[CVE-2026-99021][MODERATE 7.0] regulator: of: fill in supply names in of_regulator_bulk_get_all() [ Upstream

[CVE-2026-99021][MODERATE 7.0] regulator: of: fill in supply names in of_regulator_bulk_get_all() [ Upstream

[AL-KERNEL]

CVE: CVE-2026-99021
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: regulator: of: fill in supply names in of_regulator_bulk_get_all() [ Upstream
Commit: 82ac8c4939bdbd064b4f54a580fbe4baf0d60e41
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=82ac8c4939bdbd064b4f54a580fbe4baf0d60e41
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-99021
Analysis date: Tue, 27 Oct 2026 03:29:59 -0400
ActionableScore: 5
ActionableScore lower bound: unknown
Actionable bucket: Actionable Moderate / Strong Important candidate requiring manual review
Manual review required: YES

Summary:
An unbounded Device Tree supply-name copy causes a concrete stack OOB write, while an uninitialized supply pointer is separately consumed during regulator enable failure reporting.

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

The original Linux kernel CVE announcement for CVE-2026-99021 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-99021

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 7.0
Manual review required: YES

A detailed explanation of the methodology and priority rules is included
at the end of this message.

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

CVE-2026-99021	MODERATE	https://www.kernelcve.org/list/?q=CVE-2026-99021 CHECK WITH IMPACT FROM ORIG NN LOW | AEGIS IMPACT MODERATE_KPANIC AEGIS_AS=3 LEGACY=MODERATE_KPANIC RESULT=SAME (final reconciliation agrees; DECISION: both MODERATE_KPANIC)	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H';*CWE-457;CWE-824;CWE-121;*CWE-20;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:H';BEST CVSS score: '7';DESCR 'of_regulator_bulk_get_all left each supply pointer uninitialized while regulator_bulk_enable could later print that pointer after an enable failure. This provides an invalid string read that may cause a kernel crash and could expose kernel memory through logs when the pointer happens to reference readable data. The same function copied an attacker influenced Device Tree property prefix into a fixed 64 byte stack buffer lacking a length bound and therefore also contained a concrete stack out of bounds write. For the CVSS the PR:H base value reflects that reliable exploitation normally requires control of Device Tree data or an OF overlay. The paranoid PR:L value covers a delegated firmware or Device Tree management service with reduced administrative capability. The issue is local and is not directly reachable through ordinary network traffic. Automated impact decision path. The original SimpleNet classifier selected LOW. The primary LLM estimated paranoid CVSS 7 and the production ActionableScore returned 5 with recommendation Actionable Moderate / Strong Important candidate requiring manual review. The production rules then evaluated CVSS thresholds and ActionableScore thresholds. Recorded rule transitions were CVSS and initial triage stage LOW to MODERATE_KPANIC because the ActionableScore threshold rule was applied. The legacy KP specialist produced a review artifact and its decision was processed by the applicable KP rules. The legacy FD or DH downgrade specialist has no review artifact for this run. Exact triggered rule markers were INCREASED_TO_MODERATE7_FROM_LOW_BASED_ON_GUESSCVSS_AND_ACTIONABLESCOREHIGHER4. The independent weaker Aegis shadow evaluated CVSS 1.9 and ActionableScore 3 with primitive class CLASS_B and manual review REQUIRED. Its independently reconciled impact was MODERATE_KPANIC. The shadow agreed with the final production impact and aggregation did not change that impact. The final reported impact is MODERATE_KPANIC.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate / Strong Important candidate requiring manual review (with actual score 5)	MAYBE	HARDWARE  KPANIC INCREASED_TO_MODERATE7_FROM_LOW_BASED_ON_GUESSCVSS_AND_ACTIONABLESCOREHIGHER4	-	-	checked

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

ActionableScore=5
PrimitiveClass=CLASS_A
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=UNKNOWN
ImportantCandidate=YES
ManualReview=REQUIRED
AutoDowngradeAllowed=NO
RequiresHostUID0=UNKNOWN
AuthorizationDecisionBypass=NO
ProtectedResourceImpact=NONE
B4PendingReview=NO
B4PendingConfirmed=NO

1. ActionableScore

* Raw base score: 4.
* Conservative score: 5. Manual-review safety floor raises 4 -> 5 because the patch confirms an attacker-influenced stack out-of-bounds write.
* Raw paranoid score: 5.
* Paranoid score: 5.
* Final recommended bucket: **Actionable Moderate / Strong Important candidate requiring manual review**::

2. Signal breakdown

* +2 — Strong corruption primitive: `i` is derived from the Device Tree property name, then `memcpy(name, prop->name, i)` writes into a fixed 64-byte stack buffer without bounding `i`.
* +1 — Separate invalid structured-pointer use: allocated bulk entries leave `.supply` uninitialized, and `regulator_bulk_enable()` later consumes it as a string on an enable-failure path.
* +1 — Plausible kernel crash from either stack corruption or invalid `%s` dereference; no additional Availability point is awarded.
* Paranoid +1 — The invalid string is printed to kernel logs, providing a technically plausible disclosure path if it references readable memory and logs are accessible.
* No UAF, controlled reclaim, arbitrary target, LPE, or directed kernel write is shown. Confidentiality is not included in the conservative score.
* B5-R does not apply: this is a stack overwrite, not a retry-accumulated heap/slab overwrite with later corrupted-state consumption.
* B4-PENDING does not apply because no authorization decision is changed.

3. Reachability analysis

The corrupting input is an OF/Device Tree property name. The supplied evidence does not establish whether the complete trigger requires host firmware/overlay administration or is exposed through a delegated management interface. Thus neither below-host-admin access nor host-admin-only access is proven. No namespace-scoped route, ordinary-user trigger, remote path, timing race, or rare-hardware requirement is established.

4. Primitive and severity reading

The primary primitive is a concrete, attacker-influenced stack OOB write, therefore CLASS_A. The separate uninitialized `.supply` pointer is later consumed by an error-reporting kernel path and can cause an invalid read or crash. Exploit-quality control over overwritten stack state, reliable disclosure, and privilege escalation remain unproven. ImportantCandidate is YES and auto-downgrade is disallowed because dismissing the confirmed OOB write as only an error-path crash would lose a material corruption primitive.

5. One-sentence report phrase

An unbounded Device Tree supply-name copy causes a concrete stack OOB write, while an uninitialized supply pointer is separately consumed during regulator enable failure reporting.

6. Manual review advice

MANUAL CHECK REQUIRED

Review Device Tree/overlay authority and stack layout to determine practical reachability and exploit leverage.

7. Call-site confidence

Call-site confidence: high

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

Patch: regulator: of: fill in supply names in of_regulator_bulk_get_all() [ Upstream
Commit: 82ac8c4939bdbd064b4f54a580fbe4baf0d60e41
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=82ac8c4939bdbd064b4f54a580fbe4baf0d60e41

Changed files:
  drivers/regulator/of_regulator.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=82ac8c4939bdbd064b4f54a580fbe4baf0d60e41

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

The original Linux kernel CVE announcement for CVE-2026-99021 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-99021

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:L/A:H
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
  The Best / paranoid CVSS score: 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: 5

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: YES
Published priority for this report (same as in Subject): MODERATE 7.0

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).