[CVE-2026-98667][LOW] iio: frequency: adf4377: Fully initialize clk_init_data and clk_parent_data

[CVE-2026-98667][LOW] iio: frequency: adf4377: Fully initialize clk_init_data and clk_parent_data

[AL-KERNEL]

CVE: CVE-2026-98667
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: iio: frequency: adf4377: Fully initialize clk_init_data and clk_parent_data
Commit: 6564f394a4a95fad534643a6ca0f1d36ff081799
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6564f394a4a95fad534643a6ca0f1d36ff081799
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98667
Analysis date: Mon, 19 Oct 2026 03:43:35 -0400
ActionableScore: 0
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate
Manual review required: NO

Summary:
Incomplete initialization of ADF4377 clock parent structures can cause the clock framework to consume stale stack values as pointers and crash during device initialization, but no attacker-controlled corruption or security-boundary bypass is established.

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

The original Linux kernel CVE announcement for CVE-2026-98667 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98667

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: LOW
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-2026-98667	LOW	https://www.kernelcve.org/list/?q=CVE-2026-98667 CHECK WITH IMPACT FROM ORIG NN MODERATE | AEGIS IMPACT LOW AEGIS_AS=0 LEGACY=LOW RESULT=SAME (final reconciliation agrees; DECISION: both LOW)	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';*CWE-457;CWE-824;**CWE-476;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '4.7';DESCR 'The ADF4377 clock provider registration path uses stack allocated clk_init_data and clk_parent_data structures without fully initializing their mutually exclusive parent fields. A stale nonzero value in parent_names or another unused parent field can be interpreted as a valid pointer by the clock framework and may cause an invalid pointer dereference, kernel Oops, or panic during device initialization. The issue requires the ADF4377 driver, clock provider registration through the clock-cells property, and a stack initialization configuration or stale stack contents that expose the uninitialized fields. It is not directly network reachable. For the CVSS the PR:L value in the paranoid score reflects environments where limited local users or service accounts can trigger driver reprobe or delegated device management, while ordinary deployments generally require administrative privileges. Impact is denial of service only because no controlled write, UAF, OOB access, or information disclosure primitive is established. Automated impact decision path. The original SimpleNet classifier selected MODERATE_KPANIC. The primary LLM estimated paranoid CVSS 4.7 and the production ActionableScore returned 0 with recommendation Ordinary Moderate. The production rules then evaluated CVSS thresholds and ActionableScore thresholds. Recorded rule transitions were CVSS and initial triage stage MODERATE_KPANIC to MODERATE because the CVSS score, vector or bug class threshold rule was applied. ActionableScore thresholds stage MODERATE to LOW because the ActionableScore threshold rule was applied. final reconciliation stage LOW to LOW because KP specialist did not establish a qualifying panic. 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 DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH and DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 and KPANIC_UNSUPPORTED_REMOVED. The independent weaker Aegis shadow evaluated CVSS 1.9 and ActionableScore 0 with primitive class CLASS_C and manual review NO. Its independently reconciled impact was LOW. The shadow agreed with the final production impact and aggregation did not change that impact. The final reported impact is LOW.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 0)	MAYBE	DANGER INIT SIMPLEFIX HARDWARE LINUS DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 KPANIC_UNSUPPORTED_REMOVED	-	-	checked

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

ActionableScore=0
PrimitiveClass=CLASS_C
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=NO
ImportantCandidate=NO
ManualReview=NO
AutoDowngradeAllowed=YES
RequiresHostUID0=UNKNOWN
AuthorizationDecisionBypass=NO
ProtectedResourceImpact=NONE
B4PendingReview=NO
B4PendingConfirmed=NO

1. ActionableScore

* Raw conservative score: 0
* Conservative score: 0
* Raw paranoid score: 0
* Paranoid score: 0
* No floor or cap was applied.
* Final recommended bucket: **Ordinary Moderate**::

2. Signal breakdown

* +1 Weak or indirect corruption candidate. Uninitialized members of `clk_init_data` and `clk_parent_data` can be interpreted as pointers or other valid parent-selection data.
* +1 Potential kernel crash. The commit explicitly states that an uninitialized `parent_names` value may cause a crash during clock provider registration.
* -2 Rare hardware-only path. The vulnerable code is specific to the ADF4377 SPI frequency synthesizer and requires its clock-provider registration path.
* No UAF, OOB write, controlled overwrite, repeated release, authorization bypass, or active-state trust-boundary corruption is established.
* Controlled payload, target selection, disclosure, arbitrary write, and privilege escalation are not demonstrated.
* No additional availability point was awarded because the possible crash is the only demonstrated consequence.
* NEW52 B5-R does not apply. There is no retry-accumulated heap OOB write.
* NEW53 B3-PENDING does not apply. There is no shared-backing write.
* V33 and V34 do not apply. No attacker-influenced active structured-state write or privileged downstream consumer is established.

