static int pppoe_seq_show(struct seq_file *seq, void *v)
{
	struct pppox_sock *po;
	char *dev_name;

	if (v == SEQ_START_TOKEN) {
		seq_puts(seq, "Id       Address              Device\n");
		goto out;
	}

	po = v;
	dev_name = po->pppoe_pa.dev;

	seq_printf(seq, "%08X %pM %8s\n",
		po->pppoe_pa.sid, po->pppoe_pa.remote, dev_name);
out:
	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.