Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next

Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

The following patchset contains Netfilter updates for net-next:

1) Use nf_flow_offload_tuple() to fetch flow stats, from Paul Blakey.

2) Add new xt_IDLETIMER hard mode, from Manoj Basapathi.
   Follow up patch to clean up this new mode, from Dan Carpenter.

3) Add support for geneve tunnel options, from Xin Long.

4) Make sets built-in and remove modular infrastructure for sets,
   from Florian Westphal.

5) Remove unused TEMPLATE_NULLS_VAL, from Li RongQing.

6) Statify nft_pipapo_get, from Chen Wandun.

7) Use C99 flexible-array member, from Gustavo A. R. Silva.

8) More descriptive variable names for bitwise, from Jeremy Sowden.

9) Four patches to add tunnel device hardware offload to the flowtable
   infrastructure, from wenxu.

10) pipapo set supports for 8-bit grouping, from Stefano Brivio.

11) pipapo can switch between nibble and byte grouping, also from
    Stefano.

12) Add AVX2 vectorized version of pipapo, from Stefano Brivio.

13) Update pipapo to be use it for single ranges, from Stefano.

14) Add stateful expression support to elements via control plane,
    eg. counter per element.

15) Re-visit sysctls in unprivileged namespaces, from Florian Westphal.

15) Add new egress hook, from Lukas Wunner.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

18 files changed, 172 insertions, 92 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 654808bfad83..15f1e32b430c 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1751,6 +1751,7 @@ enum netdev_priv_flags {
  *	@xps_maps:	XXX: need comments on this one
  *	@miniq_egress:		clsact qdisc specific data for
  *				egress processing
+ *	@nf_hooks_egress:	netfilter hooks executed for egress packets
  *	@qdisc_hash:		qdisc hash table
  *	@watchdog_timeo:	Represents the timeout that is used by
  *				the watchdog (see dev_watchdog())
@@ -2026,6 +2027,9 @@ struct net_device {
 #ifdef CONFIG_NET_CLS_ACT
 	struct mini_Qdisc __rcu	*miniq_egress;
 #endif
+#ifdef CONFIG_NETFILTER_EGRESS
+	struct nf_hook_entries __rcu *nf_hooks_egress;
+#endif
 
 #ifdef CONFIG_NET_SCHED
 	DECLARE_HASHTABLE	(qdisc_hash, 4);
diff --git a/include/linux/netfilter/ipset/ip_set.h b/include/linux/netfilter/ipset/ip_set.h
index 5448c8b443db..ab192720e2d6 100644
--- a/include/linux/netfilter/ipset/ip_set.h
+++ b/include/linux/netfilter/ipset/ip_set.h
@@ -98,7 +98,7 @@ struct ip_set_counter {
 
 struct ip_set_comment_rcu {
 	struct rcu_head rcu;
-	char str[0];
+	char str[];
 };
 
 struct ip_set_comment {
diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
index 1b261c51b3a3..5da88451853b 100644
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -264,7 +264,7 @@ struct xt_table_info {
 	unsigned int stacksize;
 	void ***jumpstack;
 
-	unsigned char entries[0] __aligned(8);
+	unsigned char entries[] __aligned(8);
 };
 
 int xt_register_target(struct xt_target *target);
@@ -464,7 +464,7 @@ struct compat_xt_entry_match {
 		} kernel;
 		u_int16_t match_size;
 	} u;
-	unsigned char data[0];
+	unsigned char data[];
 };
 
 struct compat_xt_entry_target {
@@ -480,7 +480,7 @@ struct compat_xt_entry_target {
 		} kernel;
 		u_int16_t target_size;
 	} u;
-	unsigned char data[0];
+	unsigned char data[];
 };
 
