int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
{
	struct kvm_memory_slot *memslot = gfn_to_memslot(kvm, gfn);

	if (!memslot || memslot->id >= KVM_USER_MEM_SLOTS ||
	      memslot->flags & KVM_MEMSLOT_INVALID)
		return 0;

	return 1;
}

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.