[CVE-2026-72448][LOW] octeontx2-pf: Fix leak of SQ timestamp buffer on teardown [ Upstream

[CVE-2026-72448][LOW] octeontx2-pf: Fix leak of SQ timestamp buffer on teardown [ Upstream

[AL-KERNEL]

CVE: CVE-2026-72448
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: octeontx2-pf: Fix leak of SQ timestamp buffer on teardown [ Upstream
Commit: c642a530aaaeb9a3e356cedfe77955e7f983380e
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c642a530aaaeb9a3e356cedfe77955e7f983380e
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72448
Analysis date: Sat, 15 Aug 2026 23:28:42 -0400
ActionableScore: 1
ActionableScore lower bound: 0
Actionable bucket: Ordinary Moderate / Low-like
Manual review required: NO

Summary:
The octeontx2 PF driver leaked the SQ timestamp buffer during teardown when timestamping was used, allowing repeated privileged interface teardown cycles to cause gradual resource exhaustion but not memory corruption or privilege escalation.

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

The original Linux kernel CVE announcement for CVE-2026-72448 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72448

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-2026-72448	LOW	CHECK WITH IMPACT FROM ORIG NN IMPORTANT	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:H';*CWE-401;*CWE-772;**CWE-400;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '5.5';DESCR 'The octeontx2 pf driver can leak the SQ timestamp buffer because sq timestamps is allocated when timestamping is used but is not released during SQ resource teardown. Repeated ifdown or device removal cycles can accumulate leaked DMA backed queue memory and may eventually cause resource exhaustion. For the CVSS the PR:L is used in the paranoid score only for environments where a reduced capability admin, service account, or container root has delegated control over the affected network device. In the typical host configuration PR:H is more realistic because physical NIC teardown and device removal require administrative privileges. The issue is not network reachable and does not provide a clear memory corruption primitive. Impact is denial of service through memory exhaustion only.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 1)	YES	REMOTE INIT LEAK UAF NETWORK HARDWARE LINUS  LOWERED_FROM_HIGH_BASED_ON_GUESSCVSS  DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5 DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3	YES	NO	checked

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

ActionableScore=1
ActionableScoreLower=0

## 1. ActionableScore

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

## 2. Signal breakdown

Triggered signals:

* Availability impact realistic: +1
  The bug leaks the SQ timestamp buffer across ifdown or device removal when timestamping is used. Repeated teardown cycles could eventually contribute to resource exhaustion.

Subtracting or limiting signals:

* Requires admin/root/CAP_NET_ADMIN or equivalent in typical deployments: -2
  Triggering normally requires administrative control over the physical NIC, driver teardown, ifdown, or device removal.

* Rare or hardware-specific exposure: -1
  The affected code is specific to Marvell octeontx2 PF hardware and the timestamping path.

Not triggered:

* No remote/network-triggerable path.
* No UAF, double-free, OOB write, stale callback, arbitrary write, or object confusion.
* No confidentiality or integrity impact supported by the patch.
* No privilege escalation plausibility.
* No strong immediate DoS. The impact requires repeated resource leakage, not a single reliable crash.

## 3. Reachability analysis

The realistic trigger is local administrative control over the affected octeontx2 PF device, with timestamping enabled and repeated teardown events such as ifdown or device removal. In ordinary host deployments this maps to PR:H or equivalent administrative control. A paranoid interpretation may consider PR:L where a reduced-capability service account, container root, or delegated network administrator can repeatedly manage the affected interface, but that still does not create a memory corruption primitive.

The path is not remotely reachable through packet traffic. The affected hardware and PTP timestamping configuration are deployment-specific.

## 4. Severity interpretation

This behaves like a Low or ordinary Moderate resource leak, not an Important-class kernel vulnerability. The patch fixes a missing qmem_free() call for sq->timestamps. There is no evidence of memory corruption, privilege escalation, information disclosure, or cross-boundary policy bypass.

The paranoid score is only slightly higher because sustained repeated teardown could theoretically exhaust memory on an affected system. It should not be escalated to Actionable Moderate because the trigger is privileged and hardware/configuration-specific.

## 5. One-sentence report phrase

The octeontx2 PF driver leaked the SQ timestamp buffer during teardown when timestamping was used, allowing repeated privileged interface teardown cycles to cause gradual resource exhaustion but not memory corruption or privilege escalation.

## 6. Manual review recommendation

NO MANUAL CHECK NEEDED

This is a straightforward local privileged resource leak with no supported memory corruption, remote reachability, confidentiality impact, integrity impact, or LPE path.

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

Patch: octeontx2-pf: Fix leak of SQ timestamp buffer on teardown [ Upstream
Commit: c642a530aaaeb9a3e356cedfe77955e7f983380e
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c642a530aaaeb9a3e356cedfe77955e7f983380e

Changed files:
  drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.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=c642a530aaaeb9a3e356cedfe77955e7f983380e

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

The original Linux kernel CVE announcement for CVE-2026-72448 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72448

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:H
  The Best / paranoid CVSS score: 5.5

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: 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).