void ipc_rcu_putref(void *ptr)
{
	if (--container_of(ptr, struct ipc_rcu_hdr, data)->refcount > 0)
		return;

	if (container_of(ptr, struct ipc_rcu_hdr, data)->is_vmalloc) {
		call_rcu(&container_of(ptr, struct ipc_rcu_grace, data)->rcu,
				ipc_schedule_free);
	} else {
		kfree_rcu(container_of(ptr, struct ipc_rcu_grace, data), rcu);
	}
}
Weaknesses in this category are related to improper calculation or conversion of numbers.