Input: alps - fix use-after-free bugs caused by dev3_register_work
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.
02 / AFFECTED SOFTWARE
Affected packages
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
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.
05 / REFERENCES
Further evidence
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- https://git.kernel.org/stable/c/a9c115e017b2c633d25bdfe6709dda6fc36f08c2
- https://git.kernel.org/stable/c/bf40644ef8c8a288742fa45580897ed0e0289474
- https://git.kernel.org/stable/c/ed8c61b89be0c45f029228b2913d5cf7b5cda1a7
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/68xxx/CVE-2025-68822.json
- https://nvd.nist.gov/vuln/detail/CVE-2025-68822