Merge tag 'nf-25-12-10' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf

Florian Westphal says:

====================
netfilter: updates for net

1) Fix refcount leaks in nf_conncount, from Fernando Fernandez Mancera.
   This addresses a recent regression that came in the last -next
   pull request.

2) Fix a null dereference in route error handling in IPVS, from Slavin
   Liu.  This is an ancient issue dating back to 5.1 days.

3) Always set ifindex in route tuple in the flowtable output path, from
   Lorenzo Bianconi.  This bug came in with the recent output path refactoring.

4) Prefer 'exit $ksft_xfail' over 'exit $ksft_skip' when we fail to
   trigger a nat race condition to exercise the clash resolution path in
   selftest infra, $ksft_skip should be reserved for missing tooling,
   From myself.

* tag 'nf-25-12-10' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  selftests: netfilter: prefer xfail in case race wasn't triggered
  netfilter: always set route tuple out ifindex
  ipvs: fix ipv4 null-ptr-deref in route error path
  netfilter: nf_conncount: fix leaked ct in error paths
====================

Link: https://patch.msgid.link/20251210110754.22620-1-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

4 files changed, 24 insertions, 17 deletions

diff --git a/net/netfilter/ipvs/ip_vs_xmit.c b/net/netfilter/ipvs/ip_vs_xmit.c
index 3162ce3c2640..64c697212578 100644
--- a/net/netfilter/ipvs/ip_vs_xmit.c
+++ b/net/netfilter/ipvs/ip_vs_xmit.c
@@ -408,6 +408,9 @@ err_put:
 	return -1;
 
 err_unreach:
+	if (!skb->dev)
+		skb->dev = skb_dst(skb)->dev;
+
 	dst_link_failure(skb);
 	return -1;
 }
diff --git a/net/netfilter/nf_conncount.c b/net/netfilter/nf_conncount.c
index f1be4dd5cf85..3654f1e8976c 100644
--- a/net/netfilter/nf_conncount.c
+++ b/net/netfilter/nf_conncount.c
@@ -172,14 +172,14 @@ static int __nf_conncount_add(struct net *net,
 	struct nf_conn *found_ct;
 	unsigned int collect = 0;
 	bool refcounted = false;
+	int err = 0;
 
 	if (!get_ct_or_tuple_from_skb(net, skb, l3num, &ct, &tuple, &zone, &refcounted))
 		return -ENOENT;
 
 	if (ct && nf_ct_is_confirmed(ct)) {
-		if (refcounted)
-			nf_ct_put(ct);
-		return -EEXIST;
+		err = -EEXIST;
+		goto out_put;
 	}
 
 	if ((u32)jiffies == list->last_gc)
@@ -231,12 +231,16 @@ static int __nf_conncount_add(struct net *net,
 	}
 
 add_new_node:
-	if (WARN_ON_ONCE(list->count > INT_MAX))
-		return -EOVERFLOW;
+	if (WARN_ON_ONCE(list->count > INT_MAX)) {
+		err = -EOVERFLOW;
+		goto out_put;
+	}
 
 	conn = kmem_cache_alloc(conncount_conn_cachep, GFP_ATOMIC);
-	if (conn == NULL)
-		return -ENOMEM;
+	if (conn == NULL) {
+		err = -ENOMEM;
+		goto out_put;
+	}
 
 	conn->tuple = tuple;
 	conn->zone = *zone;
@@ -249,7 +253,7 @@ add_new_node:
 out_put:
 	if (refcounted)
 		nf_ct_put(ct);
-	return 0;
+	return err;
 }
 
 int nf_conncount_add_skb(struct net *net,
@@ -456,11 +460,10 @@ restart:
 
 		rb_link_node_rcu(&rbconn->node, parent, rbnode);
 		rb_insert_color(&rbconn->node, root);
-
-		if (refcounted)
-			nf_ct_put(ct);
 	}
 out_unlock:
+	if (refcounted)
+		nf_ct_put(ct);
 	spin_unlock_bh(&nf_conncount_locks[hash]);
 	return count;
 }
diff --git a/net/netfilter/nf_flow_table_path.c b/net/netfilter/nf_flow_table_path.c
index f0984cf69a09..eb24fe2715dc 100644
--- a/net/netfilter/nf_flow_table_path.c
+++ b/net/netfilter/nf_flow_table_path.c
@@ -250,6 +250,9 @@ static void nft_dev_forward_path(const struct nft_pktinfo *pkt,
 	if (nft_dev_fill_forward_path(route, dst, ct, dir, ha, &stack) >= 0)
 		nft_dev_path_info(&stack, &info, ha, &ft->data);
 
+	if (info.outdev)
+		route->tuple[dir].out.ifindex = info.outdev->ifindex;
+
 	if (!info.indev || !nft_flowtable_find_dev(info.indev, ft))
 		return;
 
@@ -269,7 +272,6 @@ static void nft_dev_forward_path(const struct nft_pktinfo *pkt,
 
 	route->tuple[!dir].in.num_encaps = info.num_encaps;
 	route->tuple[!dir].in.ingress_vlans = info.ingress_vlans;
-	route->tuple[dir].out.ifindex = info.outdev->ifindex;
 
 	if (info.xmit_type == FLOW_OFFLOAD_XMIT_DIRECT) {
 		memcpy(route->tuple[dir].out.h_source, info.h_source, ETH_ALEN);
diff --git a/tools/testing/selftests/net/netfilter/conntrack_clash.sh b/tools/testing/selftests/net/netfilter/conntrack_clash.sh
index 7fc6c5dbd551..84b8eb12143a 100755
--- a/tools/testing/selftests/net/netfilter/conntrack_clash.sh
+++ b/tools/testing/selftests/net/netfilter/conntrack_clash.sh
@@ -116,7 +116,7 @@ run_one_clash_test()
 	# not a failure: clash resolution logic did not trigger.
 	# With right timing, xmit completed sequentially and
 	# no parallel insertion occurs.
-	return $ksft_skip
+	return $ksft_xfail
 }
 
 run_clash_test()
@@ -133,12 +133,12 @@ run_clash_test()
 		if [ $rv -eq 0 ];then
 			echo "PASS: clash resolution test for $daddr:$dport on attempt $i"
 			return 0
-		elif [ $rv -eq $ksft_skip ]; then
+		elif [ $rv -eq $ksft_xfail ]; then
 			softerr=1
 		fi
 	done
 
-	[ $softerr -eq 1 ] && echo "SKIP: clash resolution for $daddr:$dport did not trigger"
+	[ $softerr -eq 1 ] && echo "XFAIL: clash resolution for $daddr:$dport did not trigger"
 }
 
 ip link add veth0 netns "$nsclient1" type veth peer name veth0 netns "$nsrouter"
@@ -167,8 +167,7 @@ load_simple_ruleset "$nsclient2"
 run_clash_test "$nsclient2" "$nsclient2" 127.0.0.1 9001
 
 if [ $clash_resolution_active -eq 0 ];then
-	[ "$ret" -eq 0 ] && ret=$ksft_skip
-	echo "SKIP: Clash resolution did not trigger"
+	[ "$ret" -eq 0 ] && ret=$ksft_xfail
 fi
 
 exit $ret