[CVE-2026-98971][LOW] gpio: exar: initialize the ID before registering its cleanup [ Upstream

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

CVE: CVE-2026-98971
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: gpio: exar: initialize the ID before registering its cleanup [ Upstream
Commit: bf3d841ef12fcbec4458e2750956b738b043a226
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=bf3d841ef12fcbec4458e2750956b738b043a226
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98971
Analysis date: Mon, 26 Oct 2026 21:34:30 -0400
ActionableScore: 1
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate
Manual review required: NO

Summary:
A rare probe-failure path frees another device’s IDA identifier and leaks the newly allocated identifier, causing constrained device bookkeeping corruption without demonstrated memory corruption or security-boundary impact.

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

The original Linux kernel CVE announcement for CVE-2026-98971 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98971

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.

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

CVE-2026-98971	LOW	https://www.kernelcve.org/list/?q=CVE-2026-98971 CHECK WITH IMPACT FROM ORIG NN LOW | AEGIS IMPACT LOW AEGIS_AS=2 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:L';CWE-665;CWE-404;*CWE-664;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '2.5';DESCR 'gpio_exar_probe registered an immediate cleanup action before storing the ID returned by ida_alloc in exar_gpio. If devm_add_action_or_reset failed, its reset behavior called exar_devm_ida_free with the still zero initialized index, which could release ID 0 owned by another device while leaking the actual nonzero ID. A later probe could then receive a duplicate ID 0 and cause device registration or identification problems, but there is no supported UAF, OOB access, arbitrary write, or direct confidentiality impact. For the CVSS the PR:H base value reflects that reliable triggering normally requires privileged device reprobe or hotplug control together with a rare devres allocation failure. The issue is local, has high attack complexity, and is not directly network reachable. Automated impact decision path. The original SimpleNet classifier selected LOW. The primary LLM estimated paranoid CVSS 2.5 and the production ActionableScore returned 1 with recommendation Ordinary Moderate. The production rules then evaluated CVSS thresholds and ActionableScore thresholds. No severity changing production threshold or specialist override was recorded. 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. The independent weaker Aegis shadow evaluated CVSS 0.0 and ActionableScore 2 with primitive class CLASS_C and manual review REQUIRED. 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 1)	MAYBE	SIMPLEFIX LEAK HARDWARE 	-	-	checked

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

ActionableScore=1
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 base score: 1.
* Conservative score: 1; no floor or cap applied.
* Raw paranoid score: 1.
* Paranoid score: 1; no stronger supported primitive.
* Final recommended bucket: **Ordinary Moderate**::

2. Signal breakdown

* +1 concrete persistent resource/reference leak: the allocated nonzero ID is lost when cleanup incorrectly frees index 0.
* +1 weak allocator-state corruption: `ida_free()` releases ID 0 even when it belongs to another device, permitting later duplicate allocation.
* -1 hard/unreliable trigger: the faulty immediate cleanup requires `devm_add_action_or_reset()` registration failure, normally a rare allocation-failure condition not shown attacker-controllable.
* No crash point: device registration or identification problems are plausible, but no kernel crash or host-wide DoS is established.
* No UAF, OOB access, arbitrary write, controlled payload, authorization bypass, disclosure, or protected-state integrity impact is shown.
* NEW52/B5-R does not apply: there is no retry-accumulated heap OOB write or later consumption of corrupted heap descriptors.
* B3-PENDING and B4-PENDING do not apply.

3. Reachability analysis

The vulnerable path requires probing an Exar GPIO device and failure while registering its devres cleanup action. The patch does not establish that an ordinary user, namespace-scoped capability holder, or delegated service can initiate the complete sequence or induce the required failure. Privileged reprobe/hotplug control is suggested by the supplied triage, but effective host-admin necessity is not conclusively demonstrated; therefore `HostAdminRequired=UNKNOWN`. No namespace-scoped path or remote exposure exists in the evidence.

4. Primitive and severity reading

The exact defect is allocator bookkeeping corruption: cleanup frees another device’s numeric ID while leaking the newly allocated ID. This is passive invalid-state/resource-management behavior, classified CLASS_C rather than memory corruption. Later duplicate-ID allocation may disrupt device registration or identification, but no UAF, heap overwrite, sensitive consumer, or cross-authority effect is supported. Consequently it is not an Important candidate and may be automatically downgraded.

5. One-sentence report phrase

A rare probe-failure path frees another device’s IDA identifier and leaks the newly allocated identifier, causing constrained device bookkeeping corruption without demonstrated memory corruption or security-boundary impact.

6. Manual review advice

NO MANUAL CHECK NEEDED

The patch and control flow establish only a constrained ID allocator leak/mis-release with a difficult failure prerequisite.

7. Call-site confidence

Call-site confidence: high

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

Patch: gpio: exar: initialize the ID before registering its cleanup [ Upstream
Commit: bf3d841ef12fcbec4458e2750956b738b043a226
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=bf3d841ef12fcbec4458e2750956b738b043a226

Changed files:
  drivers/gpio/gpio-exar.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=bf3d841ef12fcbec4458e2750956b738b043a226

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

The original Linux kernel CVE announcement for CVE-2026-98971 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98971

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:L
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L
  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: unknown
  Paranoid ActionableScore: 1

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).