ioeventfd_write(struct kvm_vcpu *vcpu, struct kvm_io_device *this, gpa_t addr,
		int len, const void *val)
{
	struct _ioeventfd *p = to_ioeventfd(this);

	if (!ioeventfd_in_range(p, addr, len, val))
		return -EOPNOTSUPP;

	eventfd_signal(p->eventfd, 1);
	return 0;
}

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.