[CVE-2026-99259][LOW] soc/tegra: pmc: Fix uninitialised clock rate [ Upstream

[CVE-2026-99259][LOW] soc/tegra: pmc: Fix uninitialised clock rate [ Upstream

[AL-KERNEL]

CVE: CVE-2026-99259
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: soc/tegra: pmc: Fix uninitialised clock rate [ Upstream
Commit: 43bc7d5707bbbf75e56db849b987193d6e866ec6
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=43bc7d5707bbbf75e56db849b987193d6e866ec6
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-99259
Analysis date: Tue, 03 Nov 2026 22:12:25 -0400
ActionableScore: 0
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate
Manual review required: NO

Summary:
A missing clock-rate assignment on legacy 32-bit Tegra systems causes a suspend-path warning without evidence of memory corruption, authorization bypass, or security-relevant impact.

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

The original Linux kernel CVE announcement for CVE-2026-99259 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-99259

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-2026-99259	LOW	https://www.kernelcve.org/list/?q=CVE-2026-99259 CHECK WITH IMPACT FROM ORIG NN LOW | 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:L/PR:L/UI:N/S:U/C:N/I:N/A:L';CWE-665;*CWE-457;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:N';BEST CVSS score: '3.3';DESCR 'A missing assignment leaves the early PMC clock rate at zero on legacy 32-bit Tegra systems after the driver creates the main PMC context dynamically. The confirmed symptom is a warning in tegra_pmc_enter_suspend_mode during system suspend. There is no evidence of an invalid pointer dereference, out of bounds access, use after free, information leak, or write primitive. For the CVSS the PR:L value in the paranoid vector covers deployments where a local user session can request suspend through a power management service. The worst grounded impact is a possible low availability effect if suspend setup fails, while confidentiality and integrity remain unaffected. Automated impact decision path. The original SimpleNet classifier selected LOW. The primary LLM estimated paranoid CVSS 3.3 and the production ActionableScore returned 0 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 0 with primitive class NONE 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 0)	MAYBE	WARNONLY SIMPLEFIX LEAK HARDWARE LINUS 	-	-	checked

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

ActionableScore=0
PrimitiveClass=NONE
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: 0.
* Conservative score: 0; no floor or cap applied.
* Raw paranoid score: 0.
* Paranoid score: 0; WARN_ON alone contributes no availability point.
* Final recommended bucket: **Ordinary Moderate**::

2. Signal breakdown

* +0 uninitialized-value correction: `early_pmc->rate` remains zero because the dynamically initialized rate was not copied into the early PMC context.
* +0 warning: the confirmed result is a warning during suspend, not a demonstrated panic, host-wide denial of service, or persistent failure.
* No UAF, OOB access, overwrite, disclosure, authorization bypass, or protected-state corruption is shown.
* B5-R does not apply: there is no heap OOB write, retry-accumulated index, attacker-influenced retry sequence, or later consumption of corrupted structured state.
* B3-PENDING does not apply: no shared-backing write exists.
* No availability point is awarded from the merely possible failure of suspend setup.

3. Reachability analysis

The affected path is limited to legacy 32-bit Tegra suspend handling. A local session may be able to request suspend through a power-management service, but the supplied evidence does not establish the complete privilege model; therefore `HostAdminRequired` and `RequiresHostUID0` remain unknown. No namespace capability or namespace-scoped trigger is involved. Special legacy Tegra hardware is required, but no penalty is needed because the raw score is already zero. No race or attacker-controlled data is present.

4. Primitive and severity reading

The defect is a missing initialization/copy of a clock-rate scalar. The zero value reaches suspend-mode calculations and causes a warning. It is neither active-state corruption nor a lifetime violation. No security-relevant effect beyond diagnostic or possible device power-management malfunction is established. Consequently the primitive class is NONE, there is no Important candidate, and automatic downgrade is safe.

5. One-sentence report phrase

A missing clock-rate assignment on legacy 32-bit Tegra systems causes a suspend-path warning without evidence of memory corruption, authorization bypass, or security-relevant impact.

6. Manual review advice

NO MANUAL CHECK NEEDED

The one-line initialization fix and documented warning provide no unresolved security primitive.

7. Call-site confidence

Call-site confidence: high

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

Patch: soc/tegra: pmc: Fix uninitialised clock rate [ Upstream
Commit: 43bc7d5707bbbf75e56db849b987193d6e866ec6
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=43bc7d5707bbbf75e56db849b987193d6e866ec6

Changed files:
  drivers/soc/tegra/pmc.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=43bc7d5707bbbf75e56db849b987193d6e866ec6

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

The original Linux kernel CVE announcement for CVE-2026-99259 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-99259

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:N
  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).