Merge git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf

Florian Westphal says:

====================
netfilter: conntrack and nf_tables bug fixes

The following patchset contains netfilter fixes for net.

Broken since 5.19:
  A few ancient connection tracking helpers assume TCP packets cannot
  exceed 64kb in size, but this isn't the case anymore with 5.19 when
  BIG TCP got merged, from myself.

Regressions since 5.19:
  1. 'conntrack -E expect' won't display anything because nfnetlink failed
     to enable events for expectations, only for normal conntrack events.

  2. partially revert change that added resched calls to a function that can
     be in atomic context.  Both broken and fixed up by myself.

Broken for several releases (up to original merge of nf_tables):
  Several fixes for nf_tables control plane, from Pablo.
  This fixes up resource leaks in error paths and adds more sanity
  checks for mutually exclusive attributes/flags.

Kconfig:
  NF_CONNTRACK_PROCFS is very old and doesn't provide all info provided
  via ctnetlink, so it should not default to y. From Geert Uytterhoeven.

Selftests:
  rework nft_flowtable.sh: it frequently indicated failure; the way it
  tried to detect an offload failure did not work reliably.

* git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  testing: selftests: nft_flowtable.sh: rework test to detect offload failure
  testing: selftests: nft_flowtable.sh: use random netns names
  netfilter: conntrack: NF_CONNTRACK_PROCFS should no longer default to y
  netfilter: nf_tables: check NFT_SET_CONCAT flag if field_count is specified
  netfilter: nf_tables: disallow NFT_SET_ELEM_CATCHALL and NFT_SET_ELEM_INTERVAL_END
  netfilter: nf_tables: NFTA_SET_ELEM_KEY_END requires concat and interval flags
  netfilter: nf_tables: validate NFTA_SET_ELEM_OBJREF based on NFT_SET_OBJECT flag
  netfilter: nf_tables: really skip inactive sets when allocating name
  netfilter: nfnetlink: re-enable conntrack expectation events
  netfilter: nf_tables: fix scheduling-while-atomic splat
  netfilter: nf_ct_irc: cap packet search space to 4k
  netfilter: nf_ct_ftp: prefer skb_linearize
  netfilter: nf_ct_h323: cap packet size at 64k
  netfilter: nf_ct_sane: remove pseudo skb linearization
  netfilter: nf_tables: possible module reference underflow in error path
  netfilter: nf_tables: disallow NFTA_SET_ELEM_KEY_END with NFT_SET_ELEM_INTERVAL_END flag
  netfilter: nf_tables: use READ_ONCE and WRITE_ONCE for shared generation id access
====================

Link: https://lore.kernel.org/r/20220817140015.25843-1-fw@strlen.deSigned-off-by: Jakub Kicinski <kuba@kernel.org>

include/net/netns/conntrack.h

@@ -95,7 +95,7 @@ struct nf_ip_net {
 
 struct netns_ct {
 #ifdef CONFIG_NF_CONNTRACK_EVENTS
-	bool ctnetlink_has_listener;
+	u8 ctnetlink_has_listener;
 	bool ecache_dwork_pending;
 #endif
 	u8			sysctl_log_invalid; /* Log invalid packets */

net/netfilter/Kconfig

@@ -144,7 +144,6 @@ config NF_CONNTRACK_ZONES
 
 config NF_CONNTRACK_PROCFS
 	bool "Supply CT list in procfs (OBSOLETE)"
-	default y
 	depends on PROC_FS
 	help
 	This option enables for the list of known conntrack entries

net/netfilter/nf_conntrack_ftp.c

@@ -34,11 +34,6 @@ MODULE_DESCRIPTION("ftp connection tracking helper");
 MODULE_ALIAS("ip_conntrack_ftp");
 MODULE_ALIAS_NFCT_HELPER(HELPER_NAME);
 
-/* This is slow, but it's simple. --RR */
-static char *ftp_buffer;
-
-static DEFINE_SPINLOCK(nf_ftp_lock);
-
 #define MAX_PORTS 8
 static u_int16_t ports[MAX_PORTS];
 static unsigned int ports_c;
@@ -398,6 +393,9 @@ static int help(struct sk_buff *skb,
 		return NF_ACCEPT;
 	}
 
+	if (unlikely(skb_linearize(skb)))
+		return NF_DROP;
+
 	th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph);
 	if (th == NULL)
 		return NF_ACCEPT;
@@ -411,12 +409,8 @@ static int help(struct sk_buff *skb,
 	}
 	datalen = skb->len - dataoff;
 
