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

Pablo Neira Ayuso says:

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

The following patchset contains Netfilter fixes for you net tree,
they are:

1) There was a race condition between parallel save/swap and delete,
which resulted a kernel crash due to the increase ref for save, swap,
wrong ref decrease operations. Reported and fixed by Vishwanath Pai.

2) OVS should call into CT NAT for packets of new expected connections only
when the conntrack state is persisted with the 'commit' option to the
OVS CT action. From Jarno Rajahalme.

3) Resolve kconfig dependencies with new OVS NAT support. From Arnd Bergmann.

4) Early validation of entry->target_offset to make sure it doesn't take us
out from the blob, from Florian Westphal.

5) Again early validation of entry->next_offset to make sure it doesn't take
out from the blob, also from Florian.

6) Check that entry->target_offset is always of of sizeof(struct xt_entry)
for unconditional entries, when checking both from check_underflow()
and when checking for loops in mark_source_chains(), again from
Florian.

7) Fix inconsistent behaviour in nfnetlink_queue when
NFQA_CFG_F_FAIL_OPEN is set and netlink_unicast() fails due to buffer
overrun, we have to reinject the packet as the user expects.

8) Enforce nul-terminated table names from getsockopt GET_ENTRIES
requests.

9) Don't assume skb->sk is set from nft_bridge_reject and synproxy,
this fixes a recent update of the code to namespaceify
ip_default_ttl, patch from Liping Zhang.

This batch comes with four patches to validate x_tables blobs coming
from userspace. CONFIG_USERNS exposes the x_tables interface to
unpriviledged users and to be honest this interface never received the
attention for this move away from the CAP_NET_ADMIN domain. Florian is
working on another round with more patches with more sanity checks, so
expect a bit more Netfilter fixes in this development cycle than usual.
====================

Signed-off-by: David S. Miller <[e-mail]>

include/linux/netfilter/ipset/ip_set.h

···
 	spinlock_t lock;
 	/* References to the set */
 	u32 ref;
+	/* References to the set for netlink events like dump,
+	 * ref can be swapped out by ip_set_swap
+	 */
+	u32 ref_netlink;
 	/* The core set type */
 	struct ip_set_type *type;
 	/* The type variant doing the real job */

net/bridge/netfilter/ebtables.c

···
 	if (copy_from_user(&tmp, user, sizeof(tmp)))
 		return -EFAULT;
 
+	tmp.name[sizeof(tmp.name) - 1] = '\0';
+
 	t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
 	if (!t)
 		return ret;
···
 
 	if (copy_from_user(&tmp, user, sizeof(tmp)))
 		return -EFAULT;
+
+	tmp.name[sizeof(tmp.name) - 1] = '\0';
 
 	t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
 	if (!t)

net/bridge/netfilter/nft_reject_bridge.c

···
 /* We cannot use oldskb->dev, it can be either bridge device (NF_BRIDGE INPUT)
  * or the bridge port (NF_BRIDGE PREROUTING).
  */
-static void nft_reject_br_send_v4_tcp_reset(struct sk_buff *oldskb,
+static void nft_reject_br_send_v4_tcp_reset(struct net *net,
+					    struct sk_buff *oldskb,
 					    const struct net_device *dev,
 					    int hook)
 {
···
 	struct iphdr *niph;
 	const struct tcphdr *oth;
 	struct tcphdr _oth;
-	struct net *net = sock_net(oldskb->sk);
 
 	if (!nft_bridge_iphdr_validate(oldskb))
 		return;
···
 	br_deliver(br_port_get_rcu(dev), nskb);
 }
 
-static void nft_reject_br_send_v4_unreach(struct sk_buff *oldskb,
+static void nft_reject_br_send_v4_unreach(struct net *net,
+					  struct sk_buff *oldskb,
 					  const struct net_device *dev,
 					  int hook, u8 code)
 {
···
 	void *payload;
 	__wsum csum;
 	u8 proto;
-	struct net *net = sock_net(oldskb->sk);
 
 	if (oldskb->csum_bad || !nft_bridge_iphdr_validate(oldskb))
 		return;
···
 	case htons(ETH_P_IP):
 		switch (priv->type) {
 		case NFT_REJECT_ICMP_UNREACH:
-			nft_reject_br_send_v4_unreach(pkt->skb, pkt->in,
-						      pkt->hook,
+			nft_reject_br_send_v4_unreach(pkt->net, pkt->skb,
+						      pkt->in, pkt->hook,
 						      priv->icmp_code);
 			break;
 		case NFT_REJECT_TCP_RST:
-			nft_reject_br_send_v4_tcp_reset(pkt->skb, pkt->in,
-							pkt->hook);
+			nft_reject_br_send_v4_tcp_reset(pkt->net, pkt->skb,
+							pkt->in, pkt->hook);
 			break;
 		case NFT_REJECT_ICMPX_UNREACH:
-			nft_reject_br_send_v4_unreach(pkt->skb, pkt->in,
-						      pkt->hook,
+			nft_reject_br_send_v4_unreach(pkt->net, pkt->skb,
+						      pkt->in, pkt->hook,
 						      nft_reject_icmp_code(priv->icmp_code));
 			break;
 		}

net/ipv4/netfilter/arp_tables.c

···
 }
 
 /* All zeroes == unconditional rule. */
-static inline bool unconditional(const struct arpt_arp *arp)
+static inline bool unconditional(const struct arpt_entry *e)
 {
 	static const struct arpt_arp uncond;
 
-	return memcmp(arp, &uncond, sizeof(uncond)) == 0;
+	return e->target_offset == sizeof(struct arpt_entry) &&
+	       memcmp(&e->arp, &uncond, sizeof(uncond)) == 0;
 }
 
