[CVE-2026-80940][LOW] wifi: rtw88: pci: fix resource leak on failed NAPI setup

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

CVE: CVE-2026-80940
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: wifi: rtw88: pci: fix resource leak on failed NAPI setup
Commit: 481fff9bda01720c70b19fb260808145a3f21594
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=481fff9bda01720c70b19fb260808145a3f21594
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80940
Analysis date: Fri, 11 Sep 2026 20:05:41 -0400
ActionableScore: 0
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate
Manual review required: NO

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-80940 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80940

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-2026-80940	LOW	https://www.kernelcve.org/list/?q=CVE-2026-80940 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:H/UI:N/S:U/C:N/I:N/A:H';*CWE-772;*CWE-401;CWE-404;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.1';DESCR 'A resource leak in the rtw88 PCI probe error path can occur when PCI resources are allocated before NAPI setup and rtw_pci_napi_init then fails. The failed path skipped rtw_pci_destroy, so resources allocated by rtw_pci_setup_resource could remain allocated after an unsuccessful driver probe. For the CVSS the PR:H is used because reliable triggering normally requires administrative control over driver probe, module bind or device management. The issue is not network reachable and is not triggered by WiFi packet traffic. Impact is denial of service only through possible resource exhaustion after repeated failed probe attempts, with no evidence of memory corruption, information disclosure or privilege escalation.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 0)	YES	REMOTE INIT SIMPLEFIX LEAK ERRORPATH NETWORK HARDWARE LINUS TEST  DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3	YES	NO	checked

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

ActionableScore=0
PrimitiveClass=NONE
RealUAF=NO
HostAdminRequired=YES
NamespaceScopedPrivilege=NO
ImportantCandidate=NO
ManualReview=NO
AutoDowngradeAllowed=YES

1. ActionableScore

* Raw conservative score: -1
* Conservative score: 0
* Applied conservative floor/cap: lower bound -1 -> 0
* Raw paranoid score: 0
* Paranoid score: 0
* Final recommended bucket: **Ordinary Moderate**::

2. Signal breakdown

Positive signals:

* +1 Concrete persistent kernel resource/reference leak. rtw_pci_setup_resource allocates PCI resources and the failed rtw_pci_napi_init path skipped rtw_pci_destroy, leaving those resources allocated.
* +1 Paranoid resource exhaustion concern. Repeated failed probe attempts could accumulate leaked resources, but this requires privileged and abnormal repeated driver probe failure.

Negative signals:

* -2 Full host-admin-equivalent requirement. Reliable triggering requires control over PCI driver probing, module bind or unbind, device management, or comparable host-level fault-injection conditions.

Non-awarded signals:

* No RealUAF. The patch fixes a missing cleanup call, not post-free object use.
* No repeated release/refcount signal. There is no first release followed by a second lifetime mutation on the same dangling reference.
* No controlled reclaim or arbitrary write demonstrated.
* No confidentiality or integrity signal.
* No reliable kernel crash signal from a single operation.
* No remote reachability. WiFi packet traffic does not reach this probe error path.
* No race/timing penalty. This is an ordered error-path cleanup bug, not a race.

3. Reachability analysis

The relevant path is PCI driver probe for rtw88. The leak occurs only if rtw_pci_napi_init fails after PCI resources have already been allocated. A normal remote attacker sending WiFi traffic cannot trigger this path.

Reliable attacker-controlled triggering normally requires host administrative control over driver loading, binding, unbinding, reprobe, PCI device management, or kernel fault-injection style setup. The complete trigger is not namespace-scoped. A network namespace or container capability is not sufficient to manage the physical PCI probe path. The system also needs affected rtw88 PCI hardware or an equivalent test environment, but no separate rare-hardware penalty is needed because the host-admin requirement already dominates practical reachability.

4. Primitive and severity interpretation

The exact primitive is a persistent resource leak in an error path. It is not memory corruption, not UAF, not double free, and not an authorization bypass. The affected stale state is allocated PCI driver resource state that should have been destroyed by rtw_pci_destroy on probe failure.

The demonstrated consequence is resource leakage after failed initialization. The speculative consequence is resource exhaustion after repeated privileged failed probes. There is no meaningful exploitation leverage beyond availability pressure, and no evidence of privilege escalation, information disclosure, controlled kernel corruption, or security-boundary bypass.

PrimitiveClass is NONE because no meaningful corruption, ownership, lifetime-after-free, authorization, or semantic security primitive is established. ImportantCandidate is NO because this is a constrained host-admin-gated resource leak. AutoDowngradeAllowed is YES because automatic downgrade would not lose an unresolved kernel corruption or boundary-bypass primitive.

5. One-sentence report phrase

A resource leak in the rtw88 PCI probe error path can leave PCI resources allocated when NAPI setup fails, but practical triggering requires host-level driver or device management and the impact is limited to possible resource-exhaustion DoS.

6. Manual review recommendation

NO MANUAL CHECK NEEDED

Reason: this is a host-admin-gated resource leak with no UAF, no memory corruption, no network trigger, no authorization bypass, and no plausible Important-class primitive.

7. Call-site confidence

Call-site confidence: high

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

Patch: wifi: rtw88: pci: fix resource leak on failed NAPI setup
Commit: 481fff9bda01720c70b19fb260808145a3f21594
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=481fff9bda01720c70b19fb260808145a3f21594

Commit description:

rtw_pci_probe() allocates PCI resources through
rtw_pci_setup_resource() before it sets up NAPI. If
rtw_pci_napi_init() fails, the error path jumps straight to
err_pci_declaim and skips rtw_pci_destroy(), leaving the PCI
resources allocated by rtw_pci_setup_resource() behind.

Add a dedicated cleanup label for the NAPI setup failure path so probe
destroys the PCI resources.

The bug was first flagged by an experimental analysis tool we are
developing for kernel memory-management bugs while analyzing current
mainline kernels. The tool is still under development and is not yet
publicly available. Manual inspection confirms that the bug is still
present in v7.1-rc7.

An x86_64 allyesconfig build showed no new warnings. As we do not have a
suitable rtw88 PCI board to test with, no runtime testing was able to be
performed.

Fixes: d0bcb10 ("wifi: rtw88: Un-embed dummy device")
Cc: stable@vger.kernel.org
Signed-off-by: Dawei Feng <dawei.feng@seu.edu.cn>
Acked-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20260617013502.114057-1-dawei.feng@seu.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  drivers/net/wireless/realtek/rtw88/pci.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=481fff9bda01720c70b19fb260808145a3f21594

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

The original Linux kernel CVE announcement for CVE-2026-80940 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80940

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: 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).