CVE-2025-68822
7.8
Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Exploitability: 1.8 / Impact: 5.9
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary)
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.
References (5)
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Timeline
No history available yet.