Use After Free Affecting linux-6.12 package, versions <6.12.100-1~deb12u1


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.13% (3rd percentile)

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  • Snyk IDSNYK-ECHOLATEST-LINUX612-18579214
  • published7 Aug 2026
  • disclosed25 Jul 2026

Introduced: 25 Jul 2026

CVE-2026-64365  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Echo:latest linux-6.12 to version 6.12.100-1~deb12u1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream linux-6.12 package and not the linux-6.12 package as distributed by Echo. See How to fix? for Echo:latest relevant fixed versions and status.

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(&amp;data-&gt;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.

CVSS Base Scores

version 3.1