In the Linux kernel, the following vulnerability has been resolved: ipv6: prevent infinite loop in rt6nlmsgsize() While testing prior patch, I was able to trigger an infinite loop in rt6nlmsgsize() in the following place: listforeachentryrcu(sibling, &f6i->fib6siblings, fib6siblings) { rt6nhnlmsgsize(sibling->fib6nh, &nexthoplen); } This is because fib6delroute() and fib6addrt2node() uses listdelrcu(), which can confuse rcu readers, because they might no longer see the head of the list. Restart the loop if f6i->fib6nsiblings is zero.