The MITRE CVE dictionary describes this issue as:
The __request_module function in kernel/kmod.c in the Linux kernel before 3.4 does not set a certain killable attribute, which allows local users to cause a denial of service (memory consumption) via a crafted application.
Find out more about CVE-2012-4398 from the
MITRE CVE dictionary dictionary and
This issue does affect the versions of the Linux kernel as shipped with Red
Hat Enterprise Linux 5, 6 and Red Hat Enteprise MRG. Future kernel updates may address this flaw.