Bug 2429053 (CVE-2025-68822) - CVE-2025-68822 kernel: Input: alps - fix use-after-free bugs caused by dev3_register_work
Summary: CVE-2025-68822 kernel: Input: alps - fix use-after-free bugs caused by dev3_r...
Keywords:
Status: NEW
Alias: CVE-2025-68822
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-01-13 16:03 UTC by OSIDB Bzimport
Modified: 2026-02-12 19:15 UTC (History)
0 users

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Description OSIDB Bzimport 2026-01-13 16:03:19 UTC
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.


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