Amazon Linux AMI Security Advisory: ALAS-2012-100
Advisory Release Date: 2012-07-05 16:19 Pacific
Advisory Updated Date: 2014-09-14 16:33 Pacific
A flaw was found in the way the Linux kernel's Event Poll (epoll) subsystem handled large, nested epoll structures. A local, unprivileged user could use this flaw to cause a denial of service.
A malicious Network File System version 4 (NFSv4) server could return a crafted reply to a GETACL request, causing a denial of service on the client.
The rds_ib_xmit function in net/rds/ib_send.c in the Reliable Datagram Sockets (RDS) protocol implementation in the Linux kernel 3.7.4 and earlier allows local users to cause a denial of service (BUG_ON and kernel panic) by establishing an RDS connection with the source IP address equal to the IPoIB interface's own IP address, as demonstrated by rds-ping.
Run yum update kernel to update your system. You will need to reboot your system in order for the new kernel to be running.