[CVE-2026-64224][MODERATE 7.0] octeontx2-pf: fix double free in rvu_rep_rsrc_init()

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

CVE: CVE-2026-64224
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: octeontx2-pf: fix double free in rvu_rep_rsrc_init()
Commit: 8864b664d0443ecb8e56690e5546fcda5fe5e81b
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8864b664d0443ecb8e56690e5546fcda5fe5e81b
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64224
Analysis date: Fri, 24 Jul 2026 12:10:07 -0400
ActionableScore: 5
ActionableScore lower bound: 3
Actionable bucket: Actionable Moderate at minimum
Manual review required: YES

Summary:
A double free in the OcteonTX2 representor initialization error path can occur when hardware resource setup fails and already unwound SQ, CQ, and aura resources are freed again, causing at least a local kernel crash risk and requiring manual review due to kernel memory corruption potential.

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ABOUT THIS REPORT
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The original Linux kernel CVE announcement for CVE-2026-64224 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64224

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.

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AL-KERNEL CLASSIFICATION RESULT
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CVE-2026-64224	MODERATE	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:H/I:H/A:H';CWE-415;*CWE-416;*CWE-664;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:H';BEST CVSS score: '7';DESCR 'A double free can occur in the OcteonTX2 representor initialization error path. rvu_rep_rsrc_init allocates queue memory and then calls otx2_init_hw_resources, but if hardware resource setup fails, that helper already unwinds partially initialized SQ, CQ, and aura state before returning an error. The old representor error path could then call otx2_free_hw_resources again and free the same resources a second time, creating a kernel memory corruption candidate and likely crash. For the CVSS the PR:L is used in the paranoid score because a less privileged local service account or delegated device management context may be able to trigger driver recovery or initialization paths in some deployments, although typical systems require administrator privileges. The issue is not network reachable and depends on OcteonTX2 representor hardware plus a failure during hardware resource setup. Impact is at least local denial of service via kernel crash and in the worst case may allow confidentiality or integrity impact due to kernel double free memory corruption.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate at minimum (with actual score 4)	YES	REMOTE INIT ERRORPATH NETWORK HARDWARE LINUS  DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5	YES	NO	checked

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ACTIONABLESCORE ANALYSIS
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ActionableScore=5
ActionableScoreLower=3

## 1. ActionableScore

* Conservative score: 3
* Paranoid score: 5
* Final recommended bucket: **Actionable Moderate at minimum**

## 2. Signal breakdown

Conservative signals:

* Memory corruption, Strong corruption primitive: +2. The patch prevents a confirmed double free of SQ, CQ, and aura related hardware resources.
* Real lifetime corruption: +1. The bug is an error-path lifetime mismatch where resources already unwound by `otx2_init_hw_resources()` are freed again.
* Reliable kernel crash / strong DoS: +1. A double free in kernel driver cleanup is a realistic crash candidate if the failing path is reached.
* Privileged kernel/device-management memory corruption path: +1. The bug is in NIC representor hardware resource initialization and cleanup.
* Firmware-mediated external influence: +1. Triggering depends on hardware or firmware resource setup failure rather than ordinary local input.
* Requires admin/root/CAP_* in typical deployments: -2. Loading, probing, configuring, or forcing representor initialization paths is normally administrative.
* Rare and difficult-to-reach subsystem/configuration: -1. The path requires OcteonTX2 representor hardware and a failure during hardware resource setup.

Paranoid additions/adjustments:

* Weak LPE concern: +1. Double free is a kernel memory corruption class that may theoretically become more than DoS, although no reclaim, overwrite, or controlled reuse primitive is shown.
* Reduced privilege interpretation: +1 relative to conservative. In some deployments, recovery or device management may be reachable from a service account, container root, or delegated management context rather than full host root.

## 3. Reachability analysis

The bug is local and device-specific. It requires OcteonTX2 representor hardware and an error from `otx2_init_hw_resources()` during representor resource initialization. It is not network reachable in the ordinary packet-processing sense.

Typical triggering requires administrative control over driver probing, device setup, reset, or representor configuration. Namespace or container impact is limited unless device management is delegated into a container or a reduced-capability service can initiate the relevant recovery path. Runtime validation was not performed, which lowers confidence in practical exploitability but not in the underlying double-free bug class.

Call-site confidence: high. The patch shows the failing call, the incorrect cleanup label, and the corrected unwind path.

## 4. Severity interpretation

This is not an ordinary low-risk cleanup bug because the patch fixes a concrete double free in kernel driver resource lifetime handling. Realistic exploitation is constrained by rare hardware, privileged setup paths, and a specific initialization failure, so the conservative score stays in borderline manual-review territory.

The theoretical risk is higher because double free is a memory corruption class and can sometimes become privilege escalation if object reuse is controllable. In this patch, no attacker-controlled reclaim, object replacement, arbitrary write, or callback control is demonstrated, so it should be treated as Actionable Moderate rather than a strong Important candidate.

## 5. One-sentence report phrase

A double free in the OcteonTX2 representor initialization error path can occur when hardware resource setup fails and already unwound SQ, CQ, and aura resources are freed again, causing at least a local kernel crash risk and requiring manual review due to kernel memory corruption potential.

## 6. Manual review recommendation

MANUAL CHECK REQUIRED

Reason: confirmed kernel double free in a privileged device-management path, with constrained but non-zero memory-corruption and LPE concern.

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

Patch: octeontx2-pf: fix double free in rvu_rep_rsrc_init()
Commit: 8864b664d0443ecb8e56690e5546fcda5fe5e81b
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8864b664d0443ecb8e56690e5546fcda5fe5e81b

Commit description:

rvu_rep_rsrc_init() allocates queue memory before calling
otx2_init_hw_resources(). When hardware resource setup fails,
otx2_init_hw_resources() already unwinds the partially initialized
SQ, CQ, and aura state before returning an error. The representor
error path then calls otx2_free_hw_resources() again and can free
the same resources a second time.

Fix this by splitting the cleanup labels so that a failure from
otx2_init_hw_resources() only releases queue memory. Keep the
otx2_free_hw_resources() call for failures that happen after
hardware resource initialization completed successfully.

The bug was first flagged by an experimental analysis tool we are
developing for kernel memory-management bugs while analyzing
v6.13-rc1. The tool is still under development and is not yet publicly
available. Manual inspection confirms that the bug is still
present in v7.1-rc3.

Runtime validation was not performed because reproducing this path
requires OcteonTX2 representor hardware.

Fixes: 3937b73 ("octeontx2-pf: Create representor netdev")
Cc: stable@vger.kernel.org # v6.13+
Signed-off-by: Zilin Guan <zilin@seu.edu.cn>
Signed-off-by: Dawei Feng <dawei.feng@seu.edu.cn>
Reviewed-by: Geetha sowjanya <gakula@marvell.com>
Link: https://patch.msgid.link/20260513151320.213260-1-dawei.feng@seu.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  drivers/net/ethernet/marvell/octeontx2/nic/rep.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=8864b664d0443ecb8e56690e5546fcda5fe5e81b

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

The original Linux kernel CVE announcement for CVE-2026-64224 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64224

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: 3
  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: NO
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).