[CVE-2026-46125][IMPORTANT] wifi: mac80211: remove station if connection prep fails

[CVE-2026-46125][IMPORTANT] wifi: mac80211: remove station if connection prep fails

[AL-KERNEL]

CVE: CVE-2026-46125
Priority: IMPORTANT
AL-KERNEL base severity: IMPORTANT
KPANIC flag: YES
Patch: wifi: mac80211: remove station if connection prep fails
Commit: fe75fa1ac9a92990f7fc3d34b17808fd933071b2
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fe75fa1ac9a92990f7fc3d34b17808fd933071b2
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46125
Analysis date: Thu, 28 May 2026 13:55:16 -0400
ActionableScore: 7
ActionableScore lower bound: 6
Actionable bucket: Strong Important candidate / Actionable Moderate at minimum
Manual review required: YES

Summary:
A mac80211 MLO connection preparation failure can leave a stale station associated with a removed vif link, causing debugfs use-after-free or double-free and a potential kernel crash when debugfs is enabled.

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ABOUT THIS REPORT
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The original Linux kernel CVE announcement for CVE-2026-46125 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46125

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-2026-46125	IMPORTANT	CHECK	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H';*CWE-416;CWE-415;CWE-459;Other CVSS 'AV:A/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H';BEST CVSS score: '7.1';DESCR 'mac80211 MLO connection preparation failure can leave an existing station attached to a link while the vif is reset from MLD to non MLD. When debugfs is enabled, the MLD transition recreates debugfs state and the stale station link relationship can trigger use-after-free or double-free. For the CVSS the PR:N is used in the paranoid adjacent attacker model because a nearby malicious AP may influence MLO association failure once the client attempts to connect, without needing a local account on the victim. UI:R and AC:H are kept because the victim must attempt WiFi association and the failure path depends on specific MLO state and debugfs exposure. Impact is at least denial of service via kernel crash and in the paranoid case may include confidentiality and integrity impact due to memory corruption.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Strong Important candidate / Actionable Moderate at minimum (with actual score 7) 	MAYBE	REMOTE LOCK DANGER UAF DEBUGFS KPANIC  KPANIC INCREASED_TO_HIGH_BASED_ON_ACTIONABLESCOREHIGHEREQTHAN7	-	-	checked

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ACTIONABLESCORE ANALYSIS
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ActionableScore=7
ActionableScoreLower=6

## 1. ActionableScore

* Conservative score: **6**
* Paranoid score: **7**
* Final recommended bucket: **Strong Important candidate / Actionable Moderate at minimum**::

## 2. Signal breakdown

* Remote or adjacent network influence: **+2**. A nearby AP can plausibly influence MLO association behavior and connection preparation failure, although user association is needed.
* Strong memory corruption primitive: **+2**. The commit explicitly says the bug fixes a use-after-free/double-free in debugfs.
* Real lifetime corruption: **+1**. A stale station remains tied to a vif link that is removed or recreated during MLD to non-MLD reset.
* Weak LPE concern: **+1**. UAF/double-free is a serious class, but no controlled reclaim, overwrite, or privilege escalation primitive is demonstrated.
* Reliable kernel crash / strong DoS: **+1**. The realistic impact is kernel crash through debugfs object lifetime corruption.
* Availability impact realistic: **+1**. A crash or lockup is plausible once the bad state is reached.
* Special conditions: **-1**. Requires MLO connection preparation failure and debugfs enabled, so exploitation is not generic WiFi packet parsing.

## 3. Reachability analysis

The bug is reached during mac80211 MLO connection preparation failure. A local user is not necessarily required if a victim device attempts to connect to a nearby malicious or misbehaving MLO AP, but user interaction is likely because the client must initiate or accept association. Containers and namespaces are not central. The issue is not Internet-routable, but it is adjacent wireless reachable in the paranoid model. Practical exploitation depends on MLO support, the failure path, and debugfs being enabled.

## 4. Severity interpretation

This is stronger than ordinary Moderate because the patch explicitly mentions UAF/double-free. The realistic demonstrated impact is DoS through kernel memory lifetime corruption in debugfs. Privilege escalation is not proven, and the conditions are constrained, but UAF/double-free in a common wireless subsystem should not be auto-closed without review.

## 5. One-sentence report phrase

A mac80211 MLO connection preparation failure can leave a stale station associated with a removed vif link, causing debugfs use-after-free or double-free and a potential kernel crash when debugfs is enabled.

## 6. Manual review recommendation

**MANUAL CHECK REQUIRED**

Manual review is required because this is explicit UAF/double-free in mac80211, even though it is gated by MLO failure handling and debugfs exposure.

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

Patch: wifi: mac80211: remove station if connection prep fails
Commit: fe75fa1ac9a92990f7fc3d34b17808fd933071b2
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fe75fa1ac9a92990f7fc3d34b17808fd933071b2

Commit description:

If connection preparation fails for MLO connections, then the
interface is completely reset to non-MLD. In this case, we must
not keep the station since it's related to the link of the vif
being removed. Delete an existing station. Any "new_sta" is
already being removed, so that doesn't need changes.

This fixes a use-after-free/double-free in debugfs if that's
enabled, because a vif going from MLD (and to MLD, but that's
not relevant here) recreates its entire debugfs.

Cc: stable@vger.kernel.org
Fixes: 81151ce ("wifi: mac80211: support MLO authentication/association with one link")
Reviewed-by: Miriam Rachel Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20260505151533.c4e52deb06ad.Iafe56cec7de8512626169496b134bce3a6c17010@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  net/mac80211/mlme.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=fe75fa1ac9a92990f7fc3d34b17808fd933071b2

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

The original Linux kernel CVE announcement for CVE-2026-46125 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46125

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:R/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS vector: AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
  The Best / paranoid CVSS score: 7.1

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: 6
  Paranoid ActionableScore: 7

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).