-	spin_lock_bh(&nf_ftp_lock);
-	fb_ptr = skb_header_pointer(skb, dataoff, datalen, ftp_buffer);
-	if (!fb_ptr) {
-		spin_unlock_bh(&nf_ftp_lock);
-		return NF_ACCEPT;
-	}
+	spin_lock_bh(&ct->lock);
+	fb_ptr = skb->data + dataoff;
 
 	ends_in_nl = (fb_ptr[datalen - 1] == '\n');
 	seq = ntohl(th->seq) + datalen;
@@ -544,7 +538,7 @@ static int help(struct sk_buff *skb,
 	if (ends_in_nl)
 		update_nl_seq(ct, seq, ct_ftp_info, dir, skb);
  out:
-	spin_unlock_bh(&nf_ftp_lock);
+	spin_unlock_bh(&ct->lock);
 	return ret;
 }
 
@@ -571,7 +565,6 @@ static const struct nf_conntrack_expect_policy ftp_exp_policy = {
 static void __exit nf_conntrack_ftp_fini(void)
 {
 	nf_conntrack_helpers_unregister(ftp, ports_c * 2);
-	kfree(ftp_buffer);
 }
 
 static int __init nf_conntrack_ftp_init(void)
@@ -580,10 +573,6 @@ static int __init nf_conntrack_ftp_init(void)
 
 	NF_CT_HELPER_BUILD_BUG_ON(sizeof(struct nf_ct_ftp_master));
 
-	ftp_buffer = kmalloc(65536, GFP_KERNEL);
-	if (!ftp_buffer)
-		return -ENOMEM;
-
 	if (ports_c == 0)
 		ports[ports_c++] = FTP_PORT;
 
@@ -603,7 +592,6 @@ static int __init nf_conntrack_ftp_init(void)
 	ret = nf_conntrack_helpers_register(ftp, ports_c * 2);
 	if (ret < 0) {
 		pr_err("failed to register helpers\n");
-		kfree(ftp_buffer);
 		return ret;
 	}
 

net/netfilter/nf_conntrack_h323_main.c

@@ -34,6 +34,8 @@
 #include <net/netfilter/nf_conntrack_zones.h>
 #include <linux/netfilter/nf_conntrack_h323.h>
 
+#define H323_MAX_SIZE 65535
+
 /* Parameters */
 static unsigned int default_rrq_ttl __read_mostly = 300;
 module_param(default_rrq_ttl, uint, 0600);
@@ -86,6 +88,9 @@ static int get_tpkt_data(struct sk_buff *skb, unsigned int protoff,
 	if (tcpdatalen <= 0)	/* No TCP data */
 		goto clear_out;
 
+	if (tcpdatalen > H323_MAX_SIZE)
+		tcpdatalen = H323_MAX_SIZE;
+
 	if (*data == NULL) {	/* first TPKT */
 		/* Get first TPKT pointer */
 		tpkt = skb_header_pointer(skb, tcpdataoff, tcpdatalen,
@@ -1169,6 +1174,9 @@ static unsigned char *get_udp_data(struct sk_buff *skb, unsigned int protoff,
 	if (dataoff >= skb->len)
 		return NULL;
 	*datalen = skb->len - dataoff;
+	if (*datalen > H323_MAX_SIZE)
+		*datalen = H323_MAX_SIZE;
+
 	return skb_header_pointer(skb, dataoff, *datalen, h323_buffer);
 }
 
@@ -1770,7 +1778,7 @@ static int __init nf_conntrack_h323_init(void)
 
 	NF_CT_HELPER_BUILD_BUG_ON(sizeof(struct nf_ct_h323_master));
 
-	h323_buffer = kmalloc(65536, GFP_KERNEL);
+	h323_buffer = kmalloc(H323_MAX_SIZE + 1, GFP_KERNEL);
 	if (!h323_buffer)
 		return -ENOMEM;
 	ret = h323_helper_init();

net/netfilter/nf_conntrack_irc.c

@@ -39,6 +39,7 @@ unsigned int (*nf_nat_irc_hook)(struct sk_buff *skb,
 EXPORT_SYMBOL_GPL(nf_nat_irc_hook);
 
