From: Florian Westphal <fw@strlen.de>
Date: Thu, 27 Jun 2019 14:03:31 +0200

Tariq and Ran reported a regression caused by net-next commit
2638eb8b50cf ("net: ipv4: provide __rcu annotation for ifa_list").

This happens when net.ipv4.conf.$dev.promote_secondaries sysctl is
enabled -- we can arrange for ifa->next to point at ifa, so next
process that tries to walk the list loops forever.

Fix this and extend rtnetlink.sh with a small test case for this.

Series applied, thanks Florian.