[CVE-2026-80767][MODERATE 7.0] HID: sensor: custom: Fix use-after-free in enable_sensor

[CVE-2026-80767][MODERATE 7.0] HID: sensor: custom: Fix use-after-free in enable_sensor

[AL-KERNEL]

CVE: CVE-2026-80767
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: HID: sensor: custom: Fix use-after-free in enable_sensor
Commit: c2be74b0272b7f8f60739e7aaf0d36c0befe7136
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c2be74b0272b7f8f60739e7aaf0d36c0befe7136
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80767
Analysis date: Fri, 04 Sep 2026 12:34:56 -0400
ActionableScore: 5
ActionableScore lower bound: 3
Actionable bucket: Actionable Moderate at minimum
Manual review required: YES

Summary:
No one-sentence report phrase was found.

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

The original Linux kernel CVE announcement for CVE-2026-80767 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80767

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-2026-80767	MODERATE	https://www.kernelcve.org/list/?q=CVE-2026-80767 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-367;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '7';DESCR 'HID sensor custom exposes an enable_sensor sysfs attribute that can call set_power_report_state and dereference sensor_inst power_state and report_state. These pointers refer to entries in sensor_inst fields, so accessing enable_sensor before field state is initialized or while field attributes are being removed can lead to a use-after-free. A local attacker with access to the sysfs attribute could try to race probe or remove paths and trigger a kernel crash. For the CVSS the PR:L is used for the paranoid score because some deployments may delegate sensor sysfs access to non-root users or service accounts even though default sysfs writes are often administrator controlled. The issue is not network reachable. Impact is at least local denial of service and in worst case may allow confidentiality or integrity impact due to kernel UAF memory corruption, so it should be reviewed manually.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate at minimum (with actual score 4)	YES	DANGER USB UAF KPANIC  KPANIC INCREASED_TO_HIGH_BASED_ON_GUESSCVSS KPANIC DECREASED_TO_MODERATE70_BASED_ON_ACTIONABLESCORELOWERTHAN5	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**
* Local trigger: +1 in the paranoid interpretation because `enable_sensor` is a sysfs write path and may be delegated by permissions, udev rules, service accounts, or device-management stacks.
* Memory corruption, weak primitive: +1 because the patch explicitly fixes a UAF through `power_state` or `report_state`, but does not show attacker-controlled reclaim, overwrite, callback control, or type confusion.
* Real lifetime corruption: +1 because the bug is caused by incorrect lifetime ordering between sysfs exposure/removal and freeing field attributes.
* Reliable kernel crash / strong DoS: +1 because dereferencing freed state from a sysfs write can plausibly crash the kernel.
* Privileged/device-management lifetime path: +1 because the issue occurs in HID sensor probe/remove and sysfs device-management ordering.
* Hard or unreliable race / special timing: -1 because practical triggering requires racing sysfs access against probe failure or device removal.
* Typical admin gating: conservative handling keeps the lower score at 3 because default sysfs write/remove control is often administrator-controlled, but not always equivalent to full host-root in real deployments.

3. **Reachability analysis**
A local actor who can write the HID sensor `enable_sensor` sysfs attribute can reach the vulnerable path. Reliable triggering also depends on timing against initialization or removal, so this is not a simple single-call bug. The issue is not network reachable. Containers and namespaces do not normally expose this device sysfs path safely by default, but delegated device access, udev permissions, desktop sensor services, or reduced-privilege service accounts can make PR:L a defensible paranoid interpretation.

4. **Severity interpretation**
This is not an ordinary resource leak or validation-only bug. It is a real kernel UAF, but the demonstrated primitive is a stale pointer dereference rather than controlled reuse or overwrite. Realistic impact is local DoS. Theoretical LPE concern exists because UAFs can sometimes become exploitable, but the patch does not show a strong reclaim or write primitive. Therefore it is best treated as Actionable Moderate at minimum, with manual review required.

5. **One-sentence report phrase**
A UAF in HID sensor custom sysfs handling can occur when `enable_sensor` races with field attribute initialization or removal, allowing a local actor with access to the sysfs attribute to dereference freed `power_state` or `report_state` memory and potentially crash the kernel.

6. **Manual review recommendation**
MANUAL CHECK REQUIRED. The patch explicitly fixes a UAF in a writable sysfs path, and although the practical evidence points mainly to DoS, lifetime bugs of this class should not be auto-closed without checking permissions, reachable devices, and whether any controlled reuse primitive exists.

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

Patch: HID: sensor: custom: Fix use-after-free in enable_sensor
Commit: c2be74b0272b7f8f60739e7aaf0d36c0befe7136
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c2be74b0272b7f8f60739e7aaf0d36c0befe7136

Commit description:

enable_sensor_store() can call set_power_report_state(), which
dereferences sensor_inst->power_state and sensor_inst->report_state.
These pointers refer to entries in sensor_inst->fields.

Create the field attributes before exposing the enable_sensor sysfs
attribute, so enable_sensor cannot be accessed before the state it
depends on has been initialized.

On remove, delete enable_sensor before freeing the field attributes,
so a concurrent sysfs write cannot dereference freed memory through
power_state or report_state.

Reported-by: Sashiko AI Review <sashiko-bot@kernel.org>
Link: https://sashiko.dev/#/patchset/20260623021950.1736413-1-haoxiang_li2024@163.com?part=1
Fixes: 4a7de05 ("HID: sensor: Custom and Generic sensor support")
Cc: stable@vger.kernel.org
Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  drivers/hid/hid-sensor-custom.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=c2be74b0272b7f8f60739e7aaf0d36c0befe7136

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

The original Linux kernel CVE announcement for CVE-2026-80767 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80767

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: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: 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).