2 files changed, 8 insertions, 1 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index db1e0da871f4..50e1e0feddfc 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -993,6 +993,9 @@ void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
         struct flowi4 fl4;
         struct rtable *rt;
 
+        if (!mark)
+                mark = IP4_REPLY_MARK(net, skb->mark);
+
         __build_flow_key(&fl4, NULL, iph, oif,
                          RT_TOS(iph->tos), protocol, mark, flow_flags);
         rt = __ip_route_output_key(net, &fl4);
@@ -1010,6 +1013,10 @@ static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
         struct rtable *rt;
 
         __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
+
+        if (!fl4.flowi4_mark)
+                fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
+
         rt = __ip_route_output_key(sock_net(sk), &fl4);
         if (!IS_ERR(rt)) {
                 __ip_rt_update_pmtu(rt, &fl4, mtu);
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 004fffb6c221..f0a8ff9ed891 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1176,7 +1176,7 @@ void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu,
 
         memset(&fl6, 0, sizeof(fl6));
         fl6.flowi6_oif = oif;
-        fl6.flowi6_mark = mark;
+        fl6.flowi6_mark = mark ? mark : IP6_REPLY_MARK(net, skb->mark);
         fl6.daddr = iph->daddr;
         fl6.saddr = iph->saddr;
         fl6.flowlabel = ip6_flowinfo(iph);