 /* FIXME: this works only on 32 bit tasks
@@ -494,7 +494,7 @@ struct compat_xt_counters {
 struct compat_xt_counters_info {
 	char name[XT_TABLE_MAXNAMELEN];
 	compat_uint_t num_counters;
-	struct compat_xt_counters counters[0];
+	struct compat_xt_counters counters[];
 };
 
 struct _compat_xt_align {
diff --git a/include/linux/netfilter_arp/arp_tables.h b/include/linux/netfilter_arp/arp_tables.h
index e98028f00e47..7d3537c40ec9 100644
--- a/include/linux/netfilter_arp/arp_tables.h
+++ b/include/linux/netfilter_arp/arp_tables.h
@@ -67,7 +67,7 @@ struct compat_arpt_entry {
 	__u16 next_offset;
 	compat_uint_t comefrom;
 	struct compat_xt_counters counters;
-	unsigned char elems[0];
+	unsigned char elems[];
 };
 
 static inline struct xt_entry_target *
diff --git a/include/linux/netfilter_bridge/ebtables.h b/include/linux/netfilter_bridge/ebtables.h
index 162f59d0d17a..2f5c4e6ecd8a 100644
--- a/include/linux/netfilter_bridge/ebtables.h
+++ b/include/linux/netfilter_bridge/ebtables.h
@@ -85,7 +85,7 @@ struct ebt_table_info {
 	/* room to maintain the stack used for jumping from and into udc */
 	struct ebt_chainstack **chainstack;
 	char *entries;
-	struct ebt_counter counters[0] ____cacheline_aligned;
+	struct ebt_counter counters[] ____cacheline_aligned;
 };
 
 struct ebt_table {
diff --git a/include/linux/netfilter_ingress.h b/include/linux/netfilter_ingress.h
deleted file mode 100644
index a13774be2eb5..000000000000
--- a/include/linux/netfilter_ingress.h
+++ /dev/null
@@ -1,58 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _NETFILTER_INGRESS_H_
-#define _NETFILTER_INGRESS_H_
-
-#include <linux/netfilter.h>
-#include <linux/netdevice.h>
-
-#ifdef CONFIG_NETFILTER_INGRESS
-static inline bool nf_hook_ingress_active(const struct sk_buff *skb)
-{
-#ifdef CONFIG_JUMP_LABEL
-	if (!static_key_false(&nf_hooks_needed[NFPROTO_NETDEV][NF_NETDEV_INGRESS]))
-		return false;
-#endif
-	return rcu_access_pointer(skb->dev->nf_hooks_ingress);
-}
-
-/* caller must hold rcu_read_lock */
-static inline int nf_hook_ingress(struct sk_buff *skb)
-{
-	struct nf_hook_entries *e = rcu_dereference(skb->dev->nf_hooks_ingress);
-	struct nf_hook_state state;
-	int ret;
-
-	/* Must recheck the ingress hook head, in the event it became NULL
-	 * after the check in nf_hook_ingress_active evaluated to true.
-	 */
-	if (unlikely(!e))
-		return 0;
-
-	nf_hook_state_init(&state, NF_NETDEV_INGRESS,
-			   NFPROTO_NETDEV, skb->dev, NULL, NULL,
-			   dev_net(skb->dev), NULL);
-	ret = nf_hook_slow(skb, &state, e, 0);
-	if (ret == 0)
-		return -1;
-
-	return ret;
-}
-
-static inline void nf_hook_ingress_init(struct net_device *dev)
-{
-	RCU_INIT_POINTER(dev->nf_hooks_ingress, NULL);
-}
-#else /* CONFIG_NETFILTER_INGRESS */
-static inline int nf_hook_ingress_active(struct sk_buff *skb)
-{
-	return 0;
-}
-
-static inline int nf_hook_ingress(struct sk_buff *skb)
-{
-	return 0;
-}
-
-static inline void nf_hook_ingress_init(struct net_device *dev) {}
-#endif /* CONFIG_NETFILTER_INGRESS */
-#endif /* _NETFILTER_INGRESS_H_ */
diff --git a/include/linux/netfilter_ipv4/ip_tables.h b/include/linux/netfilter_ipv4/ip_tables.h
index e9e1ed74cdf1..b394bd4f68a3 100644
--- a/include/linux/netfilter_ipv4/ip_tables.h
+++ b/include/linux/netfilter_ipv4/ip_tables.h
@@ -76,7 +76,7 @@ struct compat_ipt_entry {
 	__u16 next_offset;
 	compat_uint_t comefrom;
 	struct compat_xt_counters counters;
-	unsigned char elems[0];
+	unsigned char elems[];
 };
 
 /* Helper functions */
diff --git a/include/linux/netfilter_ipv6/ip6_tables.h b/include/linux/netfilter_ipv6/ip6_tables.h
index 78ab959c4575..8225f7821a29 100644
--- a/include/linux/netfilter_ipv6/ip6_tables.h
+++ b/include/linux/netfilter_ipv6/ip6_tables.h
@@ -43,7 +43,7 @@ struct compat_ip6t_entry {
 	__u16 next_offset;
 	compat_uint_t comefrom;
 	struct compat_xt_counters counters;
-	unsigned char elems[0];
+	unsigned char elems[];
 };
 
 static inline struct xt_entry_target *
diff --git a/include/linux/netfilter_netdev.h b/include/linux/netfilter_netdev.h
new file mode 100644
index 000000000000..92d3611a782e
--- /dev/null
+++ b/include/linux/netfilter_netdev.h
@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _NETFILTER_NETDEV_H_
+#define _NETFILTER_NETDEV_H_
+
+#include <linux/netfilter.h>
+#include <linux/netdevice.h>
+
+#ifdef CONFIG_NETFILTER
+static __always_inline bool nf_hook_netdev_active(enum nf_dev_hooks hooknum,
+					  struct nf_hook_entries __rcu *hooks)
+{
+#ifdef CONFIG_JUMP_LABEL
+	if (!static_key_false(&nf_hooks_needed[NFPROTO_NETDEV][hooknum]))
+		return false;
+#endif
+	return rcu_access_pointer(hooks);
+}
+
+/* caller must hold rcu_read_lock */
+static __always_inline int nf_hook_netdev(struct sk_buff *skb,
+					  enum nf_dev_hooks hooknum,
+					  struct nf_hook_entries __rcu *hooks)
+{
+	struct nf_hook_entries *e = rcu_dereference(hooks);
+	struct nf_hook_state state;
+	int ret;
+
+	/* Must recheck the hook head, in the event it became NULL
+	 * after the check in nf_hook_netdev_active evaluated to true.
+	 */
+	if (unlikely(!e))
+		return 0;
+
+	nf_hook_state_init(&state, hooknum,
+			   NFPROTO_NETDEV, skb->dev, NULL, NULL,
+			   dev_net(skb->dev), NULL);
+	ret = nf_hook_slow(skb, &state, e, 0);
+	if (ret == 0)
+		return -1;
+
+	return ret;
+}
+#endif /* CONFIG_NETFILTER */
+
+static inline void nf_hook_netdev_init(struct net_device *dev)
+{
+#ifdef CONFIG_NETFILTER_INGRESS
+	RCU_INIT_POINTER(dev->nf_hooks_ingress, NULL);
+#endif
+#ifdef CONFIG_NETFILTER_EGRESS
+	RCU_INIT_POINTER(dev->nf_hooks_egress, NULL);
+#endif
+}
+
+#ifdef CONFIG_NETFILTER_INGRESS
+static inline bool nf_hook_ingress_active(const struct sk_buff *skb)
+{
+	return nf_hook_netdev_active(NF_NETDEV_INGRESS,
+				     skb->dev->nf_hooks_ingress);
+}
+
+static inline int nf_hook_ingress(struct sk_buff *skb)
+{
+	return nf_hook_netdev(skb, NF_NETDEV_INGRESS,
+			      skb->dev->nf_hooks_ingress);
+}
+#else /* CONFIG_NETFILTER_INGRESS */
+static inline int nf_hook_ingress_active(struct sk_buff *skb)
+{
+	return 0;
+}
+
+static inline int nf_hook_ingress(struct sk_buff *skb)
+{
+	return 0;
+}
+#endif /* CONFIG_NETFILTER_INGRESS */
+
+#ifdef CONFIG_NETFILTER_EGRESS
+static inline bool nf_hook_egress_active(const struct sk_buff *skb)
+{
+	return nf_hook_netdev_active(NF_NETDEV_EGRESS,
+				     skb->dev->nf_hooks_egress);
+}
+
+static inline int nf_hook_egress(struct sk_buff *skb)
+{
+	return nf_hook_netdev(skb, NF_NETDEV_EGRESS,
+			      skb->dev->nf_hooks_egress);
+}
+#else /* CONFIG_NETFILTER_EGRESS */
+static inline int nf_hook_egress_active(struct sk_buff *skb)
+{
+	return 0;
+}
+
+static inline int nf_hook_egress(struct sk_buff *skb)
+{
+	return 0;
+}
+#endif /* CONFIG_NETFILTER_EGRESS */
+#endif /* _NETFILTER_INGRESS_H_ */
diff --git a/include/net/netfilter/nf_conntrack_extend.h b/include/net/netfilter/nf_conntrack_extend.h
index 5ae5295aa46d..e1e588387103 100644
--- a/include/net/netfilter/nf_conntrack_extend.h
+++ b/include/net/netfilter/nf_conntrack_extend.h
@@ -45,7 +45,7 @@ enum nf_ct_ext_id {
 struct nf_ct_ext {
 	u8 offset[NF_CT_EXT_NUM];
 	u8 len;
-	char data[0];
+	char data[];
 };
 
