Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

HID: bpf: abort dispatch if device destroyed

The current HID bpf implementation assumes no output report/request will go through it after hid_bpf_destroy_device() has been called. This leads to a bug that unplugging certain types of HID devices causes a cleaned- up SRCU to be accessed. The bug was previously a hidden failure until a recent x86 percpu change [1] made it access not-present pages.

The bug will be triggered if the conditions below are met:

A) a device under the driver has some LEDs on B) hid_ll_driver->request() is uninplemented (e.g., logitech-djreceiver)

If condition A is met, hidinput_led_worker() is always scheduled *after* hid_bpf_destroy_device().

hid_destroy_device ` hid_bpf_destroy_device ` cleanup_srcu_struct(&hdev->bpf.srcu) ` hid_remove_device ` ... ` led_classdev_unregister ` led_trigger_set(led_cdev, NULL) ` led_set_brightness(led_cdev, LED_OFF) ` ... ` input_inject_event ` input_event_dispose ` hidinput_input_event ` schedule_work(&hid->led_work) [hidinput_led_worker]

This is fine when condition B is not met, where hidinput_led_worker() calls hid_ll_driver->request(). This is the case for most HID drivers, which implement it or use the generic one from usbhid. The driver itself or an underlying driver will then abort processing the request.

Otherwise, hidinput_led_worker() tries hid_…