The ne2000_receive function in the NE2000 NIC emulation support (hw/net/ne2000.c) in QEMU before 2.5.1 allows local guest OS administrators to cause a denial of service (infinite loop and QEMU process crash) via crafted values for the PSTART and PSTOP registers, involving ring buffer control.
git.qemu.org/?p=qemu.git%3Ba=commit%3Bh=415ab35a441eca767d033a2702223e785b9d5190
lists.nongnu.org/archive/html/qemu-stable/2016-03/msg00064.html
www.openwall.com/lists/oss-security/2016/03/02/8
www.securityfocus.com/bid/84028
www.ubuntu.com/usn/USN-2974-1
bugzilla.redhat.com/show_bug.cgi?id=1303106
lists.debian.org/debian-lts-announce/2018/11/msg00038.html
lists.gnu.org/archive/html/qemu-devel/2016-02/msg06126.html
security.gentoo.org/glsa/201609-01