[CVE-2026-64362][MODERATE 7.0] HID: lg-g15: cancel pending work on remove to fix a use-after-free

[CVE-2026-64362][MODERATE 7.0] HID: lg-g15: cancel pending work on remove to fix a use-after-free

[AL-KERNEL]

CVE: CVE-2026-64362
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: HID: lg-g15: cancel pending work on remove to fix a use-after-free
Commit: 3b9a3919aac6977262f04d5365c0456877522a44
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=3b9a3919aac6977262f04d5365c0456877522a44
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64362
Analysis date: Sat, 25 Jul 2026 07:52:43 -0400
ActionableScore: 5
ActionableScore lower bound: 3
Actionable bucket: Actionable Moderate at minimum
Manual review required: YES

Summary:
A race in the HID lg-g15 driver can leave scheduled work running after devm managed device state is freed on unplug, causing a kernel use after free and likely local or physical DoS, with manual review warranted for worst case UAF impact.

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

The original Linux kernel CVE announcement for CVE-2026-64362 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64362

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.

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AL-KERNEL CLASSIFICATION RESULT
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CVE-2026-64362	MODERATE	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:H/I:H/A:H';*CWE-416;CWE-362;*CWE-664;Other CVSS 'AV:P/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '7';DESCR 'A use after free can occur in the HID lg-g15 driver because lg_g15_data is devm managed and contains a work item that can remain pending after device removal. Report handlers can schedule this work from keyboard input, and if the device is unplugged before the worker is cancelled, devres may free lg_g15_data while the worker later dereferences it through container_of. The realistic impact is a local or physical denial of service via kernel crash. For the CVSS the PR:L is used for the paranoid score because a local user or reduced capability service that can cause HID device removal or USB rebind may trigger the race without full administrator privileges in some deployments. The issue is not network reachable. Because the primitive is a kernel UAF in a workqueue context, worst case impact may include confidentiality and integrity compromise and should be reviewed manually.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate at minimum (with actual score 4)	YES	USB INIT RACE UAF HARDWARE TEST  INCREASED_TO_MODERATE7_BASED_ON_GUESSCVSS DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5	NO	NO	checked

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

ActionableScore=5
ActionableScoreLower=3

## 1. ActionableScore

* Conservative score: 3
* Paranoid score: 5
* Final recommended bucket: **Actionable Moderate at minimum**

## 2. Signal breakdown

Conservative signals:

* Local or physical unprivileged trigger: +1. A local user with access to the affected Logitech HID device can generate the input event and race it with unplug or removal.
* Memory corruption, weak primitive: +1. This is a real UAF, but the patch only shows stale workqueue access after devm free, with no demonstrated reclaim, overwrite, type confusion, or attacker controlled replacement.
* Real lifetime corruption: +1. The bug is an async workqueue lifetime mismatch where devres frees `lg_g15_data` before pending work is cancelled.
* Reliable kernel crash or strong DoS: +1. A worker dereferencing freed driver state can realistically crash the kernel.
* Device specific and limited exposure: -1. The affected path requires specific Logitech G15/G15 v2/G510 style HID hardware or equivalent emulation.
* Race only UAF cap applies. Conservative handling should not upgrade this to strong LPE without reclaim, write after free, callback control, or type confusion evidence.

Paranoid signals:

* Same as conservative, plus weak UAF review concern: +1. The stale access occurs in kernel workqueue context after object free, so manual review is justified even though a practical LPE primitive is not demonstrated.
* Paranoid score remains capped at 5 under the race UAF downgrade rule.

Call-site confidence: high. The commit message identifies the scheduling sites, the freed object, the worker access pattern, and the missing remove callback.

## 3. Reachability analysis

The bug is not remotely network reachable. The realistic trigger requires an affected HID keyboard, an input event that schedules the work item, and a concurrent unplug or device removal before the work completes. A normal local user with physical access may be able to press the relevant key and unplug the device, while software-triggered remove or USB rebind paths usually require elevated privileges or delegated device-management rights. Containers normally do not expose raw USB device removal unless explicitly delegated.

## 4. Severity interpretation

This behaves above an ordinary Moderate because it is a real kernel UAF and not just a warning or leak. Realistic impact is mainly local or physical DoS via kernel crash. Theoretical privilege escalation is possible in the broad sense used for kernel UAF triage, but the patch does not show attacker-controlled reclaim, stale object replacement, write primitive, type confusion, or function pointer control. Therefore it is best treated as Actionable Moderate at minimum rather than a strong Important candidate.

## 5. One-sentence report phrase

A race in the HID lg-g15 driver can leave scheduled work running after devm managed device state is freed on unplug, causing a kernel use after free and likely local or physical DoS, with manual review warranted for worst case UAF impact.

## 6. Manual review recommendation

MANUAL CHECK REQUIRED

This is a race-based kernel UAF in a workqueue lifetime path. Even though practical exploitation beyond DoS is not demonstrated and exposure is device-specific, UAF bugs should not be auto-closed without review.

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

Patch: HID: lg-g15: cancel pending work on remove to fix a use-after-free
Commit: 3b9a3919aac6977262f04d5365c0456877522a44
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=3b9a3919aac6977262f04d5365c0456877522a44

Commit description:

lg_g15_data is allocated with devm and holds a work item. The report
handlers schedule that work straight from device input.
lg_g15_event() and lg_g15_v2_event() do it on the backlight cycle key,
and lg_g510_leds_event() does it too. The worker dereferences the
lg_g15_data back through container_of.

The driver had no remove callback and never cancelled the work. So if a
report scheduled the work and the keyboard was then unplugged, devres
freed lg_g15_data while the work was still pending or running, and the
worker touched freed memory. This is a use-after-free. It is reachable
as a race on device unplug.

Add a remove callback that cancels the work before devres frees the
state. g15->work is only initialized for the models that schedule it
(G15, G15 v2, G510). The G13 and Z-10 leave it zeroed, so guard the
cancel on g15->work.func to avoid cancelling a work that was never set
up. The g15 NULL test mirrors the one already in lg_g15_raw_event().

Fixes: 97b741a ("HID: lg-g15: Add keyboard and LCD backlight control")
Cc: stable@vger.kernel.org
Suggested-by: Hans de Goede <hansg@kernel.org>
Signed-off-by: Maoyi Xie <maoyixie.tju@gmail.com>
Reviewed-by: Hans de Goede <johannes.goede@oss.qualcomm.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  drivers/hid/hid-lg-g15.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=3b9a3919aac6977262f04d5365c0456877522a44

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

The original Linux kernel CVE announcement for CVE-2026-64362 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64362

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:P/AC:H/PR:N/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:H/I:H/A:H
  The Best / paranoid CVSS score: 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: 3
  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: NO
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).