qemu/kvm: i8254: out-of-bounds memory access in pit_ioport_read function

An out-of-bounds memory access flaw, leading to memory corruption or possibly an information leak, was found in QEMU's pitioportread function. A privileged guest user in a QEMU guest, which had QEMU PIT emulation enabled, could potentially, in rare cases, use this flaw to execute arbitrary code o...