int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
		 unsigned int group, int report, gfp_t flags)
{
	int err = 0;

	if (group) {
		int exclude_portid = 0;

		if (report) {
			atomic_inc(&skb->users);
			exclude_portid = portid;
		}

		/* errors reported via destination sk->sk_err, but propagate
		 * delivery errors if NETLINK_BROADCAST_ERROR flag is set */
		err = nlmsg_multicast(sk, skb, exclude_portid, group, flags);
	}

	if (report) {
		int err2;

		err2 = nlmsg_unicast(sk, skb, portid);
		if (!err || err == -ESRCH)
			err = err2;
	}

	return err;
}

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.