The serial_update_parameters function in hw/char/serial.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (divide-by-zero error and QEMU process crash) via vectors involving a value of divider greater than baud base.
git.qemu.org/?p=qemu.git%3Ba=commit%3Bh=3592fe0c919cf27a81d8e9f9b4f269553418bb01
lists.opensuse.org/opensuse-updates/2016-12/msg00140.html
www.openwall.com/lists/oss-security/2016/10/14/9
www.openwall.com/lists/oss-security/2016/10/15/5
www.securityfocus.com/bid/93563
access.redhat.com/errata/RHSA-2017:2392
access.redhat.com/errata/RHSA-2017:2408
lists.debian.org/debian-lts-announce/2018/09/msg00007.html
security.gentoo.org/glsa/201611-11