 static inline bool __nf_ct_ext_exist(const struct nf_ct_ext *ext, u8 id)
diff --git a/include/net/netfilter/nf_conntrack_timeout.h b/include/net/netfilter/nf_conntrack_timeout.h
index 6dd72396f534..659b0ea25b4d 100644
--- a/include/net/netfilter/nf_conntrack_timeout.h
+++ b/include/net/netfilter/nf_conntrack_timeout.h
@@ -14,7 +14,7 @@
 struct nf_ct_timeout {
 	__u16			l3num;
 	const struct nf_conntrack_l4proto *l4proto;
-	char			data[0];
+	char			data[];
 };
 
 struct ctnl_timeout {
diff --git a/include/net/netfilter/nf_flow_table.h b/include/net/netfilter/nf_flow_table.h
index 6890f1ca3e31..f523ea87b6ae 100644
--- a/include/net/netfilter/nf_flow_table.h
+++ b/include/net/netfilter/nf_flow_table.h
@@ -19,11 +19,17 @@ enum flow_offload_tuple_dir;
 struct nf_flow_key {
 	struct flow_dissector_key_meta			meta;
 	struct flow_dissector_key_control		control;
+	struct flow_dissector_key_control		enc_control;
 	struct flow_dissector_key_basic			basic;
 	union {
 		struct flow_dissector_key_ipv4_addrs	ipv4;
 		struct flow_dissector_key_ipv6_addrs	ipv6;
 	};
+	struct flow_dissector_key_keyid			enc_key_id;
+	union {
+		struct flow_dissector_key_ipv4_addrs	enc_ipv4;
+		struct flow_dissector_key_ipv6_addrs	enc_ipv6;
+	};
 	struct flow_dissector_key_tcp			tcp;
 	struct flow_dissector_key_ports			tp;
 } __aligned(BITS_PER_LONG / 8); /* Ensure that we can do comparisons as longs. */
diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 4170c033d461..5d80e09f8148 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -224,7 +224,7 @@ int nft_validate_register_store(const struct nft_ctx *ctx,
  */
 struct nft_userdata {
 	u8			len;
-	unsigned char		data[0];
+	unsigned char		data[];
 };
 
 /**
@@ -385,21 +385,14 @@ struct nft_set_ops {
  *      struct nft_set_type - nf_tables set type
  *
  *      @ops: set ops for this type
- *      @list: used internally
- *      @owner: module reference
  *      @features: features supported by the implementation
  */
 struct nft_set_type {
 	const struct nft_set_ops	ops;
-	struct list_head		list;
-	struct module			*owner;
 	u32				features;
 };
 #define to_set_type(o) container_of(o, struct nft_set_type, ops)
 
-int nft_register_set(struct nft_set_type *type);
-void nft_unregister_set(struct nft_set_type *type);
-
 /**
  * 	struct nft_set - nf_tables set instance
  *
@@ -572,7 +565,7 @@ struct nft_set_ext_tmpl {
 struct nft_set_ext {
 	u8	genmask;
 	u8	offset[NFT_SET_EXT_NUM];
-	char	data[0];
+	char	data[];
 };
 
 static inline void nft_set_ext_prepare(struct nft_set_ext_tmpl *tmpl)
@@ -673,6 +666,10 @@ static inline struct nft_object **nft_set_ext_obj(const struct nft_set_ext *ext)
 	return nft_set_ext(ext, NFT_SET_EXT_OBJREF);
 }
 
