The vga display update in mis-calculated the region for the dirty bitmap snapshot in case split screen mode is used causing a denial of service (assertion failure) in the cpu_physical_memory_snapshot_get_dirty function.
lists.opensuse.org/opensuse-security-announce/2019-03/msg00042.html
www.openwall.com/lists/oss-security/2017/09/10/1
www.securityfocus.com/bid/100527
access.redhat.com/errata/RHSA-2018:1104
access.redhat.com/errata/RHSA-2018:1113
git.qemu.org/gitweb.cgi?p=qemu.git%3Ba=commit%3Bh=bfc56535f793c557aa754c50213fc5f882e6482d
lists.gnu.org/archive/html/qemu-devel/2017-08/msg04685.html