The skb_flow_dissect function in net/core/flow_dissector.c in the Linux kernel through 3.12 allows remote attackers to cause a denial of service (infinite loop) via a small value in the IHL field of a packet with IPIP encapsulation.
https://bugzilla.redhat.com/show_bug.cgi?id=1007939
http://www.ubuntu.com/usn/USN-2075-1
http://www.ubuntu.com/usn/USN-2070-1
http://rhn.redhat.com/errata/RHSA-2013-1490.html
http://lists.opensuse.org/opensuse-security-announce/2014-02/msg00002.html