The MITRE CVE dictionary describes this issue as:
The restore_fpu_checking function in arch/x86/include/asm/fpu-internal.h in the Linux kernel before 3.12.8 on the AMD K7 and K8 platforms does not clear pending exceptions before proceeding to an EMMS instruction, which allows local users to cause a denial of service (task kill) or possibly gain privileges via a crafted application.
Find out more about CVE-2014-1438 from the
MITRE CVE dictionary dictionary and
This issue does not affect the versions of Linux kernel as shipped with Red Hat Enterprise Linux 5 and Red Hat Enterprise Linux 6.