[CVE-2026-46152][IMPORTANT] wifi: mac80211: drop stray 'static' from fast-RX rx_result

[CVE-2026-46152][IMPORTANT] wifi: mac80211: drop stray 'static' from fast-RX rx_result

[AL-KERNEL]

CVE: CVE-2026-46152
Priority: IMPORTANT
AL-KERNEL base severity: IMPORTANT
KPANIC flag: YES
Patch: wifi: mac80211: drop stray 'static' from fast-RX rx_result
Commit: 03584528bfffb195e384698af9148b94e42e3f14
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=03584528bfffb195e384698af9148b94e42e3f14
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46152
Analysis date: Thu, 28 May 2026 12:11:12 -0400
ActionableScore: 8
ActionableScore lower bound: 5
Actionable bucket: Strong Important candidate / Actionable Moderate at minimum
Manual review required: YES

Summary:
mac80211 fast RX used a shared static `rx_result`, allowing concurrent RX callers to corrupt each other decisions and potentially double-process an already consumed skb in Wi-Fi mesh fast-RX.

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ABOUT THIS REPORT
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The original Linux kernel CVE announcement for CVE-2026-46152 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46152

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: IMPORTANT
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-2026-46152	IMPORTANT	CHECK	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H';CWE-362;*CWE-416;CWE-667;*CWE-664;Other CVSS 'AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H';BEST CVSS score: '7.5';DESCR 'mac80211 fast RX used a static rx_result variable inside ieee80211_invoke_fast_rx, so concurrent RX callers could overwrite each other result. This can make a packet already queued or consumed by ieee80211_rx_mesh_data continue into ieee80211_rx_8023, or make a packet that should continue return as queued. For the CVSS the PR:N is used because an RF adjacent peer may trigger parallel RX traffic without local privileges on the victim once mesh fast RX is active. The issue is not Internet reachable and requires a specific Wi-Fi mesh fast RX race condition. Impact is at least denial of service through kernel crash or packet processing corruption, and worst case may allow confidentiality or integrity impact because double processing of consumed skb data can become a kernel lifetime corruption issue.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Strong Important candidate / Actionable Moderate at minimum (with actual score 7) 	MAYBE	REMOTE SIMPLEFIX KPANIC PACKET  KPANIC INCREASED_TO_HIGH_BASED_ON_GUESSCVSS	-	-	checked

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ACTIONABLESCORE ANALYSIS
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ActionableScore=8
ActionableScoreLower=5

## 1. ActionableScore

* Conservative score: 5
* Paranoid score: 8
* Final recommended bucket: **Strong Important candidate / Actionable Moderate at minimum**::

## 2. Signal breakdown

Conservative signals:

* Firmware/RF-mediated external influence: +1. An RF-adjacent peer can contribute traffic that reaches the Wi-Fi mesh fast-RX path.
* Reliable kernel crash / strong DoS: +1. Incorrect RX result sharing can cause packets to be misprocessed and may crash or destabilize mac80211.
* Common networking packet-processing path: +1. mac80211 RX processing is a core Wi-Fi packet path.
* Availability impact realistic: +1. Packet processing corruption can break connectivity or cause kernel failure.
* Integrity impact plausible: +1. The wrong per-packet decision can cause incorrect packet handling, including processing a packet that was already consumed.
* Hard/racy condition: -1. The issue requires concurrent RX callers and a race window.

Paranoid additional signals:

* Generic memory corruption: +2. Continuing with an skb after it was queued or consumed can plausibly become use-after-free or lifetime corruption.
* Real lifetime corruption: +1. The affected object is per-packet processing state, and stale/shared results can cause double processing of consumed skb state.
* Weak to strong LPE concern: +1. skb lifetime corruption in a kernel networking path can sometimes be exploitable, though no concrete primitive is shown.

## 3. Reachability analysis

The issue is RF-adjacent, not Internet-reachable. An attacker in radio range may generate traffic that increases parallel RX activity once the victim is using Wi-Fi mesh fast-RX.

Practical exploitation requires mesh fast-RX support, concurrent packet processing, and a timing window where the shared static `rx_result` is overwritten between `ieee80211_rx_mesh_data()` and the switch on the result. Local privileges are not required for the RF-adjacent trigger, but configuration of mesh mode is an environmental precondition.

## 4. Severity interpretation

This is at least actionable Moderate and a Strong Important candidate under paranoid triage. The realistic impact is packet-processing corruption or DoS. The higher concern is possible skb lifetime corruption if an already queued or consumed packet is processed again.

The patch does not show a demonstrated arbitrary write or LPE chain, so the Important classification is a manual-review candidate rather than proven exploitation.

## 5. One-sentence report phrase

mac80211 fast RX used a shared static `rx_result`, allowing concurrent RX callers to corrupt each other decisions and potentially double-process an already consumed skb in Wi-Fi mesh fast-RX.

## 6. Manual review recommendation

MANUAL CHECK REQUIRED

This is an RF-adjacent race in a packet-processing path with plausible skb lifetime corruption. Practical severity depends on mesh fast-RX exposure and race reliability.

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

Patch: wifi: mac80211: drop stray 'static' from fast-RX rx_result
Commit: 03584528bfffb195e384698af9148b94e42e3f14
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=03584528bfffb195e384698af9148b94e42e3f14

Commit description:

ieee80211_invoke_fast_rx() is documented as safe for parallel RX, but
its per-invocation rx_result is declared static. Concurrent callers then
share one instance and can overwrite each other's result between
ieee80211_rx_mesh_data() and the switch on res.

That can make a packet that was queued or consumed by
ieee80211_rx_mesh_data() fall through into ieee80211_rx_8023(), or make
a packet that should continue return as queued.

Make res an automatic variable so each invocation keeps its own result.

Fixes: 3468e1e ("wifi: mac80211: add mesh fast-rx support")
Cc: stable@vger.kernel.org
Signed-off-by: Catherine <enderaoelyther@gmail.com>
Link: https://patch.msgid.link/20260424131435.83212-2-enderaoelyther@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  net/mac80211/rx.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=03584528bfffb195e384698af9148b94e42e3f14

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

The original Linux kernel CVE announcement for CVE-2026-46152 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46152

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:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
  The Best / paranoid CVSS vector: AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
  The Best / paranoid CVSS score: 7.5

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: 5
  Paranoid ActionableScore: 8

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: IMPORTANT
KPANIC detected for this report: YES
Published priority for this report (same as in Subject): IMPORTANT

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).