+struct nft_expr *nft_set_elem_expr_alloc(const struct nft_ctx *ctx,
+					 const struct nft_set *set,
+					 const struct nlattr *attr);
+
 void *nft_set_elem_init(const struct nft_set *set,
 			const struct nft_set_ext_tmpl *tmpl,
 			const u32 *key, const u32 *key_end, const u32 *data,
@@ -849,8 +846,6 @@ static inline void *nft_expr_priv(const struct nft_expr *expr)
 	return (void *)expr->data;
 }
 
-struct nft_expr *nft_expr_init(const struct nft_ctx *ctx,
-			       const struct nlattr *nla);
 void nft_expr_destroy(const struct nft_ctx *ctx, struct nft_expr *expr);
 int nft_expr_dump(struct sk_buff *skb, unsigned int attr,
 		  const struct nft_expr *expr);
@@ -895,6 +890,18 @@ static inline struct nft_userdata *nft_userdata(const struct nft_rule *rule)
 	return (void *)&rule->data[rule->dlen];
 }
 
+static inline void nft_set_elem_update_expr(const struct nft_set_ext *ext,
+					    struct nft_regs *regs,
+					    const struct nft_pktinfo *pkt)
+{
+	struct nft_expr *expr;
+
+	if (nft_set_ext_exists(ext, NFT_SET_EXT_EXPR)) {
+		expr = nft_set_ext_expr(ext);
+		expr->ops->eval(expr, regs, pkt);
+	}
+}
+
 /*
  * The last pointer isn't really necessary, but the compiler isn't able to
  * determine that the result of nft_expr_last() is always the same since it
@@ -1253,9 +1260,6 @@ void nft_trace_notify(struct nft_traceinfo *info);
 #define MODULE_ALIAS_NFT_EXPR(name) \
 	MODULE_ALIAS("nft-expr-" name)
 
-#define MODULE_ALIAS_NFT_SET() \
-	MODULE_ALIAS("nft-set")
-
 #define MODULE_ALIAS_NFT_OBJ(type) \
 	MODULE_ALIAS("nft-obj-" __stringify(type))
 
@@ -1385,7 +1389,7 @@ struct nft_trans {
 	int				msg_type;
 	bool				put_net;
 	struct nft_ctx			ctx;
-	char				data[0];
+	char				data[];
 };
 
 struct nft_trans_rule {
diff --git a/include/net/netfilter/nf_tables_core.h b/include/net/netfilter/nf_tables_core.h
index 29e7e1021267..78516de14d31 100644
--- a/include/net/netfilter/nf_tables_core.h
+++ b/include/net/netfilter/nf_tables_core.h
@@ -69,12 +69,13 @@ extern const struct nft_expr_ops nft_payload_fast_ops;
 extern struct static_key_false nft_counters_enabled;
 extern struct static_key_false nft_trace_enabled;
 
-extern struct nft_set_type nft_set_rhash_type;
-extern struct nft_set_type nft_set_hash_type;
-extern struct nft_set_type nft_set_hash_fast_type;
-extern struct nft_set_type nft_set_rbtree_type;
-extern struct nft_set_type nft_set_bitmap_type;
-extern struct nft_set_type nft_set_pipapo_type;
+extern const struct nft_set_type nft_set_rhash_type;
+extern const struct nft_set_type nft_set_hash_type;
+extern const struct nft_set_type nft_set_hash_fast_type;
+extern const struct nft_set_type nft_set_rbtree_type;
+extern const struct nft_set_type nft_set_bitmap_type;
+extern const struct nft_set_type nft_set_pipapo_type;
+extern const struct nft_set_type nft_set_pipapo_avx2_type;
 
 struct nft_expr;
 struct nft_regs;
diff --git a/include/uapi/linux/netfilter.h b/include/uapi/linux/netfilter.h
index ca9e63d6e0e4..d1616574c54f 100644
--- a/include/uapi/linux/netfilter.h
+++ b/include/uapi/linux/netfilter.h
@@ -50,6 +50,7 @@ enum nf_inet_hooks {
 
