[CVE-2026-72038][LOW] net: liquidio: fix BAR resource leak on PF number failure commit c63ee62a3c4ac1a1542f4c1a4b87e2f41df5a496 upstream.

[CVE-2026-72038][LOW] net: liquidio: fix BAR resource leak on PF number failure commit c63ee62a3c4ac1a1542f4c1a4b87e2f41df5a496 upstream.

[AL-KERNEL]

CVE: CVE-2026-72038
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: net: liquidio: fix BAR resource leak on PF number failure commit c63ee62a3c4ac1a1542f4c1a4b87e2f41df5a496 upstream.
Commit: 75b924759de9427761115301308c137904aa3f99
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=75b924759de9427761115301308c137904aa3f99
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72038
Analysis date: Sun, 16 Aug 2026 08:01:08 -0400
ActionableScore: 1
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate / Low-like
Manual review required: NO

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-72038 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72038

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-2026-72038	LOW	CHECK WITH IMPACT FROM ORIG NN IMPORTANT	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';*CWE-772;CWE-404;**CWE-400;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.1';DESCR 'The liquidio PF setup path can leak mapped PCI BAR resources if cn23xx_get_pf_num fails after BAR0 and BAR1 were already mapped. Repeated failed initialization attempts could accumulate unreleased BAR mappings and may eventually cause resource exhaustion or prevent the device from being initialized correctly. For the CVSS the PR:H is used because reliable triggering normally requires administrative control over driver loading, PCI device setup, reset handling, or VM passthrough configuration. The issue is not network reachable and does not provide a clear memory corruption primitive. Impact is denial of service through resource exhaustion only, with no evidence of confidentiality or integrity impact.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 1)  SKIP CVE-2026-72038 UNKNOWN SKIP No affected files built, so skip this CVE NO  - - unknown 	MAYBE	REMOTE SIMPLEFIX LEAK ERRORPATH NETWORK  DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3	-	-	checked

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

ActionableScore=1

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

2. Signal breakdown
* Availability impact realistic: +1. Repeated failed device setup attempts could leak mapped PCI BAR resources and eventually contribute to resource exhaustion or device initialization failure.
* Requires admin/root/CAP_* in typical deployments: -2. Reliable triggering normally requires control over driver loading, PCI device setup, reset handling, SR-IOV, or VM passthrough configuration.
* Rare AND difficult-to-reach subsystem/configuration: -1. liquidio hardware and this PF setup failure path are not broad/default exposure.
* No memory corruption signal. The patch fixes missing unmap calls on an error path, not UAF, OOB access, double free, type confusion, or attacker-controlled overwrite.
* No remote/network trigger. The affected path is device initialization, not packet processing.
* Effective score is floored to 1 because the issue is a real kernel resource leak but not an actionable security primitive.

3. Reachability analysis
The bug is reachable during liquidio PF device setup after BAR0 and BAR1 are mapped and cn23xx_get_pf_num() fails. A normal unprivileged local user cannot usually trigger this path. Practical triggering requires administrative control over the driver, PCI device state, passthrough configuration, or reset/probe flows. Namespaces and containers do not normally lower this to unprivileged access unless a container is delegated unusually strong device or PCI management rights. The path is hardware and driver specific and is not default reachable on most systems.

4. Severity interpretation
This behaves like a low severity resource leak or ordinary Moderate issue, not an Important-class vulnerability. The realistic impact is local privileged denial of service or failed device recovery after repeated error-path execution. There is no supported privilege escalation path and no demonstrated confidentiality or integrity impact. Theoretical risk does not go beyond resource exhaustion because the leaked object is a mapped PCI BAR resource and the patch does not show stale reuse, write-after-free, object confusion, or arbitrary memory corruption.

5. One-sentence report phrase
The liquidio PF setup error path can leak mapped PCI BAR resources when PF number detection fails, requiring administrative device-management control to trigger and mainly causing potential resource exhaustion or device initialization failure.

6. Manual review recommendation
NO MANUAL CHECK NEEDED. This can be auto-closed for security triage because it is a privileged, hardware-specific resource leak without memory corruption, network reachability, privilege escalation, or sensitive data exposure evidence.

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

Patch: net: liquidio: fix BAR resource leak on PF number failure commit c63ee62a3c4ac1a1542f4c1a4b87e2f41df5a496 upstream.
Commit: 75b924759de9427761115301308c137904aa3f99
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=75b924759de9427761115301308c137904aa3f99

Commit description:

If cn23xx_get_pf_num() fails, the function returns without
unmapping either BAR. Unmap both BARs before returning from
the error path.

Found by manual code review.

Fixes: 0c45d7fe12c7 ("liquidio: fix use of pf in pass-through mode in a virtual machine")
Cc: stable@vger.kernel.org
Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com>
Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>
Link: https://patch.msgid.link/20260624064013.2809570-1-haoxiang_li2024@163.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat -rw-r--r-- drivers/net/ethernet/cavium/liquidio/cn23xx_pf_device.c 18

Changed files:
  drivers/net/ethernet/cavium/liquidio/cn23xx_pf_device.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=75b924759de9427761115301308c137904aa3f99

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

The original Linux kernel CVE announcement for CVE-2026-72038 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72038

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:L
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS score: 4.1

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: 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).