Merge branch 'ipv6-fixes'

Hangbin Liu says:

====================
fix two kernel panics when disabled IPv6 on boot up

When disabled IPv6 on boot up, since there is no ipv6 route tables, we should
not call rt6_lookup. Fix them by checking if we have inet6_dev pointer on
netdevice.

v2: Fix idev reference leak, declarations and code mixing as Stefano,
    Eric pointed. Since we only want to check if idev exists and not
    reference it, use __in6_dev_get() insteand of in6_dev_get().
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/geneve.c

@@ -1512,9 +1512,13 @@ static void geneve_link_config(struct net_device *dev,
 	}
 #if IS_ENABLED(CONFIG_IPV6)
 	case AF_INET6: {
-		struct rt6_info *rt = rt6_lookup(geneve->net,
-						 &info->key.u.ipv6.dst, NULL, 0,
-						 NULL, 0);
+		struct rt6_info *rt;
+
+		if (!__in6_dev_get(dev))
+			break;
+
+		rt = rt6_lookup(geneve->net, &info->key.u.ipv6.dst, NULL, 0,
+				NULL, 0);
 
 		if (rt && rt->dst.dev)
 			ldev_mtu = rt->dst.dev->mtu - GENEVE_IPV6_HLEN;

net/ipv6/sit.c

@@ -546,7 +546,8 @@ static int ipip6_err(struct sk_buff *skb, u32 info)
 	}
 
 	err = 0;
-	if (!ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len))
+	if (__in6_dev_get(skb->dev) &&
+	    !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len))
 		goto out;
 
 	if (t->parms.iph.daddr == 0)