 #define HELPER_NAME "irc"
+#define MAX_SEARCH_SIZE	4095
 
 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
 MODULE_DESCRIPTION("IRC (DCC) connection tracking helper");
@@ -121,6 +122,7 @@ static int help(struct sk_buff *skb, unsigned int protoff,
 	int i, ret = NF_ACCEPT;
 	char *addr_beg_p, *addr_end_p;
 	typeof(nf_nat_irc_hook) nf_nat_irc;
+	unsigned int datalen;
 
 	/* If packet is coming from IRC server */
 	if (dir == IP_CT_DIR_REPLY)
@@ -140,8 +142,12 @@ static int help(struct sk_buff *skb, unsigned int protoff,
 	if (dataoff >= skb->len)
 		return NF_ACCEPT;
 
+	datalen = skb->len - dataoff;
+	if (datalen > MAX_SEARCH_SIZE)
+		datalen = MAX_SEARCH_SIZE;
+
 	spin_lock_bh(&irc_buffer_lock);
-	ib_ptr = skb_header_pointer(skb, dataoff, skb->len - dataoff,
+	ib_ptr = skb_header_pointer(skb, dataoff, datalen,
 				    irc_buffer);
 	if (!ib_ptr) {
 		spin_unlock_bh(&irc_buffer_lock);
@@ -149,7 +155,7 @@ static int help(struct sk_buff *skb, unsigned int protoff,
 	}
 
 	data = ib_ptr;
-	data_limit = ib_ptr + skb->len - dataoff;
+	data_limit = ib_ptr + datalen;
 
 	/* strlen("\1DCC SENT t AAAAAAAA P\1\n")=24
 	 * 5+MINMATCHLEN+strlen("t AAAAAAAA P\1\n")=14 */
@@ -251,7 +257,7 @@ static int __init nf_conntrack_irc_init(void)
 	irc_exp_policy.max_expected = max_dcc_channels;
 	irc_exp_policy.timeout = dcc_timeout;
 
-	irc_buffer = kmalloc(65536, GFP_KERNEL);
+	irc_buffer = kmalloc(MAX_SEARCH_SIZE + 1, GFP_KERNEL);
 	if (!irc_buffer)
 		return -ENOMEM;
 

net/netfilter/nf_conntrack_sane.c

@@ -34,10 +34,6 @@ MODULE_AUTHOR("Michal Schmidt <mschmidt@redhat.com>");
 MODULE_DESCRIPTION("SANE connection tracking helper");
 MODULE_ALIAS_NFCT_HELPER(HELPER_NAME);
 
-static char *sane_buffer;
-
-static DEFINE_SPINLOCK(nf_sane_lock);
-
 #define MAX_PORTS 8
 static u_int16_t ports[MAX_PORTS];
 static unsigned int ports_c;
@@ -67,14 +63,16 @@ static int help(struct sk_buff *skb,
 	unsigned int dataoff, datalen;
 	const struct tcphdr *th;
 	struct tcphdr _tcph;
-	void *sb_ptr;
 	int ret = NF_ACCEPT;
 	int dir = CTINFO2DIR(ctinfo);
 	struct nf_ct_sane_master *ct_sane_info = nfct_help_data(ct);
 	struct nf_conntrack_expect *exp;
 	struct nf_conntrack_tuple *tuple;
-	struct sane_request *req;
 	struct sane_reply_net_start *reply;
+	union {
+		struct sane_request req;
+		struct sane_reply_net_start repl;
+	} buf;
 
 	/* Until there's been traffic both ways, don't look in packets. */
 	if (ctinfo != IP_CT_ESTABLISHED &&
@@ -92,59 +90,62 @@ static int help(struct sk_buff *skb,
 		return NF_ACCEPT;
 
 	datalen = skb->len - dataoff;
-
-	spin_lock_bh(&nf_sane_lock);
-	sb_ptr = skb_header_pointer(skb, dataoff, datalen, sane_buffer);
-	if (!sb_ptr) {
-		spin_unlock_bh(&nf_sane_lock);
-		return NF_ACCEPT;
-	}
-
 	if (dir == IP_CT_DIR_ORIGINAL) {
+		const struct sane_request *req;
+
 		if (datalen != sizeof(struct sane_request))
-			goto out;
+			return NF_ACCEPT;
+
+		req = skb_header_pointer(skb, dataoff, datalen, &buf.req);
+		if (!req)
+			return NF_ACCEPT;
 
