1 files changed, 23 insertions, 8 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 0383e66f59bc..94d4cd2d5ea4 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1267,7 +1267,7 @@ static unsigned int ipv4_mtu(const struct dst_entry *dst)
 	if (mtu)
 		return mtu;
 
-	mtu = dst->dev->mtu;
+	mtu = READ_ONCE(dst->dev->mtu);
 
 	if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
 		if (rt->rt_uses_gateway && mtu > 576)
@@ -1398,7 +1398,7 @@ static void ipv4_dst_destroy(struct dst_entry *dst)
 	struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst);
 	struct rtable *rt = (struct rtable *) dst;
 
-	if (p != &dst_default_metrics && atomic_dec_and_test(&p->refcnt))
+	if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt))
 		kfree(p);
 
 	if (!list_empty(&rt->rt_uncached)) {
@@ -1456,7 +1456,7 @@ static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
 		dst_init_metrics(&rt->dst, fi->fib_metrics->metrics, true);
 		if (fi->fib_metrics != &dst_default_metrics) {
 			rt->dst._metrics |= DST_METRICS_REFCOUNTED;
-			atomic_inc(&fi->fib_metrics->refcnt);
+			refcount_inc(&fi->fib_metrics->refcnt);
 		}
 #ifdef CONFIG_IP_ROUTE_CLASSID
 		rt->dst.tclassid = nh->nh_tclassid;
@@ -2236,7 +2236,7 @@ add:
 	if (!rth)
 		return ERR_PTR(-ENOBUFS);
 
-	rth->rt_iif	= orig_oif ? : 0;
+	rth->rt_iif = orig_oif;
 	if (res->table)
 		rth->rt_table_id = res->table->tb_id;
 
@@ -2439,6 +2439,12 @@ struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4,
 		/* L3 master device is the loopback for that domain */
 		dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? :
 			net->loopback_dev;
+
+		/* make sure orig_oif points to fib result device even
+		 * though packet rx/tx happens over loopback or l3mdev
+		 */
+		orig_oif = FIB_RES_OIF(*res);
+
 		fl4->flowi4_oif = dev_out->ifindex;
 		flags |= RTCF_LOCAL;
 		goto make_route;
@@ -2750,26 +2756,34 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
 		err = 0;
 		if (IS_ERR(rt))
 			err = PTR_ERR(rt);
+		else
+			skb_dst_set(skb, &rt->dst);
 	}
 
 	if (err)
 		goto errout_free;
 
-	skb_dst_set(skb, &rt->dst);
 	if (rtm->rtm_flags & RTM_F_NOTIFY)
 		rt->rt_flags |= RTCF_NOTIFY;
 
 	if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE)
 		table_id = rt->rt_table_id;
 
-	if (rtm->rtm_flags & RTM_F_FIB_MATCH)
+	if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
+		if (!res.fi) {
+			err = fib_props[res.type].error;
+			if (!err)
+				err = -EHOSTUNREACH;
+			goto errout_free;
+		}
 		err = fib_dump_info(skb, NETLINK_CB(in_skb).portid,
 				    nlh->nlmsg_seq, RTM_NEWROUTE, table_id,
 				    rt->rt_type, res.prefix, res.prefixlen,
 				    fl4.flowi4_tos, res.fi, 0);
-	else
+	} else {
 		err = rt_fill_info(net, dst, src, table_id, &fl4, skb,
 				   NETLINK_CB(in_skb).portid, nlh->nlmsg_seq);
+	}
 	if (err < 0)
 		goto errout_free;
 
@@ -3067,7 +3081,8 @@ int __init ip_rt_init(void)
 	xfrm_init();
 	xfrm4_init();
 #endif
-	rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
+	rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL,
+		      RTNL_FLAG_DOIT_UNLOCKED);
 
 #ifdef CONFIG_SYSCTL
 	register_pernet_subsys(&sysctl_route_ops);