usb: gadget: uvc: clamp SEND_RESPONSE length to the response buffer

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: uvc: clamp SEND_RESPONSE length to the response buffer uvc_send_response() builds the UVC control response from a user-supplied struct uvc_request_data: req->length = min_t(unsigned int, uvc->event_length, data->length); ... memcpy(req->buf, data->data, req->length); req->length is clamped to uvc->event_length, which is taken from the host control request wLength (up to UVC_MAX_REQUEST_SIZE, 64), and to data->length, which comes from the UVCIOC_SEND_RESPONSE ioctl and is only checked for being negative. The source buffer data->data is only 60 bytes, so a response with uvc->event_length and data->length both greater than 60 makes memcpy() read past the end of data->data. Clamp req->length to sizeof(data->data) as well.