---
id: CVE-2026-64365
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  HID: letsketch: fix UAF on inrange_timer at driver unbind

  letsketch_driver does not provide a .remove callback, but
  letsketch_probe() arms a per-device timer:

      tim…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  HID: letsketch: fix UAF on inrange_timer at driver unbind

  letsketch_driver does not provide a .remove callback, but
  letsketch_probe() arms a per-device timer:

      tim…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-416
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 5.17, < 6.1.178'
  - 'linux_kernel >= 6.2, < 6.6.145'
  - 'linux_kernel >= 6.7, < 6.12.96'
  - 'linux_kernel >= 6.13, < 6.18.39'
  - 'linux_kernel >= 6.19, < 7.1.4'
  - linux_kernel = 7.2
patched:
  - linux_kernel 7.1.4
published: '2026-07-25'
updated: '2026-09-04'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-64365'
references:
  - url: 'https://git.kernel.org/stable/c/17f5928d7010bc9e002930326b59e60e40c09ee3'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/2bb6e7143cf70ed281822d26c1848b2897ac36e9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/3eca1a8165b5e7996e699e9df76cb4645e184d42'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/46c8beeccd8ab2c863827254a85ea877654a3534'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/523db788c0f84612707638e266e8957ca7e3a756'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/df3d8aa1a9392da3de66398e7a03422463806b21'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00129
epssPercentile: 0.02115
ingestedAt: '2026-09-05T13:39:57.039Z'
---

## Overview

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

HID: letsketch: fix UAF on inrange_timer at driver unbind

letsketch_driver does not provide a .remove callback, but
letsketch_probe() arms a per-device timer:

    timer_setup(&data->inrange_timer, letsketch_inrange_timeout, 0);

The timer is re-armed from letsketch_raw_event() with a 100 ms
timeout on every pen-in-range report, and its callback dereferences
data->input_tablet to deliver a synthetic BTN_TOOL_PEN release.

letsketch_data is allocated with devm_kzalloc(), and its input_dev
fields are devm-allocated via letsketch_setup_input_tablet().  On
device unbind (USB unplug or rmmod), the HID core runs its default
teardown and devm cleanup frees both letsketch_data and the input
devices.  Because no .remove callback exists, nothing drains the
timer first: if raw_event armed it within ~100 ms of the unbind,
the pending timer fires on freed memory.  This is a UAF read of
data and of data->input_tablet, followed by input_report_key() /
input_sync() into the freed input_dev.

The same problem can occur on the probe error path: if
hid_hw_start() enabled I/O on an always-poll-quirk device and then
failed, raw_event may have armed the timer before devm releases
data.

Fix by adding a .remove callback that calls hid_hw_stop() first.
hid_hw_stop() synchronously kills the URBs that deliver raw_event(),
so once it returns no path can re-arm the timer.  timer_shutdown_sync()
then drains any in-flight callback and permanently disables further
mod_timer() calls.  Apply the same timer_shutdown_sync() in the probe
error path so the timer is guaranteed not to outlive data.

## Affected

- `linux_kernel >= 5.17, < 6.1.178`
- `linux_kernel >= 6.2, < 6.6.145`
- `linux_kernel >= 6.7, < 6.12.96`
- `linux_kernel >= 6.13, < 6.18.39`
- `linux_kernel >= 6.19, < 7.1.4`
- `linux_kernel = 7.2`

## Remediation

Upgrade past the affected range:

- `linux_kernel 7.1.4`