CVE-2026-80622 char: tlclk: fix use-after-free in tlclk_cleanup()
A use-after-free vulnerability in the Linux kernel tlclk driver allows attackers to execute arbitrary code or escalate privileges during module cleanup.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-80622?
CVE-2026-80622 is a high-severity use after free vulnerability in Linux, published on 28 Aug 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:
char: tlclk: fix use-after-free in tlclk_cleanup()
This patch improves the module cleanup process in the tlclk driver to prevent potential use-after-free and race conditions.
Currently, the file_operations structure does not specify the .owner field, which could allow the module to be unloaded while user-space processes are still interacting with the device. Additionally, the tlclk_cleanup() function frees the alarm_events memory before ensuring that blocked processes in the waitqueue are fully awakened and that the switchover_timer has completed.
To address these cases, this patch: - Sets '.owner = THIS_MODULE' in tlclk_fops to safely defer module unloading while the device is in use. - Updates tlclk_cleanup() to explicitly wake up all blocked readers (wake_up_all), properly release hardware I/O regions, and safely delete the timer (timer_delete_sync) prior to freeing memory.
Which versions are affected by CVE-2026-80622?
How do I fix CVE-2026-80622?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-80622 being exploited?
There is no known exploitation of CVE-2026-80622 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-80622, DEBIAN-CVE-2026-80622, GHSA-hhvf-97x6-wjfh, UBUNTU-CVE-2026-80622.