 enum nf_dev_hooks {
 	NF_NETDEV_INGRESS,
+	NF_NETDEV_EGRESS,
 	NF_NETDEV_NUMHOOKS
 };
 
diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index 065218a20bb7..9c3d2d04d6a1 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -1770,6 +1770,7 @@ enum nft_tunnel_opts_attributes {
 	NFTA_TUNNEL_KEY_OPTS_UNSPEC,
 	NFTA_TUNNEL_KEY_OPTS_VXLAN,
 	NFTA_TUNNEL_KEY_OPTS_ERSPAN,
+	NFTA_TUNNEL_KEY_OPTS_GENEVE,
 	__NFTA_TUNNEL_KEY_OPTS_MAX
 };
 #define NFTA_TUNNEL_KEY_OPTS_MAX	(__NFTA_TUNNEL_KEY_OPTS_MAX - 1)
@@ -1791,6 +1792,15 @@ enum nft_tunnel_opts_erspan_attributes {
 };
 #define NFTA_TUNNEL_KEY_ERSPAN_MAX	(__NFTA_TUNNEL_KEY_ERSPAN_MAX - 1)
 
+enum nft_tunnel_opts_geneve_attributes {
+	NFTA_TUNNEL_KEY_GENEVE_UNSPEC,
+	NFTA_TUNNEL_KEY_GENEVE_CLASS,
+	NFTA_TUNNEL_KEY_GENEVE_TYPE,
+	NFTA_TUNNEL_KEY_GENEVE_DATA,
+	__NFTA_TUNNEL_KEY_GENEVE_MAX
+};
+#define NFTA_TUNNEL_KEY_GENEVE_MAX	(__NFTA_TUNNEL_KEY_GENEVE_MAX - 1)
+
 enum nft_tunnel_flags {
 	NFT_TUNNEL_F_ZERO_CSUM_TX	= (1 << 0),
 	NFT_TUNNEL_F_DONT_FRAGMENT	= (1 << 1),
diff --git a/include/uapi/linux/netfilter/xt_IDLETIMER.h b/include/uapi/linux/netfilter/xt_IDLETIMER.h
index 3c586a19baea..434e6506abaa 100644
--- a/include/uapi/linux/netfilter/xt_IDLETIMER.h
+++ b/include/uapi/linux/netfilter/xt_IDLETIMER.h
@@ -1,4 +1,3 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
 /*
  * linux/include/linux/netfilter/xt_IDLETIMER.h
  *
@@ -33,6 +32,7 @@
 #include <linux/types.h>
 
 #define MAX_IDLETIMER_LABEL_SIZE 28
+#define XT_IDLETIMER_ALARM 0x01
 
 struct idletimer_tg_info {
 	__u32 timeout;
@@ -43,4 +43,14 @@ struct idletimer_tg_info {
 	struct idletimer_tg *timer __attribute__((aligned(8)));
 };
 
+struct idletimer_tg_info_v1 {
+	__u32 timeout;
+
+	char label[MAX_IDLETIMER_LABEL_SIZE];
+
+	__u8 timer_type;
+
+	/* for kernel module internal use only */
+	struct idletimer_tg *timer __attribute__((aligned(8)));
+};
 #endif
diff --git a/include/uapi/linux/netfilter_bridge/ebt_among.h b/include/uapi/linux/netfilter_bridge/ebt_among.h
index 9acf757bc1f7..73b26a280c4f 100644
--- a/include/uapi/linux/netfilter_bridge/ebt_among.h
+++ b/include/uapi/linux/netfilter_bridge/ebt_among.h
@@ -40,7 +40,7 @@ struct ebt_mac_wormhash_tuple {
 struct ebt_mac_wormhash {
 	int table[257];
 	int poolsize;
-	struct ebt_mac_wormhash_tuple pool[0];
+	struct ebt_mac_wormhash_tuple pool[];
 };
 
 #define ebt_mac_wormhash_size(x) ((x) ? sizeof(struct ebt_mac_wormhash) \