Merge tag 'nf-25-08-07' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

1) Reinstantiate Florian Westphal as a Netfilter maintainer.

2) Depend on both NETFILTER_XTABLES and NETFILTER_XTABLES_LEGACY,
   from Arnd Bergmann.

3) Use id to annotate last conntrack/expectation visited to resume
   netlink dump, patches from Florian Westphal.

4) Fix bogus element in nft_pipapo avx2 lookup, introduced in
   the last nf-next batch of updates, also from Florian.

5) Return 0 instead of recycling ret variable in
   nf_conntrack_log_invalid_sysctl(), introduced in the last
   nf-next batch of updates, from Dan Carpenter.

6) Fix WARN_ON_ONCE triggered by syzbot with larger cgroup level
   in nft_socket.

* tag 'nf-25-08-07' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nft_socket: remove WARN_ON_ONCE with huge level value
  netfilter: conntrack: clean up returns in nf_conntrack_log_invalid_sysctl()
  netfilter: nft_set_pipapo: don't return bogus extension pointer
  netfilter: ctnetlink: remove refcounting in expectation dumpers
  netfilter: ctnetlink: fix refcount leak on table dump
  netfilter: add back NETFILTER_XTABLES dependencies
  MAINTAINERS: resurrect my netfilter maintainer entry
====================

Link: https://patch.msgid.link/20250807112948.1400523-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

8 files changed, 46 insertions, 45 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index bd62ad58a47f..eed16e53b9b2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -17451,6 +17451,7 @@ F:	drivers/net/ethernet/neterion/
 NETFILTER
 M:	Pablo Neira Ayuso <pablo@netfilter.org>
 M:	Jozsef Kadlecsik <kadlec@netfilter.org>
+M:	Florian Westphal <fw@strlen.de>
 L:	netfilter-devel@vger.kernel.org
 L:	coreteam@netfilter.org
 S:	Maintained
diff --git a/net/bridge/netfilter/Kconfig b/net/bridge/netfilter/Kconfig
index 60f28e4fb5c0..4fd5a6ea26b4 100644
--- a/net/bridge/netfilter/Kconfig
+++ b/net/bridge/netfilter/Kconfig
@@ -43,6 +43,7 @@ config NF_CONNTRACK_BRIDGE
 config BRIDGE_NF_EBTABLES_LEGACY
 	tristate "Legacy EBTABLES support"
 	depends on BRIDGE && NETFILTER_XTABLES_LEGACY
+	depends on NETFILTER_XTABLES
 	default	n
 	help
 	 Legacy ebtables packet/frame classifier.
diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index 2c438b140e88..7dc9772fe2d8 100644
--- a/net/ipv4/netfilter/Kconfig
+++ b/net/ipv4/netfilter/Kconfig
@@ -14,6 +14,7 @@ config NF_DEFRAG_IPV4
 config IP_NF_IPTABLES_LEGACY
 	tristate "Legacy IP tables support"
 	depends on NETFILTER_XTABLES_LEGACY
+	depends on NETFILTER_XTABLES
 	default	m if NETFILTER_XTABLES_LEGACY
 	help
 	  iptables is a legacy packet classifier.
@@ -326,6 +327,7 @@ endif # IP_NF_IPTABLES
 config IP_NF_ARPTABLES
 	tristate "Legacy ARPTABLES support"
 	depends on NETFILTER_XTABLES_LEGACY
+	depends on NETFILTER_XTABLES
 	default	n
 	help
 	  arptables is a legacy packet classifier.
@@ -343,6 +345,7 @@ config IP_NF_ARPFILTER
 	select IP_NF_ARPTABLES
 	select NETFILTER_FAMILY_ARP
 	depends on NETFILTER_XTABLES_LEGACY
+	depends on NETFILTER_XTABLES
 	help
 	  ARP packet filtering defines a table `filter', which has a series of
 	  rules for simple ARP packet filtering at local input and
diff --git a/net/ipv6/netfilter/Kconfig b/net/ipv6/netfilter/Kconfig
index 276860f65baa..81daf82ddc2d 100644
--- a/net/ipv6/netfilter/Kconfig
+++ b/net/ipv6/netfilter/Kconfig
@@ -10,6 +10,7 @@ menu "IPv6: Netfilter Configuration"
 config IP6_NF_IPTABLES_LEGACY
 	tristate "Legacy IP6 tables support"
 	depends on INET && IPV6 && NETFILTER_XTABLES_LEGACY
+	depends on NETFILTER_XTABLES
 	default	m if NETFILTER_XTABLES_LEGACY
 	help
 	  ip6tables is a legacy packet classifier.
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 486d52b45fe5..50fd6809380f 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -884,8 +884,6 @@ errout:
 
 static int ctnetlink_done(struct netlink_callback *cb)
 {
-	if (cb->args[1])
-		nf_ct_put((struct nf_conn *)cb->args[1]);
 	kfree(cb->data);
 	return 0;
 }
@@ -1208,19 +1206,26 @@ ignore_entry:
 	return 0;
 }
 
