[CVE-2026-45868][LOW] pinctrl: single: fix refcount leak in pcs_add_gpio_func() [ Upstream

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

CVE: CVE-2026-45868
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: pinctrl: single: fix refcount leak in pcs_add_gpio_func() [ Upstream
Commit: 191bfd5710d6a7f48ba4315d8d3e908dcc15243c
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=191bfd5710d6a7f48ba4315d8d3e908dcc15243c
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-45868
Analysis date: Wed, 27 May 2026 09:19:28 -0400
ActionableScore: 0
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate / Low-like
Manual review required: NO

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-45868 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-45868

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-2026-45868	LOW	CHECK	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L';*CWE-772;*CWE-401;CWE-665;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '3.3';DESCR 'pinctrl single leaks a device_node reference in pcs_add_gpio_func because gpiospec np returned by of_parse_phandle_with_args is not released after each parsed GPIO phandle. The issue can accumulate references during device tree based GPIO function range parsing, but it is limited to probe or privileged platform configuration paths. For the CVSS the PR:L is used only for the paranoid case where a delegated device tree overlay or device management path may be available to a less privileged administrator. In typical systems PR:H is more realistic because changing the relevant hardware description or forcing repeated probe paths requires administrative control. The issue is not network reachable and has no evidence of memory corruption, information disclosure, or privilege escalation. Impact is limited availability risk from a small refcount leak.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 0)	YES	SIMPLEFIX LEAK ERRORPATH HARDWARE 	NO	NO	checked

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

ActionableScore=0

1. ActionableScore
* Conservative score: 0
* Paranoid score: 1
* Final recommended bucket: **Ordinary Moderate / Low-like**::

2. Signal breakdown
* Availability impact limited: +1 in paranoid scoring only. Repeated parsing could leak device_node references, but the leak is small and tied to probe/configuration paths.
* Requires admin/root/device configuration in typical deployments: -2. Triggering normally requires device-tree control, platform configuration, driver probe/reprobe, or overlays.
* Rare or difficult-to-reach runtime path: -1. This is a pinctrl-single device-tree parsing path, not a common user-controlled runtime API.
* No memory corruption: +0. This is a refcount/resource leak, not UAF, double-free, OOB write, or arbitrary write.
* No reliable strong DoS: +0. The patch does not show immediate system-wide exhaustion or crash.
* No confidentiality or integrity impact: +0. No data exposure, policy bypass, or privilege escalation is indicated.
* No remote reachability: +0.

3. Reachability analysis
The bug is reachable when the pinctrl-single driver parses GPIO function ranges from device tree data. In normal systems this happens during boot/probe and requires trusted platform firmware or administrator-controlled device-tree overlays to influence. Containers and user namespaces do not normally provide access to this path. It is not reachable from ordinary local user operations and not network reachable. Practical exploitation would require repeated reprobe or overlay loading, which is privileged and uncommon.

4. Severity interpretation
This behaves like a Low-like resource leak, not an actionable Moderate or Important issue. The theoretical impact is gradual reference leakage if the parsing path is repeatedly exercised. Realistic exploitation evidence is weak because the path is privileged, configuration-time, and does not provide memory corruption, sensitive data access, or a strong DoS primitive.

5. One-sentence report phrase
pinctrl-single leaked device_node references while parsing GPIO function phandles, causing a low-risk resource leak in privileged device-tree configuration paths.

6. Manual review recommendation
NO MANUAL CHECK NEEDED
This is a small refcount leak found by static analysis with no memory corruption, no remote trigger, no privilege escalation, and no practical strong DoS evidence.

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

Patch: pinctrl: single: fix refcount leak in pcs_add_gpio_func() [ Upstream
Commit: 191bfd5710d6a7f48ba4315d8d3e908dcc15243c
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=191bfd5710d6a7f48ba4315d8d3e908dcc15243c

Changed files:
  drivers/pinctrl/pinctrl-single.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=191bfd5710d6a7f48ba4315d8d3e908dcc15243c

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

The original Linux kernel CVE announcement for CVE-2026-45868 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-45868

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:L/PR:H/UI:N/S:U/C:N/I:N/A:L
  The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
  The Best / paranoid CVSS score: 3.3

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).