[CVE-2026-74441][MODERATE 7.0] usb: typec: ucsi: Fix race condition and ordering in port unregistration [ Upstream

[CVE-2026-74441][MODERATE 7.0] usb: typec: ucsi: Fix race condition and ordering in port unregistration [ Upstream

[AL-KERNEL]

CVE: CVE-2026-74441
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: usb: typec: ucsi: Fix race condition and ordering in port unregistration [ Upstream
Commit: 07f8aaffee705e552c1f723ac8bf7eb137ad59c2
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=07f8aaffee705e552c1f723ac8bf7eb137ad59c2
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74441
Analysis date: Sat, 15 Aug 2026 17:37:48 -0400
ActionableScore: 5
ActionableScore lower bound: 4
Actionable bucket: Actionable Moderate at minimum
Manual review required: YES

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-74441 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74441

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: MODERATE 7.0
Manual review required: YES

A detailed explanation of the methodology and priority rules is included
at the end of this message.

======================================================================
AL-KERNEL CLASSIFICATION RESULT
======================================================================

CVE-2026-74441	MODERATE	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:L/UI:N/S:U/C:L/I:L/A:H';CWE-362;*CWE-416;CWE-415;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '5.8';DESCR 'A race in the USB Type-C UCSI port teardown path can allow pending partner delayed work to run or be queued while connector resources and the workqueue are being unregistered. This can lead to use-after-free or double release behavior, with observed crashes in __queue_work and ucsi_poll_worker. For the CVSS the PR:L is used in the paranoid score because a local user or reduced capability device management context may be able to influence Type-C or UCSI lifecycle events, although reliable driver teardown is often administrator controlled. The issue is not network reachable and is triggered through local device lifecycle, error path, or unregistration conditions rather than packet traffic. Impact is at least local denial of service via kernel crash and in worst case may allow limited confidentiality or integrity impact due to memory corruption and should be reviewed manually.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate at minimum (with actual score 5)	YES	OOB LOCK DANGER NULLPTR USB INIT RACE ERRORPATH UAF IMPROVEONLY KERNEL_PANIC_PLUS_UAF LINUS KPANIC 	NO	NO	checked

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

ActionableScore=5
ActionableScoreLower=4

1. ActionableScore
* Conservative score: 4
* Paranoid score: 5
* Final recommended bucket: **Actionable Moderate at minimum**::

2. Signal breakdown
* Firmware-mediated external influence: +1. UCSI behavior depends on Type-C controller or EC or PPM lifecycle events, and the shown failure includes PPM init timeout.
* Memory corruption, weak/indirect corruption candidate: +1. The patch and commit explicitly mention UAF conditions and double release, but no controlled reclaim, overwrite, callback control, or object replacement is shown.
* Real lifetime corruption: +1. Pending delayed work can outlive connector or workqueue teardown and run against freed or invalid resources.
* Reliable kernel crash / strong DoS: +1. The commit includes observed NULL dereference in __queue_work and GPF in ucsi_poll_worker.
* Privileged kernel/device-management lifetime path: +1. The bug is in USB Type-C UCSI teardown and workqueue lifecycle management.
* Hard or unreliable race / special timing required: -1. Triggering depends on ordering between delayed work, partner unregistration, and workqueue destruction.
* Conservative privilege penalty refinement: -1. Reliable teardown is often administrator or driver lifecycle controlled, but init error paths and device or firmware mediated events make full -2 too harsh.

Paranoid delta:
* Local unprivileged trigger: +1. A local user or reduced device-management context may be able to influence Type-C attach, detach, role, or error-path behavior, even if reliable module or device teardown is usually privileged. This raises the score from 4 to 5.

3. Reachability analysis
The bug is not network reachable. It is triggered through local USB Type-C UCSI lifecycle, init error, partner task, or port unregistration paths. In typical deployments, direct driver unregister or teardown is privileged, but physical Type-C events, EC firmware behavior, or reduced-capability device-management services may influence the timing. Namespace effects are limited because this is a host device-management path rather than a per-netns or container-local interface. The affected subsystem is common on modern laptops and USB-C systems, but the exact trigger requires UCSI hardware and a teardown or error ordering window.

Call-site confidence: high. The patch shows both ucsi_init error cleanup and ucsi_unregister using the new ucsi_unregister_port helper, and the commit provides concrete crash traces.

4. Severity interpretation
This is stronger than an ordinary Moderate because the patch fixes an explicit race with UAF and double-release symptoms in a kernel workqueue teardown path. Realistic evidence points mainly to local or firmware-mediated denial of service, not a demonstrated LPE primitive. Theoretical memory corruption potential exists because stale delayed work can run after resource teardown, but the patch does not show attacker-controlled reclaim, arbitrary write, callback control, or stable object replacement. Therefore it is best treated as Actionable Moderate at minimum, with manual review recommended rather than auto-close.

5. One-sentence report phrase
A race in USB Type-C UCSI port teardown can allow pending partner delayed work to run during or after workqueue and connector cleanup, causing UAF or double-release crashes, with practical impact mainly local or firmware-mediated DoS and no direct network reachability.

6. Manual review recommendation
MANUAL CHECK REQUIRED. The commit explicitly describes UAF conditions and double release with observed crashes, and although exploitation beyond DoS is not demonstrated, lifetime corruption in asynchronous workqueue teardown should not be auto-closed.

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

Patch: usb: typec: ucsi: Fix race condition and ordering in port unregistration [ Upstream
Commit: 07f8aaffee705e552c1f723ac8bf7eb137ad59c2
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=07f8aaffee705e552c1f723ac8bf7eb137ad59c2

Changed files:
  drivers/usb/typec/ucsi/ucsi.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=07f8aaffee705e552c1f723ac8bf7eb137ad59c2

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

The original Linux kernel CVE announcement for CVE-2026-74441 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74441

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:H
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H
  The Best / paranoid CVSS score: 5.8

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: 4
  Paranoid ActionableScore: 5

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: MODERATE
KPANIC detected for this report: YES
Published priority for this report (same as in Subject): MODERATE 7.0

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).