Ubuntu Security Notice 2871-1 - Yevgeny Pats discovered that the session keyring implementation in the Linux kernel did not properly reference count when joining an existing session keyring. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code with administrative privileges.
501ed51a6721237df848ea649c0e18ce7f231c00cd6ce10e71e27e1032f404dc