The address_space_write_continue function in exec.c in QEMU (aka Quick Emulator) allows local guest OS privileged users to cause a denial of service (out-of-bounds access and guest instance crash) by leveraging use of qemu_map_ram_ptr to access guest ram block area.
https://usn.ubuntu.com/3575-1/
https://lists.gnu.org/archive/html/qemu-devel/2017-07/msg03775.html
https://bugzilla.redhat.com/show_bug.cgi?id=1471638
https://access.redhat.com/errata/RHSA-2017:3474
https://access.redhat.com/errata/RHSA-2017:3473
https://access.redhat.com/errata/RHSA-2017:3472
https://access.redhat.com/errata/RHSA-2017:3471
https://access.redhat.com/errata/RHSA-2017:3470
https://access.redhat.com/errata/RHSA-2017:3466
https://access.redhat.com/errata/RHSA-2017:3369
http://www.securityfocus.com/bid/99895