So I found the root cause here : we had icmp rules in a machine secgroup. icmp rules typically don't have ports associated (they show as "-1" in nova secgroup-list-rule). Once I removed said icmp rules, the panics stopped.
So I found the root cause here : we had icmp rules in a machine secgroup. icmp rules typically don't have ports associated (they show as "-1" in nova secgroup- list-rule) . Once I removed said icmp rules, the panics stopped.