This indicates an attack attempt to exploit a Denial of Service Vulnerability in Linux Kernel.
The vulnerability is due to an error in the vulnerable application when handling a maliciously crafted tcp packet. A remote attacker may be able to exploit this to cause a denial of service condition on the affected system.
Linux Kernel Project Kernel mainline prior to 4.18-rc7
Denial of Service: Remote attackers can crash vulnerable systems.
Apply the most recent upgrade or patch from the vendor: