kernel: netfilter: nf_conntrack_dccp: incorrect skb_header_pointer API usages

net/netfilter/nfconntrackprotodccp.c in the Linux kernel through 3.13.6 uses a DCCP header pointer incorrectly, which allows remote attackers to cause a denial of service system crash or possibly execute arbitrary code via a DCCP packet that triggers a call to the 1 dccpnew, 2 dccppacket, or 3...