这个bug在去年最初报出来是作为crash问题报的，当时没有深究背后的远程代码执行的可能性。后来Google的工程师偶然发现这个问题，深究后发现问题不是crash那么简单 https://googleonlinesecurity.blogspot.com/2016/02/cve-2015-7547-glibc-getaddrinfo-stack.html
The glibc DNS client side resolver is vulnerable to a stack-based buffer overflow when the getaddrinfo() library function is used. Software using this function may be exploited with attacker-controlled domain names, attacker-controlled DNS servers, or through a man-in-the-middle attack.