The skb argument to cipso_v4_validate() is NULL when called via the setsockopt() syscall. An local user able to set CIPSO IP options on the socket could use this flaw to crash the system.
This issue did affect the version of Linux kernel as shipped with Red Hat Enterprise Linux 6.
This issue did not affect the version of Linux kernel as shipped with Red Hat Enterprise Linux 5 and Red Hat Enterprise MRG 2.
This issue has been addressed in following products:
Red Hat Enterprise Linux 6
Via RHSA-2013:0496 https://rhn.redhat.com/errata/RHSA-2013-0496.html