-		req = sb_ptr;
 		if (req->RPC_code != htonl(SANE_NET_START)) {
 			/* Not an interesting command */
-			ct_sane_info->state = SANE_STATE_NORMAL;
-			goto out;
+			WRITE_ONCE(ct_sane_info->state, SANE_STATE_NORMAL);
+			return NF_ACCEPT;
 		}
 
 		/* We're interested in the next reply */
-		ct_sane_info->state = SANE_STATE_START_REQUESTED;
-		goto out;
+		WRITE_ONCE(ct_sane_info->state, SANE_STATE_START_REQUESTED);
+		return NF_ACCEPT;
 	}
 
+	/* IP_CT_DIR_REPLY */
+
 	/* Is it a reply to an uninteresting command? */
-	if (ct_sane_info->state != SANE_STATE_START_REQUESTED)
-		goto out;
+	if (READ_ONCE(ct_sane_info->state) != SANE_STATE_START_REQUESTED)
+		return NF_ACCEPT;
 
 	/* It's a reply to SANE_NET_START. */
-	ct_sane_info->state = SANE_STATE_NORMAL;
+	WRITE_ONCE(ct_sane_info->state, SANE_STATE_NORMAL);
 
 	if (datalen < sizeof(struct sane_reply_net_start)) {
 		pr_debug("NET_START reply too short\n");
-		goto out;
+		return NF_ACCEPT;
 	}
 
-	reply = sb_ptr;
+	datalen = sizeof(struct sane_reply_net_start);
+
+	reply = skb_header_pointer(skb, dataoff, datalen, &buf.repl);
+	if (!reply)
+		return NF_ACCEPT;
+
 	if (reply->status != htonl(SANE_STATUS_SUCCESS)) {
 		/* saned refused the command */
 		pr_debug("unsuccessful SANE_STATUS = %u\n",
 			 ntohl(reply->status));
-		goto out;
+		return NF_ACCEPT;
 	}
 
 	/* Invalid saned reply? Ignore it. */
 	if (reply->zero != 0)
-		goto out;
+		return NF_ACCEPT;
 
 	exp = nf_ct_expect_alloc(ct);
 	if (exp == NULL) {
 		nf_ct_helper_log(skb, ct, "cannot alloc expectation");
-		ret = NF_DROP;
-		goto out;
+		return NF_DROP;
 	}
 
 	tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
@@ -162,9 +163,6 @@ static int help(struct sk_buff *skb,
 	}
 
 	nf_ct_expect_put(exp);
-
-out:
-	spin_unlock_bh(&nf_sane_lock);
 	return ret;
 }
 
@@ -178,7 +176,6 @@ static const struct nf_conntrack_expect_policy sane_exp_policy = {
 static void __exit nf_conntrack_sane_fini(void)
 {
 	nf_conntrack_helpers_unregister(sane, ports_c * 2);
-	kfree(sane_buffer);
 }
 
 static int __init nf_conntrack_sane_init(void)
@@ -187,10 +184,6 @@ static int __init nf_conntrack_sane_init(void)
 
 	NF_CT_HELPER_BUILD_BUG_ON(sizeof(struct nf_ct_sane_master));
 
-	sane_buffer = kmalloc(65536, GFP_KERNEL);
-	if (!sane_buffer)
-		return -ENOMEM;
-
 	if (ports_c == 0)
 		ports[ports_c++] = SANE_PORT;
 
@@ -210,7 +203,6 @@ static int __init nf_conntrack_sane_init(void)
 	ret = nf_conntrack_helpers_register(sane, ports_c * 2);
 	if (ret < 0) {
 		pr_err("failed to register helpers\n");
-		kfree(sane_buffer);
 		return ret;
 	}
 

net/netfilter/nf_tables_api.c

@@ -889,7 +889,7 @@ static int nf_tables_dump_tables(struct sk_buff *skb,
 
 	rcu_read_lock();
 	nft_net = nft_pernet(net);
-	cb->seq = nft_net->base_seq;
+	cb->seq = READ_ONCE(nft_net->base_seq);
 
 	list_for_each_entry_rcu(table, &nft_net->tables, list) {
 		if (family != NFPROTO_UNSPEC && family != table->family)
@@ -1705,7 +1705,7 @@ static int nf_tables_dump_chains(struct sk_buff *skb,
 
 	rcu_read_lock();
 	nft_net = nft_pernet(net);
-	cb->seq = nft_net->base_seq;
+	cb->seq = READ_ONCE(nft_net->base_seq);
 
 	list_for_each_entry_rcu(table, &nft_net->tables, list) {
 		if (family != NFPROTO_UNSPEC && family != table->family)
@@ -3149,7 +3149,7 @@ static int nf_tables_dump_rules(struct sk_buff *skb,
 
 	rcu_read_lock();
 	nft_net = nft_pernet(net);
-	cb->seq = nft_net->base_seq;
+	cb->seq = READ_ONCE(nft_net->base_seq);
 
 	list_for_each_entry_rcu(table, &nft_net->tables, list) {
 		if (family != NFPROTO_UNSPEC && family != table->family)
@@ -3907,7 +3907,7 @@ static int nf_tables_set_alloc_name(struct nft_ctx *ctx, struct nft_set *set,
 		list_for_each_entry(i, &ctx->table->sets, list) {
 			int tmp;
 
-			if (!nft_is_active_next(ctx->net, set))
+			if (!nft_is_active_next(ctx->net, i))
 				continue;
 			if (!sscanf(i->name, name, &tmp))
 				continue;
@@ -4133,7 +4133,7 @@ static int nf_tables_dump_sets(struct sk_buff *skb, struct netlink_callback *cb)
 
 	rcu_read_lock();
 	nft_net = nft_pernet(net);
-	cb->seq = nft_net->base_seq;
+	cb->seq = READ_ONCE(nft_net->base_seq);
 
 	list_for_each_entry_rcu(table, &nft_net->tables, list) {
 		if (ctx->family != NFPROTO_UNSPEC &&
@@ -4451,6 +4451,11 @@ static int nf_tables_newset(struct sk_buff *skb, const struct nfnl_info *info,
 		err = nf_tables_set_desc_parse(&desc, nla[NFTA_SET_DESC]);
 		if (err < 0)
 			return err;
+
+		if (desc.field_count > 1 && !(flags & NFT_SET_CONCAT))
+			return -EINVAL;
+	} else if (flags & NFT_SET_CONCAT) {
+		return -EINVAL;
 	}
 
 	if (nla[NFTA_SET_EXPR] || nla[NFTA_SET_EXPRESSIONS])
@@ -5061,6 +5066,8 @@ static int nf_tables_dump_set(struct sk_buff *skb, struct netlink_callback *cb)
 
 	rcu_read_lock();
 	nft_net = nft_pernet(net);
+	cb->seq = READ_ONCE(nft_net->base_seq);
+
 	list_for_each_entry_rcu(table, &nft_net->tables, list) {
 		if (dump_ctx->ctx.family != NFPROTO_UNSPEC &&
 		    dump_ctx->ctx.family != table->family)
@@ -5196,6 +5203,9 @@ static int nft_setelem_parse_flags(const struct nft_set *set,
 	if (!(set->flags & NFT_SET_INTERVAL) &&
 	    *flags & NFT_SET_ELEM_INTERVAL_END)
 		return -EINVAL;
+	if ((*flags & (NFT_SET_ELEM_INTERVAL_END | NFT_SET_ELEM_CATCHALL)) ==
+	    (NFT_SET_ELEM_INTERVAL_END | NFT_SET_ELEM_CATCHALL))
+		return -EINVAL;
 
 	return 0;
 }
@@ -5599,7 +5609,7 @@ int nft_set_elem_expr_clone(const struct nft_ctx *ctx, struct nft_set *set,
 
 		err = nft_expr_clone(expr, set->exprs[i]);
 		if (err < 0) {
-			nft_expr_destroy(ctx, expr);
+			kfree(expr);
 			goto err_expr;
 		}
 		expr_array[i] = expr;
@@ -5842,6 +5852,24 @@ static void nft_setelem_remove(const struct net *net,
 		set->ops->remove(net, set, elem);
 }
 
+static bool nft_setelem_valid_key_end(const struct nft_set *set,
+				      struct nlattr **nla, u32 flags)
+{
+	if ((set->flags & (NFT_SET_CONCAT | NFT_SET_INTERVAL)) ==
+			  (NFT_SET_CONCAT | NFT_SET_INTERVAL)) {
+		if (flags & NFT_SET_ELEM_INTERVAL_END)
+			return false;
+		if (!nla[NFTA_SET_ELEM_KEY_END] &&
+		    !(flags & NFT_SET_ELEM_CATCHALL))
+			return false;
+	} else {
+		if (nla[NFTA_SET_ELEM_KEY_END])
+			return false;
+	}
+
+	return true;
+}
+
 static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 			    const struct nlattr *attr, u32 nlmsg_flags)
 {
@@ -5892,6 +5920,18 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 			return -EINVAL;
 	}
 
+	if (set->flags & NFT_SET_OBJECT) {
+		if (!nla[NFTA_SET_ELEM_OBJREF] &&
+		    !(flags & NFT_SET_ELEM_INTERVAL_END))
+			return -EINVAL;
+	} else {
+		if (nla[NFTA_SET_ELEM_OBJREF])
+			return -EINVAL;
+	}
+
+	if (!nft_setelem_valid_key_end(set, nla, flags))
+		return -EINVAL;
+
 	if ((flags & NFT_SET_ELEM_INTERVAL_END) &&
 	     (nla[NFTA_SET_ELEM_DATA] ||
 	      nla[NFTA_SET_ELEM_OBJREF] ||
@@ -5899,6 +5939,7 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 	      nla[NFTA_SET_ELEM_EXPIRATION] ||
 	      nla[NFTA_SET_ELEM_USERDATA] ||
 	      nla[NFTA_SET_ELEM_EXPR] ||
+	      nla[NFTA_SET_ELEM_KEY_END] ||
 	      nla[NFTA_SET_ELEM_EXPRESSIONS]))
 		return -EINVAL;
 
@@ -6029,10 +6070,6 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 	}
 
 	if (nla[NFTA_SET_ELEM_OBJREF] != NULL) {
-		if (!(set->flags & NFT_SET_OBJECT)) {
-			err = -EINVAL;
-			goto err_parse_key_end;
-		}
 		obj = nft_obj_lookup(ctx->net, ctx->table,
 				     nla[NFTA_SET_ELEM_OBJREF],
 				     set->objtype, genmask);
@@ -6325,6 +6362,9 @@ static int nft_del_setelem(struct nft_ctx *ctx, struct nft_set *set,
 	if (!nla[NFTA_SET_ELEM_KEY] && !(flags & NFT_SET_ELEM_CATCHALL))
 		return -EINVAL;
 
+	if (!nft_setelem_valid_key_end(set, nla, flags))
+		return -EINVAL;
+
 	nft_set_ext_prepare(&tmpl);
 
 	if (flags != 0) {
@@ -6941,7 +6981,7 @@ static int nf_tables_dump_obj(struct sk_buff *skb, struct netlink_callback *cb)
 
 	rcu_read_lock();
 	nft_net = nft_pernet(net);
-	cb->seq = nft_net->base_seq;
+	cb->seq = READ_ONCE(nft_net->base_seq);
 
 	list_for_each_entry_rcu(table, &nft_net->tables, list) {
 		if (family != NFPROTO_UNSPEC && family != table->family)
@@ -7873,7 +7913,7 @@ static int nf_tables_dump_flowtable(struct sk_buff *skb,
 
 	rcu_read_lock();
 	nft_net = nft_pernet(net);
-	cb->seq = nft_net->base_seq;
+	cb->seq = READ_ONCE(nft_net->base_seq);
 
 	list_for_each_entry_rcu(table, &nft_net->tables, list) {
 		if (family != NFPROTO_UNSPEC && family != table->family)
@@ -8806,6 +8846,7 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)
 	struct nft_trans_elem *te;
 	struct nft_chain *chain;
 	struct nft_table *table;
+	unsigned int base_seq;
 	LIST_HEAD(adl);
 	int err;
 
@@ -8855,9 +8896,12 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)
 	 * Bump generation counter, invalidate any dump in progress.
 	 * Cannot fail after this point.
 	 */
-	while (++nft_net->base_seq == 0)
+	base_seq = READ_ONCE(nft_net->base_seq);
+	while (++base_seq == 0)
 		;
 
+	WRITE_ONCE(nft_net->base_seq, base_seq);
+
 	/* step 3. Start new generation, rules_gen_X now in use. */
 	net->nft.gencursor = nft_gencursor_next(net);
 
