X.org libXi before 1.7.7 allows remote X servers to cause a denial of service (infinite loop) via vectors involving length fields.
https://security.gentoo.org/glsa/201704-03
https://lists.x.org/archives/xorg-announce/2016-October/002720.html
https://cgit.freedesktop.org/xorg/lib/libXi/commit/?id=19a9cd607de73947fcfb104682f203ffe4e1f4e5
http://www.securitytracker.com/id/1036945
http://www.securityfocus.com/bid/93374