The kvm_set_msr_common function in arch/x86/kvm/x86.c in the Linux kernel through 3.8.4 does not ensure a required time_page alignment during an MSR_KVM_SYSTEM_TIME operation, which allows guest OS users to cause a denial of service (buffer overflow and host OS memory corruption) or possibly have unspecified other impact via a crafted application.
Improper Restriction of Operations within the Bounds of a Memory Buffer The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary.