Use-after-free vulnerability in arch/x86/kvm/x86.c in the Linux kernel through 3.8.4 allows guest OS users to cause a denial of service (host OS memory corruption) or possibly have unspecified other impact via a crafted application that triggers use of a guest physical address (GPA) in (1) movable or (2) removable memory during an MSR_KVM_SYSTEM_TIME kvm_set_msr_common operation.