CVE-2026-31667

/// Technical description

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

Input: uinput - fix circular locking dependency with ff-core

A lockdep circular locking dependency warning can be triggered

reproducibly when using a force-feedback gamepad with uinput (for

example, playing ELDEN RING under Wine with a Flydigi Vader 5

controller):

ff->mutex -> udev->mutex -> input_mutex -> dev->mutex -> ff->mutex

The cycle is caused by four lock acquisition paths:

1. ff upload: input_ff_upload() holds ff->mutex and calls

uinput_dev_upload_effect() -> uinput_request_submit() ->

uinput_request_send(), which acquires udev->mutex.

2. device create: uinput_ioctl_handler() holds udev->mutex and calls

uinput_create_device() -> input_register_device(), which acquires

input_mutex.

3. device register: input_register_device() holds input_mutex and

calls kbd_connect() -> input_register_handle(), which acquires

dev->mutex.

4. evdev release: evdev_release() calls input_flush_device() unde

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References