The pnv_lpc_do_eccb function in hw/ppc/pnv_lpc.c in Qemu before 3.1 allows out-of-bounds write or read access to PowerNV memory.
https://www.debian.org/security/2019/dsa-4454
https://usn.ubuntu.com/3826-1/
https://seclists.org/bugtraq/2019/May/76
https://lists.gnu.org/archive/html/qemu-devel/2018-11/msg00446.html
http://www.securityfocus.com/bid/105920
http://www.openwall.com/lists/oss-security/2018/11/06/6
http://lists.opensuse.org/opensuse-security-announce/2019-03/msg00042.html