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.
Product status
04aae283ba6a8cd4851d937bf9c6d6ef0361d794 (git) before ed8c61b89be0c45f029228b2913d5cf7b5cda1a7
04aae283ba6a8cd4851d937bf9c6d6ef0361d794 (git) before a9c115e017b2c633d25bdfe6709dda6fc36f08c2
04aae283ba6a8cd4851d937bf9c6d6ef0361d794 (git) before bf40644ef8c8a288742fa45580897ed0e0289474
4.0
Any version before 4.0
6.12.64 (semver)
6.18.3 (semver)
6.19 (original_commit_for_fix)
References
git.kernel.org/...c/ed8c61b89be0c45f029228b2913d5cf7b5cda1a7
git.kernel.org/...c/a9c115e017b2c633d25bdfe6709dda6fc36f08c2
git.kernel.org/...c/bf40644ef8c8a288742fa45580897ed0e0289474