diff -drupN a/net/ipv4/route.c b/net/ipv4/route.c
--- a/net/ipv4/route.c	2018-08-06 17:23:04.000000000 +0300
+++ b/net/ipv4/route.c	2022-06-12 05:28:14.000000000 +0300
@@ -510,7 +510,8 @@ void __ip_select_ident(struct net *net,
 }
 EXPORT_SYMBOL(__ip_select_ident);
 
-static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
+static void __build_flow_key(const struct net *net, struct flowi4 *fl4,
+			     const struct sock *sk,
 			     const struct iphdr *iph,
 			     int oif, u8 tos,
 			     u8 prot, u32 mark, int flow_flags)
@@ -526,19 +527,21 @@ static void __build_flow_key(struct flow
 	flowi4_init_output(fl4, oif, mark, tos,
 			   RT_SCOPE_UNIVERSE, prot,
 			   flow_flags,
-			   iph->daddr, iph->saddr, 0, 0);
+			   iph->daddr, iph->saddr, 0, 0,
+			   sock_net_uid(net, sk));
 }
 
 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
 			       const struct sock *sk)
 {
+	const struct net *net = dev_net(skb->dev);
 	const struct iphdr *iph = ip_hdr(skb);
 	int oif = skb->dev->ifindex;
 	u8 tos = RT_TOS(iph->tos);
 	u8 prot = iph->protocol;
 	u32 mark = skb->mark;
 
-	__build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
+	__build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0);
 }
 
 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
@@ -555,7 +558,7 @@ static void build_sk_flow_key(struct flo
 			   RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
 			   inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
 			   inet_sk_flowi_flags(sk),
-			   daddr, inet->inet_saddr, 0, 0);
+			   daddr, inet->inet_saddr, 0, 0, sk->sk_uid);
 	rcu_read_unlock();
 }
 
@@ -807,6 +810,7 @@ static void ip_do_redirect(struct dst_en
 	struct rtable *rt;
 	struct flowi4 fl4;
 	const struct iphdr *iph = (const struct iphdr *) skb->data;
+	struct net *net = dev_net(skb->dev);
 	int oif = skb->dev->ifindex;
 	u8 tos = RT_TOS(iph->tos);
 	u8 prot = iph->protocol;
@@ -814,7 +818,7 @@ static void ip_do_redirect(struct dst_en
 
 	rt = (struct rtable *) dst;
 
-	__build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0);
+	__build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0);
 	__ip_do_redirect(rt, skb, &fl4, true);
 }
 
@@ -1035,7 +1039,7 @@ void ipv4_update_pmtu(struct sk_buff *sk
 	if (!mark)
 		mark = IP4_REPLY_MARK(net, skb->mark);
 
-	__build_flow_key(&fl4, NULL, iph, oif,
+	__build_flow_key(net, &fl4, NULL, iph, oif,
 			 RT_TOS(iph->tos), protocol, mark, flow_flags);
 	rt = __ip_route_output_key(net, &fl4);
 	if (!IS_ERR(rt)) {
@@ -1051,7 +1055,7 @@ static void __ipv4_sk_update_pmtu(struct
 	struct flowi4 fl4;
 	struct rtable *rt;
 
-	__build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
+	__build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0);
 
 	if (!fl4.flowi4_mark)
 		fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
@@ -1070,6 +1074,7 @@ void ipv4_sk_update_pmtu(struct sk_buff
 	struct rtable *rt;
 	struct dst_entry *odst = NULL;
 	bool new = false;
+	struct net *net = sock_net(sk);
 
 	bh_lock_sock(sk);
 
@@ -1083,7 +1088,7 @@ void ipv4_sk_update_pmtu(struct sk_buff
 		goto out;
 	}
 
-	__build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
+	__build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0);
 
 	rt = (struct rtable *)odst;
 	if (odst->obsolete && !odst->ops->check(odst, 0)) {
@@ -1123,7 +1128,7 @@ void ipv4_redirect(struct sk_buff *skb,
 	struct flowi4 fl4;
 	struct rtable *rt;
 
-	__build_flow_key(&fl4, NULL, iph, oif,
+	__build_flow_key(net, &fl4, NULL, iph, oif,
 			 RT_TOS(iph->tos), protocol, mark, flow_flags);
 	rt = __ip_route_output_key(net, &fl4);
 	if (!IS_ERR(rt)) {
@@ -1138,9 +1143,10 @@ void ipv4_sk_redirect(struct sk_buff *sk
 	const struct iphdr *iph = (const struct iphdr *) skb->data;
 	struct flowi4 fl4;
 	struct rtable *rt;
+	struct net *net = sock_net(sk);
 
-	__build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
-	rt = __ip_route_output_key(sock_net(sk), &fl4);
+	__build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0);
+	rt = __ip_route_output_key(net, &fl4);
 	if (!IS_ERR(rt)) {
 		__ip_do_redirect(rt, skb, &fl4, false);
 		ip_rt_put(rt);
@@ -2524,6 +2530,11 @@ static int rt_fill_info(struct net *net,
 	    nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
 		goto nla_put_failure;
 
+	if (!uid_eq(fl4->flowi4_uid, INVALID_UID) &&
+	    nla_put_u32(skb, RTA_UID,
+			from_kuid_munged(current_user_ns(), fl4->flowi4_uid)))
+		goto nla_put_failure;
+
 	error = rt->dst.error;
 
 	if (rt_is_input_route(rt)) {
@@ -2576,6 +2587,7 @@ static int inet_rtm_getroute(struct sk_b
 	int mark;
 	struct sk_buff *skb;
 	u32 table_id = RT_TABLE_MAIN;
+	kuid_t uid;
 
 	err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
 	if (err < 0)
@@ -2603,6 +2615,10 @@ static int inet_rtm_getroute(struct sk_b
 	dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
 	iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
 	mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
+	if (tb[RTA_UID])
+		uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID]));
+	else
+		uid = (iif ? INVALID_UID : current_uid());
 
 	memset(&fl4, 0, sizeof(fl4));
 	fl4.daddr = dst;
@@ -2610,6 +2626,7 @@ static int inet_rtm_getroute(struct sk_b
 	fl4.flowi4_tos = rtm->rtm_tos;
 	fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
 	fl4.flowi4_mark = mark;
+	fl4.flowi4_uid = uid;
 
 	if (iif) {
 		struct net_device *dev;