This indicates an attack attempt to exploit a Denial of Service vulnerability in Linux Kernel with UFO enabled.
The vulnerability is due to an error when vulnerable software handles a UDP packets over IPv6 with a size larger than MTU. A remote attacker may be able to exploit this to cause a denial of service condition on the affected system.
Linux Kernel Project Kernel from 3.10-rc5 prior to commit 0e033e04c2678 (mainline)
Denial of Service: Remote attackers can crash vulnerable systems or services
Apply the most recent upgrade or patch from the vendor.