1 files changed, 21 insertions, 15 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index b6a6f18c3dd1..7dcce724c78b 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -635,6 +635,7 @@ static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnh
 
         if (fnhe->fnhe_gw) {
                 rt->rt_flags |= RTCF_REDIRECTED;
+                rt->rt_uses_gateway = 1;
                 rt->rt_gw_family = AF_INET;
                 rt->rt_gw4 = fnhe->fnhe_gw;
         }
@@ -1313,7 +1314,7 @@ static unsigned int ipv4_mtu(const struct dst_entry *dst)
         mtu = READ_ONCE(dst->dev->mtu);
 
         if (unlikely(ip_mtu_locked(dst))) {
-                if (rt->rt_gw_family && mtu > 576)
+                if (rt->rt_uses_gateway && mtu > 576)
                         mtu = 576;
         }
 
@@ -1569,6 +1570,7 @@ static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
                 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
 
                 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) {
+                        rt->rt_uses_gateway = 1;
                         rt->rt_gw_family = nhc->nhc_gw_family;
                         /* only INET and INET6 are supported */
                         if (likely(nhc->nhc_gw_family == AF_INET))
@@ -1634,6 +1636,7 @@ struct rtable *rt_dst_alloc(struct net_device *dev,
                 rt->rt_iif = 0;
                 rt->rt_pmtu = 0;
                 rt->rt_mtu_locked = 0;
+                rt->rt_uses_gateway = 0;
                 rt->rt_gw_family = 0;
                 rt->rt_gw4 = 0;
                 INIT_LIST_HEAD(&rt->rt_uncached);
@@ -2694,6 +2697,7 @@ struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_or
                 rt->rt_genid = rt_genid_ipv4(net);
                 rt->rt_flags = ort->rt_flags;
                 rt->rt_type = ort->rt_type;
+                rt->rt_uses_gateway = ort->rt_uses_gateway;
                 rt->rt_gw_family = ort->rt_gw_family;
                 if (rt->rt_gw_family == AF_INET)
                         rt->rt_gw4 = ort->rt_gw4;
@@ -2778,21 +2782,23 @@ static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
                 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr))
                         goto nla_put_failure;
         }
-        if (rt->rt_gw_family == AF_INET &&
-            nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) {
-                goto nla_put_failure;
-        } else if (rt->rt_gw_family == AF_INET6) {
-                int alen = sizeof(struct in6_addr);
-                struct nlattr *nla;
-                struct rtvia *via;
-
-                nla = nla_reserve(skb, RTA_VIA, alen + 2);
-                if (!nla)
+        if (rt->rt_uses_gateway) {
+                if (rt->rt_gw_family == AF_INET &&
+                    nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) {
                         goto nla_put_failure;
-
-                via = nla_data(nla);
-                via->rtvia_family = AF_INET6;
-                memcpy(via->rtvia_addr, &rt->rt_gw6, alen);
+                } else if (rt->rt_gw_family == AF_INET6) {
+                        int alen = sizeof(struct in6_addr);
+                        struct nlattr *nla;
+                        struct rtvia *via;
+
+                        nla = nla_reserve(skb, RTA_VIA, alen + 2);
+                        if (!nla)
+                                goto nla_put_failure;
+
+                        via = nla_data(nla);
+                        via->rtvia_family = AF_INET6;
+                        memcpy(via->rtvia_addr, &rt->rt_gw6, alen);
+                }
         }
 
         expires = rt->dst.expires;