A certain Red Hat patch for the Linux kernel 2.6.32 on Red Hat Enterprise Linux (RHEL) 6 allows local users to cause a denial of service (invalid free operation and system crash) or possibly gain privileges via a sendmsg system call with the IP_RETOPTS option, as demonstrated by hemlock.c. NOTE: this vulnerability exists because of an incorrect fix for CVE-2012-3552.
https://bugzilla.redhat.com/show_bug.cgi?id=979936
http://www.openwall.com/lists/oss-security/2013/06/30/7
http://rhn.redhat.com/errata/RHSA-2013-1450.html