Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[linux.git] / net / ipv6 / addrconf.c

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 6a576ff92c399fbb686c839c525e700f2579b1a9..34ccef18b40e60e283a63c18102fef8b927cbfaf 100644 (file)
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -5964,13 +5964,20 @@ static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp)
        switch (event) {
        case RTM_NEWADDR:
                /*
-                * If the address was optimistic
-                * we inserted the route at the start of
-                * our DAD process, so we don't need
-                * to do it again
+                * If the address was optimistic we inserted the route at the
+                * start of our DAD process, so we don't need to do it again.
+                * If the device was taken down in the middle of the DAD
+                * cycle there is a race where we could get here without a
+                * host route, so nothing to insert. That will be fixed when
+                * the device is brought up.
                 */
-               if (!rcu_access_pointer(ifp->rt->fib6_node))
+               if (ifp->rt && !rcu_access_pointer(ifp->rt->fib6_node)) {
                        ip6_ins_rt(net, ifp->rt);
+               } else if (!ifp->rt && (ifp->idev->dev->flags & IFF_UP)) {
+                       pr_warn("BUG: Address %pI6c on device %s is missing its host route.\n",
+                               &ifp->addr, ifp->idev->dev->name);
+               }
+
                if (ifp->idev->cnf.forwarding)
                        addrconf_join_anycast(ifp);
                if (!ipv6_addr_any(&ifp->peer_addr))