static int vfio_pci_for_each_slot_or_bus(struct pci_dev *pdev,
					 int (*fn)(struct pci_dev *,
						   void *data), void *data,
					 bool slot)
{
	struct vfio_pci_walk_info walk = {
		.fn = fn, .data = data, .pdev = pdev, .slot = slot, .ret = 0,
	};

	pci_walk_bus(pdev->bus, vfio_pci_walk_wrapper, &walk);

	return walk.ret;
}

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.