QEMU, possibly before 2.0.0, allows local users to cause a denial of service (divide-by-zero error and crash) via a zero value in the (1) tracks field to the seek_to_sector function in block/parallels.c or (2) extent_size field in the bochs function in block/bochs.c. https://nvd.nist.gov/vuln/detail/CVE-2014-0142