The ohci_bus_start function in the USB OHCI emulation support (hw/usb/hcd-ohci.c) in QEMU allows local guest OS administrators to cause a denial of service (NULL pointer dereference and QEMU process crash) via vectors related to multiple eof_timers.<a href=http://cwe.mitre.org/data/definitions/476.html>CWE-476: NULL Pointer Dereference</a> http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-2391