3. Reachability analysis

The issue occurs in `adf4377_clk_register()` when the ADF4377 device exposes the `#clock-cells` property and the driver registers a clock provider. Triggering depends on specialized physical hardware or an equivalent platform description, driver probing, and stack contents exposed by `CONFIG_INIT_STACK_ALL_PATTERN` or `CONFIG_INIT_STACK_NONE`.

No network, guest, namespace, or ordinary unprivileged interface is identified. Administrative control is commonly needed to alter the platform description, bind the driver, or force reprobe, but the supplied evidence does not prove that host-admin action is required when the affected device is already configured and probes automatically. Therefore `HostAdminRequired=UNKNOWN`. The path is not namespace scoped, and no timing race is involved.

4. Primitive and severity interpretation

The exact primitive is consumption of incompletely initialized stack structures. A stale nonzero `parent_names` value can be treated as a pointer by the clock framework, resulting in an invalid dereference. Other uninitialized `clk_parent_data` members may similarly cause incorrect parent interpretation.

This is CLASS_C invalid-state behavior with a possible kernel Oops or panic. It is not a real UAF, heap corruption, OOB write, lifetime violation, authorization bypass, or attacker-controlled active-state overwrite. The practical consequence supported by the patch is initialization-time denial of service. Stronger confidentiality, integrity, or privilege-escalation effects are unsupported.

`ImportantCandidate=NO` because no Important-preserving primitive or unresolved trust-boundary chain exists. `AutoDowngradeAllowed=YES` because the issue is hardware-specific, crash-oriented, and lacks an independently useful corruption primitive.

5. One-sentence report phrase

Incomplete initialization of ADF4377 clock parent structures can cause the clock framework to consume stale stack values as pointers and crash during device initialization, but no attacker-controlled corruption or security-boundary bypass is established.

6. Manual review recommendation

NO MANUAL CHECK NEEDED

The supplied patch establishes a specialized initialization-time invalid-pointer crash risk without UAF, OOB write, authorization bypass, cross-boundary corruption, or credible below-host-admin attack path.

7. Call-site confidence

Call-site confidence: medium

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

Patch: iio: frequency: adf4377: Fully initialize clk_init_data and clk_parent_data
Commit: 6564f394a4a95fad534643a6ca0f1d36ff081799
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6564f394a4a95fad534643a6ca0f1d36ff081799

Commit description:

The clk_init_data structure contains several mutually-exclusive members
for different methods to specify the possible parents of a clock,
prompting drivers to initialize only the members they need.  However,
not initializing all members may cause subtle issues, which are only
exposed when CONFIG_INIT_STACK_ALL_PATTERN or CONFIG_INIT_STACK_NONE is
enabled.

adf4377_clk_register() fills in init.parent_data, and assumes that
init.parent_names is NULL.  However, the latter is uninitialized, and
thus may cause a crash.

Similarly, adf4377_clk_register() fills in only parent_data.fw_name,
leaving other members of the clk_parent_data structure uninitialized.

Make sure all members are fully initialized, to fix such bugs, and to
avoid future breakage when converting drivers to a different method for
specifying the parents.

Fixes: 60e5448 ("iio: frequency: adf4377: add clk provider support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Brian Masney <bmasney@redhat.com>
Reviewed-by: Joshua Crofts <joshua.crofts1@gmail.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  drivers/iio/frequency/adf4377.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=6564f394a4a95fad534643a6ca0f1d36ff081799

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

The original Linux kernel CVE announcement for CVE-2026-98667 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98667

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:N/I:N/A:H
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS score: 4.7

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: 0

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: LOW
KPANIC detected for this report: NO
Published priority for this report (same as in Subject): LOW

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).