void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
{
	struct net_device *dev = skb->dev;
	struct netdev_queue *txq;
	bool free_skb = true;
	int cpu, rc;

	txq = netdev_pick_tx(dev, skb, NULL);
	cpu = smp_processor_id();
	HARD_TX_LOCK(dev, txq, cpu);
	if (!netif_xmit_stopped(txq)) {
		rc = netdev_start_xmit(skb, dev, txq, 0);
		if (dev_xmit_complete(rc))
			free_skb = false;
	}
	HARD_TX_UNLOCK(dev, txq);
	if (free_skb) {
		trace_xdp_exception(dev, xdp_prog, XDP_TX);
		kfree_skb(skb);
	}
}

The product dereferences a pointer that it expects to be valid but is NULL.