# CVE-2026-80766: HID: uclogic: fix use-after-free of inrange_timer on remove

> A use-after-free in the Linux kernel uclogic HID driver allows local attackers to execute code or crash the system via race conditions during device removal.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 4 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-99513, BELL-CVE-2026-80766, DEBIAN-CVE-2026-80766, GHSA-xc7g-5f4m-53h6, UBUNTU-CVE-2026-80766

## What is CVE-2026-80766?

CVE-2026-80766 is an use after free vulnerability in Linux, published on 4 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

HID: uclogic: fix use-after-free of inrange_timer on remove

uclogic_remove() cancels the pen in-range timer and then stops the
device:

	timer_delete_sync(&drvdata->inrange_timer);
	hid_hw_stop(hdev);

timer_delete_sync() only guarantees the timer is idle at that instant.
uclogic_raw_event_pen() keeps delivering pen reports until hid_hw_stop()
stops the transport several lines later, and every report with
pen->inrange == UCLOGIC_PARAMS_PEN_INRANGE_NONE re-arms the timer:

	mod_timer(&drvdata->inrange_timer, jiffies + msecs_to_jiffies(100));

A report landing between the timer_delete_sync() call and the transport
teardown in hid_hw_stop() re-arms inrange_timer after it was cancelled.
uclogic_remove() then returns and the devm drvdata is freed, while
hid_hw_stop() has already freed the input device drvdata->pen_input
points at, so when the timer fires ~100 ms later
uclogic_inrange_timeout() dereferences freed memory -- a use-after-free
in timer-softirq context.

Swapping the two calls is not a fix: stopping the device first frees
drvdata->pen_input via hidinput_disconnect() while the timer may still
be pending, so a timer already armed before removal fires on the freed
input device in the window before timer_delete_sync() runs.

Use timer_shutdown_sync() before hid_hw_stop() instead. It cancels the
timer, waits for a running callback while pen_input is still valid, and
prevents any further re-arming -- a later mod_timer() from an in-flight
report is silently ignored -- so the timer is provably dead before
hid_hw_stop() frees the inputs. This is the ordering the timer core
documents for this "timer re-armed from another path" teardown case.

## Which versions are affected by CVE-2026-80766?


## How do I fix CVE-2026-80766?

Apply the vendor's patch.

## Is CVE-2026-80766 being exploited?

There is no known exploitation of CVE-2026-80766 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80766 and fix it if it is affected.

What it is: CVE-2026-80766 is an use after free vulnerability in Linux, published on 4 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-80766 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-80766/ (Markdown: https://insights.sbomify.com/CVE-2026-80766/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80766
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80766
- OSV: https://osv.dev/vulnerability/CVE-2026-80766

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80766/
Summaries are generated and may contain mistakes; the official description above is the record.