@@ -9419,13 +9463,9 @@ static int nf_tables_check_loops(const struct nft_ctx *ctx,
 				break;
 			}
 		}
-
-		cond_resched();
 	}
 
 	list_for_each_entry(set, &ctx->table->sets, list) {
-		cond_resched();
-
 		if (!nft_is_active_next(ctx->net, set))
 			continue;
 		if (!(set->flags & NFT_SET_MAP) ||

net/netfilter/nfnetlink.c

@@ -44,6 +44,10 @@ MODULE_DESCRIPTION("Netfilter messages via netlink socket");
 
 static unsigned int nfnetlink_pernet_id __read_mostly;
 
+#ifdef CONFIG_NF_CONNTRACK_EVENTS
+static DEFINE_SPINLOCK(nfnl_grp_active_lock);
+#endif
+
 struct nfnl_net {
 	struct sock *nfnl;
 };
@@ -654,6 +658,44 @@ static void nfnetlink_rcv(struct sk_buff *skb)
 		netlink_rcv_skb(skb, nfnetlink_rcv_msg);
 }
 
+static void nfnetlink_bind_event(struct net *net, unsigned int group)
+{
+#ifdef CONFIG_NF_CONNTRACK_EVENTS
+	int type, group_bit;
+	u8 v;
+
+	/* All NFNLGRP_CONNTRACK_* group bits fit into u8.
+	 * The other groups are not relevant and can be ignored.
+	 */
+	if (group >= 8)
+		return;
+
+	type = nfnl_group2type[group];
+
+	switch (type) {
+	case NFNL_SUBSYS_CTNETLINK:
+		break;
+	case NFNL_SUBSYS_CTNETLINK_EXP:
+		break;
+	default:
+		return;
+	}
+
+	group_bit = (1 << group);
+
+	spin_lock(&nfnl_grp_active_lock);
+	v = READ_ONCE(net->ct.ctnetlink_has_listener);
+	if ((v & group_bit) == 0) {
+		v |= group_bit;
+
+		/* read concurrently without nfnl_grp_active_lock held. */
+		WRITE_ONCE(net->ct.ctnetlink_has_listener, v);
+	}
+
+	spin_unlock(&nfnl_grp_active_lock);
+#endif
+}
+
 static int nfnetlink_bind(struct net *net, int group)
 {
 	const struct nfnetlink_subsystem *ss;
@@ -670,28 +712,45 @@ static int nfnetlink_bind(struct net *net, int group)
 	if (!ss)
 		request_module_nowait("nfnetlink-subsys-%d", type);
 
-#ifdef CONFIG_NF_CONNTRACK_EVENTS
-	if (type == NFNL_SUBSYS_CTNETLINK) {
-		nfnl_lock(NFNL_SUBSYS_CTNETLINK);
-		WRITE_ONCE(net->ct.ctnetlink_has_listener, true);
-		nfnl_unlock(NFNL_SUBSYS_CTNETLINK);
-	}
-#endif
+	nfnetlink_bind_event(net, group);
 	return 0;
 }
 
 static void nfnetlink_unbind(struct net *net, int group)
 {
 #ifdef CONFIG_NF_CONNTRACK_EVENTS
+	int type, group_bit;
+
 	if (group <= NFNLGRP_NONE || group > NFNLGRP_MAX)
 		return;
 
-	if (nfnl_group2type[group] == NFNL_SUBSYS_CTNETLINK) {
-		nfnl_lock(NFNL_SUBSYS_CTNETLINK);
-		if (!nfnetlink_has_listeners(net, group))
-			WRITE_ONCE(net->ct.ctnetlink_has_listener, false);
-		nfnl_unlock(NFNL_SUBSYS_CTNETLINK);
+	type = nfnl_group2type[group];
+
+	switch (type) {
+	case NFNL_SUBSYS_CTNETLINK:
+		break;
+	case NFNL_SUBSYS_CTNETLINK_EXP:
+		break;
+	default:
+		return;
+	}
+
+	/* ctnetlink_has_listener is u8 */
+	if (group >= 8)
+		return;
+
+	group_bit = (1 << group);
+
+	spin_lock(&nfnl_grp_active_lock);
+	if (!nfnetlink_has_listeners(net, group)) {
+		u8 v = READ_ONCE(net->ct.ctnetlink_has_listener);
+
+		v &= ~group_bit;
+
+		/* read concurrently without nfnl_grp_active_lock held. */
+		WRITE_ONCE(net->ct.ctnetlink_has_listener, v);
 	}
+	spin_unlock(&nfnl_grp_active_lock);
 #endif
 }