This kernel update provides an update to 3.12.9 and fixes the following critical security issue:
Pageexec reported a bug in the Linux kernel's recvmmsg syscall when called from code using the x32 ABI. An unprivileged local user could exploit this flaw to cause a denial of service (system crash) or gain administrator privileges (CVE-2014-0038)
The -rt patch has been updated to -rt13.
For other changes, see the referenced changelog