An infinite loop issue was found in the USB OHCI controller emulator of QEMU before version 5.2.0. It could occur while servicing OHCI isochronous transfer descriptors (TD) in ohci_service_iso_td routine, as it retires a TD if it has passed its time frame. While doing so it does not check if the TD was already processed ones and holds an error code in TD_CC. It may happen if the TD list has a loop.
A guest user/process may use this flaw to consume cpu cycles on the host resulting in a DoS scenario.