This indicates an attack attempt to exploit a Privilege Escalation vulnerability in Linux Kernel.
The vulnerability is due to an error when the vulnerable system handles reference in the keyrings facility. An attacker can exploit this to elevate their privileges on vulnerable systems.
Linux Kernel version 3.8 and higher
Privilege Escalation: Remote attackers can leverage their privilege on the vulnerable systems.
Currently we are unaware of any vendor supplied patch for this issue.