In the Linux kernel, the following vulnerability has been resolved:
HID: nintendo: register input device after capabilities are set
input_register_device() exposes the device to userspace immediately. In joycon_input_create() it was called before joycon_config_rumble() configures the FF_RUMBLE capability and the memless force-feedback device, so a concurrent EVIOCSFF could dereference a NULL dev->ff.
Registering early also means the initial udev event lacks button and axis information, which can make input managers ignore the device.
Move input_register_device() to the end of joycon_input_create(), after all capabilities, the IMU input device and the force-feedback callbacks have been configured.