CVE-2026-31720 usb: gadget: f_uac1_legacy: validate control request size

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: fuac1legacy: validate control request size faudiocomplete copies req-length bytes into a 4-byte stack variable: u32 data = 0; memcpy&data, req-buf, req-length; req-length is derived from the host-controlled USB reque...