CVE-2025-68822: Input: alps - fix use-after-free bugs caused by dev3_register_work

Vulnerability summary

CVE-2025-68822 is a high (CVSS 7.8) Use After Free vulnerability in linux. EPSS estimates a 0.18% chance of exploitation in the next 30 days, higher than 7.3% of scored vulnerabilities.

Timeline

1. 13-01-2026
   PublishedVulnerability first disclosed.
2. 30-10-2026
   Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: Input: alps - fix use-after-free bugs caused by dev3_register_work The dev3_register_work delayed work item is initialized within alps_reconnect() and scheduled upon receipt of the first bare PS/2 packet from an external PS/2 device connected to the ALPS touchpad. During device detachment, the original implementation calls flush_workqueue() in psmouse_disconnect() to ensure completion of dev3_register_work. However, the flush_workqueue() in psmouse_disconnect() only blocks and waits for work items that were already queued to the workqueue prior to its invocation. Any work items submitted after flush_workqueue() is called are not included in the set of tasks that the flush operation awaits. This means that after flush_workqueue() has finished executing, the dev3_register_work could still be scheduled. Although the psmouse state is set to PSMOUSE_CMD_MODE in psmouse_disconnect(), the scheduling of dev3_register_work remains unaffected. The race condition can occur as follows: CPU 0 (cleanup path) | CPU 1 (delayed work) psmouse_disconnect() | psmouse_set_state() | flush_workqueue() | alps_report_bare_ps2_packet() alps_disconnect() | psmouse_queue_work() kfree(priv); // FREE | alps_register_bare_ps2_mouse() | priv = container_of(work...); // USE | priv->dev3 // USE Add disable_delayed_work_sync() in alps_disconnect() to ensure that dev3_register_work is properly canceled and prevented from executing after the alps_data structure has been deallocated. This bug is identified by static analysis.

• CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.