+static unsigned long ctnetlink_get_id(const struct nf_conn *ct)
+{
+	unsigned long id = nf_ct_get_id(ct);
+
+	return id ? id : 1;
+}
+
 static int
 ctnetlink_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	unsigned int flags = cb->data ? NLM_F_DUMP_FILTERED : 0;
 	struct net *net = sock_net(skb->sk);
-	struct nf_conn *ct, *last;
+	unsigned long last_id = cb->args[1];
 	struct nf_conntrack_tuple_hash *h;
 	struct hlist_nulls_node *n;
 	struct nf_conn *nf_ct_evict[8];
+	struct nf_conn *ct;
 	int res, i;
 	spinlock_t *lockp;
 
-	last = (struct nf_conn *)cb->args[1];
 	i = 0;
 
 	local_bh_disable();
@@ -1257,7 +1262,7 @@ restart:
 				continue;
 
 			if (cb->args[1]) {
-				if (ct != last)
+				if (ctnetlink_get_id(ct) != last_id)
 					continue;
 				cb->args[1] = 0;
 			}
@@ -1270,8 +1275,7 @@ restart:
 					    NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
 					    ct, true, flags);
 			if (res < 0) {
-				nf_conntrack_get(&ct->ct_general);
-				cb->args[1] = (unsigned long)ct;
+				cb->args[1] = ctnetlink_get_id(ct);
 				spin_unlock(lockp);
 				goto out;
 			}
@@ -1284,12 +1288,10 @@ restart:
 	}
 out:
 	local_bh_enable();
-	if (last) {
+	if (last_id) {
 		/* nf ct hash resize happened, now clear the leftover. */
-		if ((struct nf_conn *)cb->args[1] == last)
+		if (cb->args[1] == last_id)
 			cb->args[1] = 0;
-
-		nf_ct_put(last);
 	}
 
 	while (i) {
@@ -3168,23 +3170,27 @@ errout:
 	return 0;
 }
 #endif
-static int ctnetlink_exp_done(struct netlink_callback *cb)
+
+static unsigned long ctnetlink_exp_id(const struct nf_conntrack_expect *exp)
 {
-	if (cb->args[1])
-		nf_ct_expect_put((struct nf_conntrack_expect *)cb->args[1]);
-	return 0;
+	unsigned long id = (unsigned long)exp;
+
+	id += nf_ct_get_id(exp->master);
+	id += exp->class;
+
+	return id ? id : 1;
 }
 
 static int
 ctnetlink_exp_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	struct net *net = sock_net(skb->sk);
-	struct nf_conntrack_expect *exp, *last;
 	struct nfgenmsg *nfmsg = nlmsg_data(cb->nlh);
 	u_int8_t l3proto = nfmsg->nfgen_family;
+	unsigned long last_id = cb->args[1];
+	struct nf_conntrack_expect *exp;
 
 	rcu_read_lock();
-	last = (struct nf_conntrack_expect *)cb->args[1];
 	for (; cb->args[0] < nf_ct_expect_hsize; cb->args[0]++) {
 restart:
 		hlist_for_each_entry_rcu(exp, &nf_ct_expect_hash[cb->args[0]],
@@ -3196,7 +3202,7 @@ restart:
 				continue;
 
 			if (cb->args[1]) {
-				if (exp != last)
+				if (ctnetlink_exp_id(exp) != last_id)
 					continue;
 				cb->args[1] = 0;
 			}
@@ -3205,9 +3211,7 @@ restart:
 						    cb->nlh->nlmsg_seq,
 						    IPCTNL_MSG_EXP_NEW,
 						    exp) < 0) {
-				if (!refcount_inc_not_zero(&exp->use))
-					continue;
-				cb->args[1] = (unsigned long)exp;
+				cb->args[1] = ctnetlink_exp_id(exp);
 				goto out;
 			}
 		}
@@ -3218,32 +3222,30 @@ restart:
 	}
 out:
 	rcu_read_unlock();
-	if (last)
-		nf_ct_expect_put(last);
-
 	return skb->len;
 }
 
 static int
 ctnetlink_exp_ct_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
 {
-	struct nf_conntrack_expect *exp, *last;
 	struct nfgenmsg *nfmsg = nlmsg_data(cb->nlh);
 	struct nf_conn *ct = cb->data;
 	struct nf_conn_help *help = nfct_help(ct);
 	u_int8_t l3proto = nfmsg->nfgen_family;
+	unsigned long last_id = cb->args[1];
+	struct nf_conntrack_expect *exp;
 
