability analysis

The vulnerable lookup is reached through an IIO raw-read operation, but the index originates from the accelerometer ODR register. The supplied evidence does not show that an ordinary local user can place that register into the invalid `ARRAY_SIZE` state. Such influence might require a raw bus-management interface, a delegated sensor-management service, a faulty device, or an externally controlled peripheral, but none is established here.

The complete trigger privilege is therefore unresolved. Host-admin access must not be assumed, but below-host-admin reachability is also not proven. No user-namespace or network-namespace capability path is identified. The driver and corresponding KX022A-compatible hardware must already be present. There is no network trigger and no race or timing requirement.

4. Primitive and severity interpretation

The exact primitive is a bounded one-past-end read from a static sampling-frequency table caused by an off-by-one validation error. This is neither a UAF nor an active structured-object lifetime issue. There is no repeated release, stale reference, write primitive, retry accumulation, shared-backing modification, or authorization bypass.

The demonstrated consequence is selection of data outside the intended table. Returning an incorrect sampling-frequency value is directly plausible. Limited disclosure of adjacent static data through the IIO output is technically plausible but not confirmed without the complete table layout and return path.

The issue is CLASS_C because it establishes an invalid read but not an independently useful corruption primitive. ImportantCandidate is NO because no write, protected-state modification, security-boundary crossing, or substantial disclosure is established. AutoDowngradeAllowed is YES because the remaining uncertainty concerns only whether a tightly bounded read exposes useful adjacent data.

5. One-sentence report phrase

An off by one ODR index check permits a one element read beyond the KX022A sampling frequency table, potentially returning incorrect or adjacent static data, but no write, crash, authorization bypass, or privilege escalation primitive is established.

6. Manual review recommendation

MANUAL CHECK RECOMMENDED

Verify the layout immediately following `kx022a_accel_samp_freq_table`, confirm which values are returned through IIO, and determine whether a below-host-admin actor can force the ODR register to equal `ARRAY_SIZE`.

7. Call-site confidence

Call-site confidence: medium

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

Patch: iio: accel: kionix-kx022a: Fix array boundary check [ Upstream
Commit: 87746be179dca4d94d73d5a323a39a87bb2e90fc
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=87746be179dca4d94d73d5a323a39a87bb2e90fc

Changed files:
  drivers/iio/accel/kionix-kx022a.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=87746be179dca4d94d73d5a323a39a87bb2e90fc

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

The original Linux kernel CVE announcement for CVE-2026-98835 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98835

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:N/A:N
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
  The Best / paranoid CVSS score: 2.5

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: 1
  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).