In the Linux kernel, the following vulnerability has been resolved:

ipv4: prevent potential spectre v1 gadget in ip_metrics_convert()

if (!type)
		continue;
	if (type > RTAX_MAX)
		return -EINVAL;
	...
	metrics[type - 1] = val;

@type being used as an array index, we need to prevent
cpu speculation or risk leaking kernel memory content.