[CVE-2026-72314][LOW] regulator: core: regulator_lock_two() should test for EDEADLK not EDEADLOCK [ Upstream

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

CVE: CVE-2026-72314
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: regulator: core: regulator_lock_two() should test for EDEADLK not EDEADLOCK [ Upstream
Commit: dc804f390fddd9c389edf0976356942e16878d8f
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=dc804f390fddd9c389edf0976356942e16878d8f
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72314
Analysis date: Sat, 15 Aug 2026 21:57:00 -0400
ActionableScore: 1
ActionableScore lower bound: 0
Actionable bucket: Ordinary Moderate / Low-like
Manual review required: NO

Summary:
A regulator core logic bug compares ww_mutex_lock() backoff against EDEADLOCK instead of EDEADLK, which can break lock retry handling on MIPS and may cause regulator lock imbalance or local denial of service under contention.

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

The original Linux kernel CVE announcement for CVE-2026-72314 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72314

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
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CVE-2026-72314	LOW	CHECK WITH IMPACT FROM ORIG NN 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-754;CWE-667;CWE-703;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '4.7';DESCR 'A logic error in regulator_lock_two() compares the ww_mutex_lock() backoff return value against EDEADLOCK instead of EDEADLK. On architectures where these constants differ, mainly practical for MIPS in this subsystem, a real deadlock backoff can be treated as an unexpected error and the function may return with only one regulator lock held. This can cause lock imbalance, deadlock, WARN paths, or system availability loss in regulator control paths. For the CVSS the PR:L is used for the paranoid interpretation because some systems may expose regulator related operations indirectly to local low privilege workloads, but reliable triggering usually depends on kernel driver activity and architecture specific contention. The issue is not network reachable. Impact is denial of service only because the patch context supports a locking failure rather than memory corruption or privilege escalation.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 1)	YES	LOCK DEADLOCK WARNONLY HARDWARE TEST 	YES	NO	checked

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ACTIONABLESCORE ANALYSIS
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ActionableScore=1
ActionableScoreLower=0

## 1. ActionableScore

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

## 2. Signal breakdown

Triggered signals:

* Reliable kernel crash / strong DoS: +1 in paranoid scoring only. The wrong EDEADLOCK check can cause lock imbalance or deadlock in regulator paths, but the patch does not show a direct panic, UAF, OOB access, or controlled corruption primitive.
* Availability impact realistic: +1 is not separately counted because the DoS signal already covers the same availability consequence.
* Requires admin/root/CAP_* in typical deployments: -2 conservative. Reliable triggering normally depends on regulator control paths, driver activity, device power-management flows, or privileged kernel/device-management operations.
* Hard or unreliable race / special timing required: -1. The issue requires ww_mutex contention and the specific backoff path.
* Rare AND difficult-to-reach subsystem/configuration: -1. The bug is practically relevant mainly on MIPS because EDEADLK and EDEADLOCK differ there and regulator core relevance is limited for the other affected architectures.

Not triggered:

* No remote/network reachability.
* No firmware-mediated external influence shown.
* No generic memory corruption.
* No UAF, double-free, OOB write, arbitrary write, refcount takeover, or stale callback.
* No plausible privilege escalation primitive.
* No confidentiality or integrity impact supported.

## 3. Reachability analysis

The bug is reachable only when regulator_lock_two() hits a ww_mutex deadlock backoff path on an architecture where EDEADLK and EDEADLOCK differ. In practice the commit identifies MIPS as the relevant platform. Typical triggering requires kernel regulator operations and contention, usually driven by driver or power-management activity rather than a normal unprivileged user API.

Namespaces and containers do not meaningfully lower the privilege requirement in the usual case, because regulator control is not normally exposed as an unprivileged namespaced interface. A paranoid interpretation can consider indirect local workload influence over device activity, but reliable exploitation remains timing-dependent and platform-specific.

## 4. Severity interpretation

This behaves like an ordinary Moderate or Low-like kernel correctness bug with possible local DoS impact. The realistic consequence is lock imbalance, WARN path, deadlock, or availability loss in regulator control paths.

There is no supported memory corruption primitive. Theoretical impact beyond DoS is not justified by the patch because the failure mode is an incorrect error-code comparison in lock retry handling, not object lifetime corruption or attacker-controlled memory modification.

## 5. One-sentence report phrase

A regulator core logic bug compares ww_mutex_lock() backoff against EDEADLOCK instead of EDEADLK, which can break lock retry handling on MIPS and may cause regulator lock imbalance or local denial of service under contention.

## 6. Manual review recommendation

NO MANUAL CHECK NEEDED

This is platform-specific, timing-dependent, not network reachable, and the patch supports DoS-only impact without memory corruption or privilege escalation evidence.

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

Patch: regulator: core: regulator_lock_two() should test for EDEADLK not EDEADLOCK [ Upstream
Commit: dc804f390fddd9c389edf0976356942e16878d8f
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=dc804f390fddd9c389edf0976356942e16878d8f

Changed files:
  drivers/regulator/core.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=dc804f390fddd9c389edf0976356942e16878d8f

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

The original Linux kernel CVE announcement for CVE-2026-72314 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72314

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: 0
  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).