Ubuntu Security Notice 2446-1 – An information leak in the Linux kernel was discovered that could leak the high 16 bits of the kernel stack address on 32-bit Kernel Virtual Machine (KVM) paravirt guests. A user in the guest OS could exploit this leak to obtain information that could potentially be used to aid in attacking the kernel. Rabin Vincent, Robert Swiecki, Russell King discovered that the ftrace subsystem of the Linux kernel does not properly handle private syscall numbers. A local user could exploit this flaw to cause a denial of service (OOPS). Various other issues were also addressed.