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://bugzilla.redhat.com/show_bug.cgi?id=1078201
http://www.debian.org/security/2014/dsa-3044
http://rhn.redhat.com/errata/RHSA-2014-0421.html
http://rhn.redhat.com/errata/RHSA-2014-0420.html
http://git.qemu.org/?p=qemu.git%3Ba=commitdiff%3Bh=9302e863aa8baa5d932fc078967050c055fa1a7f
http://git.qemu.org/?p=qemu.git%3Ba=commitdiff%3Bh=8e53abbc20d08ae3ec30c2054e1161314ad9501d