Stack-based buffer overflow in the getaddrinfo function in sysdeps/posix/getaddrinfo.c in GNU C Library (aka glibc or libc6) 2.18 and earlier allows remote attackers to cause a denial of service (crash) via a (1) hostname or (2) IP address that triggers a large number of AF_INET6 address results.  NOTE: this vulnerability exists because of an incomplete fix for CVE-2013-1914.