static int complete_emulated_mmio(struct kvm_vcpu *vcpu)
{
	struct kvm_run *run = vcpu->run;
	struct kvm_mmio_fragment *frag;
	unsigned len;

	BUG_ON(!vcpu->mmio_needed);

	/* Complete previous fragment */
	frag = &vcpu->mmio_fragments[vcpu->mmio_cur_fragment];
	len = min(8u, frag->len);
	if (!vcpu->mmio_is_write)
		memcpy(frag->data, run->mmio.data, len);

	if (frag->len <= 8) {
		/* Switch to the next fragment. */
		frag++;
		vcpu->mmio_cur_fragment++;
	} else {
		/* Go forward to the next mmio piece. */
		frag->data += len;
		frag->gpa += len;
 		frag->len -= len;
 	}
 
	if (vcpu->mmio_cur_fragment == vcpu->mmio_nr_fragments) {
 		vcpu->mmio_needed = 0;
 
 		/* FIXME: return into emulator if single-stepping.  */
		if (vcpu->mmio_is_write)
			return 1;
		vcpu->mmio_read_completed = 1;
		return complete_emulated_io(vcpu);
	}

	run->exit_reason = KVM_EXIT_MMIO;
	run->mmio.phys_addr = frag->gpa;
	if (vcpu->mmio_is_write)
		memcpy(run->mmio.data, frag->data, min(8u, frag->len));
	run->mmio.len = min(8u, frag->len);
	run->mmio.is_write = vcpu->mmio_is_write;
	vcpu->arch.complete_userspace_io = complete_emulated_mmio;
	return 0;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.