After doing a little more investigation, it looks like there are other distributions that are having problems with vsftpd running on AWS EC2 instances.
It sounds like it may be related to a kernel bug that affect Xen paravirtualized hosts.
http://www.gossamer-threads.com/lists/linux/kernel/1854156?search_string=%5BBISECTED%5D%20Linux%203.12.7%20introduces%20page%20map%20handling%20regression;#1854156
After doing a little more investigation, it looks like there are other distributions that are having problems with vsftpd running on AWS EC2 instances.
It sounds like it may be related to a kernel bug that affect Xen paravirtualized hosts.
http:// www.gossamer- threads. com/lists/ linux/kernel/ 1854156? search_ string= %5BBISECTED% 5D%20Linux% 203.12. 7%20introduces% 20page% 20map%20handlin g%20regression; #1854156