 	if (cb->args[0])
 		return 0;
 
 	rcu_read_lock();
-	last = (struct nf_conntrack_expect *)cb->args[1];
+
 restart:
 	hlist_for_each_entry_rcu(exp, &help->expectations, lnode) {
 		if (l3proto && exp->tuple.src.l3num != l3proto)
 			continue;
 		if (cb->args[1]) {
-			if (exp != last)
+			if (ctnetlink_exp_id(exp) != last_id)
 				continue;
 			cb->args[1] = 0;
 		}
@@ -3251,9 +3253,7 @@ restart:
 					    cb->nlh->nlmsg_seq,
 					    IPCTNL_MSG_EXP_NEW,
 					    exp) < 0) {
-			if (!refcount_inc_not_zero(&exp->use))
-				continue;
-			cb->args[1] = (unsigned long)exp;
+			cb->args[1] = ctnetlink_exp_id(exp);
 			goto out;
 		}
 	}
@@ -3264,9 +3264,6 @@ restart:
 	cb->args[0] = 1;
 out:
 	rcu_read_unlock();
-	if (last)
-		nf_ct_expect_put(last);
-
 	return skb->len;
 }
 
@@ -3285,7 +3282,6 @@ static int ctnetlink_dump_exp_ct(struct net *net, struct sock *ctnl,
 	struct nf_conntrack_zone zone;
 	struct netlink_dump_control c = {
 		.dump = ctnetlink_exp_ct_dump_table,
-		.done = ctnetlink_exp_done,
 	};
 
 	err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_MASTER,
@@ -3335,7 +3331,6 @@ static int ctnetlink_get_expect(struct sk_buff *skb,
 		else {
 			struct netlink_dump_control c = {
 				.dump = ctnetlink_exp_dump_table,
-				.done = ctnetlink_exp_done,
 			};
 			return netlink_dump_start(info->sk, skb, info->nlh, &c);
 		}
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index 9b8b10a85233..1f14ef0436c6 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -567,16 +567,16 @@ nf_conntrack_log_invalid_sysctl(const struct ctl_table *table, int write,
 		return ret;
 
 	if (*(u8 *)table->data == 0)
-		return ret;
+		return 0;
 
 	/* Load nf_log_syslog only if no logger is currently registered */
 	for (i = 0; i < NFPROTO_NUMPROTO; i++) {
 		if (nf_log_is_registered(i))
-			return ret;
+			return 0;
 	}
 	request_module("%s", "nf_log_syslog");
 
-	return ret;
+	return 0;
 }
 
 static struct ctl_table_header *nf_ct_netfilter_header;
diff --git a/net/netfilter/nft_set_pipapo_avx2.c b/net/netfilter/nft_set_pipapo_avx2.c
index db5d367e43c4..2f090e253caf 100644
--- a/net/netfilter/nft_set_pipapo_avx2.c
+++ b/net/netfilter/nft_set_pipapo_avx2.c
@@ -1150,12 +1150,12 @@ nft_pipapo_avx2_lookup(const struct net *net, const struct nft_set *set,
 		       const u32 *key)
 {
 	struct nft_pipapo *priv = nft_set_priv(set);
+	const struct nft_set_ext *ext = NULL;
 	struct nft_pipapo_scratch *scratch;
 	u8 genmask = nft_genmask_cur(net);
 	const struct nft_pipapo_match *m;
 	const struct nft_pipapo_field *f;
 	const u8 *rp = (const u8 *)key;
-	const struct nft_set_ext *ext;
 	unsigned long *res, *fill;
 	bool map_index;
 	int i;
@@ -1246,13 +1246,13 @@ next_match:
 			goto out;
 
 		if (last) {
-			ext = &f->mt[ret].e->ext;
-			if (unlikely(nft_set_elem_expired(ext) ||
-				     !nft_set_elem_active(ext, genmask))) {
-				ext = NULL;
+			const struct nft_set_ext *e = &f->mt[ret].e->ext;
+
+			if (unlikely(nft_set_elem_expired(e) ||
+				     !nft_set_elem_active(e, genmask)))
 				goto next_match;
-			}
 
+			ext = e;
 			goto out;
 		}
 
diff --git a/net/netfilter/nft_socket.c b/net/netfilter/nft_socket.c
index 35d0409b0095..36affbb697c2 100644
--- a/net/netfilter/nft_socket.c
+++ b/net/netfilter/nft_socket.c
@@ -217,7 +217,7 @@ static int nft_socket_init(const struct nft_ctx *ctx,
 
 		level += err;
 		/* Implies a giant cgroup tree */
-		if (WARN_ON_ONCE(level > 255))
+		if (level > 255)
 			return -EOPNOTSUPP;
 
 		priv->level = level;