[CVE-2026-72005][LOW] wifi: rt2x00: avoid full teardown before work setup in probe

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

CVE: CVE-2026-72005
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: wifi: rt2x00: avoid full teardown before work setup in probe
Commit: 8b58d1f1356df6a7d2de3f55bb665b18b04ffda0
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8b58d1f1356df6a7d2de3f55bb665b18b04ffda0
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72005
Analysis date: Sat, 15 Aug 2026 15:33:25 -0400
ActionableScore: 2
ActionableScore lower bound: 0
Actionable bucket: Ordinary Moderate / Low-like
Manual review required: NO

Summary:
Early rt2x00 probe failures could enter a full teardown path before work items were initialized, causing invalid work drains and possible local DoS under forced allocation failure conditions.

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

The original Linux kernel CVE announcement for CVE-2026-72005 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72005

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-2026-72005	LOW	CHECK WITH IMPACT FROM ORIG NN MODERATE	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';CWE-665;CWE-754;CWE-703;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.7';DESCR 'rt2x00 probe error handling can call the full remove path before intf_work autowakeup_work and sleep_work are initialized. This can make rt2x00lib_remove_dev drain invalid work items after an early allocation failure during driver probe. For the CVSS the PR:L is used only for the paranoid score, because a local user might indirectly influence probe timing or memory pressure in some deployments, while reliable triggering usually requires stronger control over driver probing or fault injection. The issue is not network reachable and does not provide a clear UAF, OOB write, or information leak primitive. Impact is denial of service at most through warnings, invalid work drains, or a crash on debug or panic_on_warn configurations.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 1)	YES	REMOTE INIT NETWORK  DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3	NO	NO	checked

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

ActionableScore=2
ActionableScoreLower=0

## 1. ActionableScore

* Conservative score: 0
* Paranoid score: 2
* Final recommended bucket: **Ordinary Moderate / Low-like**::

## 2. Signal breakdown

Conservative signals:

* Weak/indirect corruption candidate: +1. The remove path may drain work items before they are initialized, but the patch does not show UAF, OOB write, type confusion, callback control, or attacker-controlled object reuse.
* Requires admin/root/CAP_* in typical deployments: -2. Reliable triggering normally requires driver probe control, device setup, module binding, fault injection, or forced allocation failure.
* Hard or unreliable race / special condition required: -1. The described reproducer forces `alloc_ordered_workqueue()` failure in QEMU, which is not an ordinary user-triggerable path.
* Rare AND difficult-to-reach subsystem/configuration: -1. The issue is specific to rt2x00 WiFi probe failure handling and requires the affected hardware or emulated device path.
* Availability impact realistic: +1. The likely impact is invalid work drains, DEBUG_OBJECTS warnings, or crash in debug / panic_on_warn style configurations.

Paranoid signals:

* Local unprivileged trigger: +1. A local user may indirectly contribute through memory pressure or device reprobe timing in some deployments, but this is not reliable.
* Weak/indirect corruption candidate: +1. The bug involves invalid operations on not-yet-initialized work structures, but without a demonstrated memory corruption primitive.
* Availability impact realistic: +1. A crash is possible in stricter debug or panic_on_warn configurations.
* Hard or unreliable special condition required: -1. The failure needs early allocation failure before work initialization.

No score is added for LPE, strong memory corruption, real UAF, remote reachability, or high-control unprivileged data-plane API.

Call-site confidence: medium. The patch shows the affected probe error paths and the commit describes the teardown consequence, but the full `rt2x00lib_remove_dev()` internals are not included.

## 3. Reachability analysis

The bug is reached during rt2x00 device probing when early allocation fails before `intf_work`, `autowakeup_work`, and `sleep_work` are initialized. In typical deployments, a normal remote attacker cannot trigger this path. Reliable triggering requires local control over driver/device probing, fault injection, forced allocation failure, or unusual memory pressure at a precise initialization point.

Namespaces and containers do not materially lower the conservative privilege requirement unless the environment delegates device management or module binding to a reduced-privilege actor. The affected path is not a packet-processing path and is not network reachable.

## 4. Severity interpretation

This behaves like a Low-like or ordinary Moderate robustness bug, not an Important-class vulnerability. The theoretical concern is invalid teardown of uninitialized work items, but the patch does not support UAF reclaim, overwrite, stale callback dispatch, type confusion, or privilege escalation. Realistic impact is denial of service at most, mainly in debug or panic_on_warn configurations.

## 5. One-sentence report phrase

Early rt2x00 probe failures could enter a full teardown path before work items were initialized, causing invalid work drains and possible local DoS under forced allocation failure conditions.

## 6. Manual review recommendation

NO MANUAL CHECK NEEDED

The issue has low practical exploitability, no remote path, no demonstrated memory corruption primitive, and no plausible privilege escalation evidence from the patch context.

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

Patch: wifi: rt2x00: avoid full teardown before work setup in probe
Commit: 8b58d1f1356df6a7d2de3f55bb665b18b04ffda0
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8b58d1f1356df6a7d2de3f55bb665b18b04ffda0

Commit description:

rt2x00lib_probe_dev() uses the full rt2x00lib_remove_dev() teardown for
all probe failures. However, drv_data allocation and workqueue allocation
can fail before intf_work, autowakeup_work and sleep_work have been
initialized.

Do not enter the full remove path until the probe has reached the point
where those work items are set up. Return directly for drv_data allocation
failure, and use a small early cleanup path for workqueue allocation
failure.

This issue was found by our static analysis tool and then confirmed by
manual review of rt2x00lib_probe_dev() and rt2x00lib_remove_dev(). The
early probe exits should not call a common teardown path that assumes the
later work setup has already completed.

A QEMU PoC forced alloc_ordered_workqueue() to fail before the work
initializers are reached. The resulting fail path entered
rt2x00lib_remove_dev(), and DEBUG_OBJECTS reported invalid work drains with
rt2x00lib_probe_dev() and rt2x00lib_remove_dev() in the stack.

Fixes: 1ebbc48 ("rt2x00: Introduce concept of driver data in struct rt2x00_dev.")
Fixes: 0439f53 ("rt2x00: Move TX/RX work into dedicated workqueue")
Cc: stable@vger.kernel.org
Signed-off-by: Runyu Xiao <runyu.xiao@seu.edu.cn>
Link: https://patch.msgid.link/20260619073104.1809161-1-runyu.xiao@seu.edu.cn
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  drivers/net/wireless/ralink/rt2x00/rt2x00dev.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=8b58d1f1356df6a7d2de3f55bb665b18b04ffda0

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

The original Linux kernel CVE announcement for CVE-2026-72005 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-72005

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:L/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS score: 4.7

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: 0
  Paranoid ActionableScore: 2

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).