static void __init vfio_pci_fill_ids(void)
{
	char *p, *id;
	int rc;

	/* no ids passed actually */
	if (ids[0] == '\0')
		return;

	/* add ids specified in the module parameter */
	p = ids;
	while ((id = strsep(&p, ","))) {
		unsigned int vendor, device, subvendor = PCI_ANY_ID,
			subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
		int fields;

		if (!strlen(id))
			continue;

		fields = sscanf(id, "%x:%x:%x:%x:%x:%x",
				&vendor, &device, &subvendor, &subdevice,
				&class, &class_mask);

		if (fields < 2) {
			pr_warn("invalid id string \"%s\"\n", id);
			continue;
		}

		rc = pci_add_dynid(&vfio_pci_driver, vendor, device,
				   subvendor, subdevice, class, class_mask, 0);
		if (rc)
			pr_warn("failed to add dynamic id [%04hx:%04hx[%04hx:%04hx]] class %#08x/%08x (%d)\n",
				vendor, device, subvendor, subdevice,
				class, class_mask, rc);
		else
			pr_info("add [%04hx:%04hx[%04hx:%04hx]] class %#08x/%08x\n",
				vendor, device, subvendor, subdevice,
				class, class_mask);
	}
}

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.