Red Hat Security Advisory 2015-1221-01 – The kernel packages contain the Linux kernel, the core of any Linux operating system. A NULL pointer dereference flaw was found in the way the Linux kernel’s virtual console implementation handled reference counting when accessing pseudo-terminal device files. A local, unprivileged attacker could use this flaw to crash the system. It was found that the Linux kernel’s ping socket implementation did not properly handle socket unhashing during spurious disconnects, which could lead to a use-after-free flaw. On x86-64 architecture systems, a local user able to create ping sockets could use this flaw to crash the system. On non-x86-64 architecture systems, a local user able to create ping sockets could use this flaw to escalate their privileges on the system.