int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
{
	int ret = ____dev_forward_skb(dev, skb);

	if (likely(!ret)) {
		skb->protocol = eth_type_trans(skb, dev);
		skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
	}

	return ret;
}

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