 /* Figures out from what hook each rule can be called: returns 0 if
···
 				|= ((1 << hook) | (1 << NF_ARP_NUMHOOKS));
 
 			/* Unconditional return/END. */
-			if ((e->target_offset == sizeof(struct arpt_entry) &&
+			if ((unconditional(e) &&
 			     (strcmp(t->target.u.user.name,
 				     XT_STANDARD_TARGET) == 0) &&
-			     t->verdict < 0 && unconditional(&e->arp)) ||
-			    visited) {
+			     t->verdict < 0) || visited) {
 				unsigned int oldpos, size;
 
 				if ((strcmp(t->target.u.user.name,
···
 	return 1;
 }
 
-static inline int check_entry(const struct arpt_entry *e, const char *name)
+static inline int check_entry(const struct arpt_entry *e)
 {
 	const struct xt_entry_target *t;
 
-	if (!arp_checkentry(&e->arp)) {
-		duprintf("arp_tables: arp check failed %p %s.\n", e, name);
+	if (!arp_checkentry(&e->arp))
 		return -EINVAL;
-	}
 
 	if (e->target_offset + sizeof(struct xt_entry_target) > e->next_offset)
 		return -EINVAL;
···
 	struct xt_target *target;
 	int ret;
 
-	ret = check_entry(e, name);
-	if (ret)
-		return ret;
-
 	e->counters.pcnt = xt_percpu_counter_alloc();
 	if (IS_ERR_VALUE(e->counters.pcnt))
 		return -ENOMEM;
···
 	const struct xt_entry_target *t;
 	unsigned int verdict;
 
-	if (!unconditional(&e->arp))
+	if (!unconditional(e))
 		return false;
 	t = arpt_get_target_c(e);
 	if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
···
 					     unsigned int valid_hooks)
 {
 	unsigned int h;
+	int err;
 
 	if ((unsigned long)e % __alignof__(struct arpt_entry) != 0 ||
-	    (unsigned char *)e + sizeof(struct arpt_entry) >= limit) {
+	    (unsigned char *)e + sizeof(struct arpt_entry) >= limit ||
+	    (unsigned char *)e + e->next_offset > limit) {
 		duprintf("Bad offset %p\n", e);
 		return -EINVAL;
 	}
···
 		return -EINVAL;
 	}
 
+	err = check_entry(e);
+	if (err)
+		return err;
+
 	/* Check hooks & underflows */
 	for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
 		if (!(valid_hooks & (1 << h)))
···
 			newinfo->hook_entry[h] = hook_entries[h];
 		if ((unsigned char *)e - base == underflows[h]) {
 			if (!check_underflow(e)) {
-				pr_err("Underflows must be unconditional and "
-				       "use the STANDARD target with "
-				       "ACCEPT/DROP\n");
+				pr_debug("Underflows must be unconditional and "
+					 "use the STANDARD target with "
+					 "ACCEPT/DROP\n");
 				return -EINVAL;
 			}
 			newinfo->underflow[h] = underflows[h];
···
 			 sizeof(struct arpt_get_entries) + get.size);
 		return -EINVAL;
 	}
+	get.name[sizeof(get.name) - 1] = '\0';
 
 	t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
 	if (!IS_ERR_OR_NULL(t)) {
···
 
 	duprintf("check_compat_entry_size_and_hooks %p\n", e);
 	if ((unsigned long)e % __alignof__(struct compat_arpt_entry) != 0 ||
-	    (unsigned char *)e + sizeof(struct compat_arpt_entry) >= limit) {
+	    (unsigned char *)e + sizeof(struct compat_arpt_entry) >= limit ||
+	    (unsigned char *)e + e->next_offset > limit) {
 		duprintf("Bad offset %p, limit = %p\n", e, limit);
 		return -EINVAL;
 	}
···
 	}
 
 	/* For purposes of check_entry casting the compat entry is fine */
-	ret = check_entry((struct arpt_entry *)e, name);
+	ret = check_entry((struct arpt_entry *)e);
 	if (ret)
 		return ret;
 
···
 			 *len, sizeof(get) + get.size);
 		return -EINVAL;
 	}
+	get.name[sizeof(get.name) - 1] = '\0';
 
 	xt_compat_lock(NFPROTO_ARP);
 	t = xt_find_table_lock(net, NFPROTO_ARP, get.name);

net/ipv4/netfilter/ip_tables.c

···
 
 /* All zeroes == unconditional rule. */
 /* Mildly perf critical (only if packet tracing is on) */
-static inline bool unconditional(const struct ipt_ip *ip)
+static inline bool unconditional(const struct ipt_entry *e)
 {
 	static const struct ipt_ip uncond;
 
-	return memcmp(ip, &uncond, sizeof(uncond)) == 0;
+	return e->target_offset == sizeof(struct ipt_entry) &&
+	       memcmp(&e->ip, &uncond, sizeof(uncond)) == 0;
 #undef FWINV
 }
 
···
 	} else if (s == e) {
 		(*rulenum)++;
 
-		if (s->target_offset == sizeof(struct ipt_entry) &&
+		if (unconditional(s) &&
 		    strcmp(t->target.u.kernel.target->name,
 			   XT_STANDARD_TARGET) == 0 &&
-		   t->verdict < 0 &&
-		   unconditional(&s->ip)) {
+		   t->verdict < 0) {
 			/* Tail of chains: STANDARD target (return/policy) */
 			*comment = *chainname == hookname
 				? comments[NF_IP_TRACE_COMMENT_POLICY]
···
 			e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS));
 
 			/* Unconditional return/END. */
-			if ((e->target_offset == sizeof(struct ipt_entry) &&
+			if ((unconditional(e) &&
 			     (strcmp(t->target.u.user.name,
 				     XT_STANDARD_TARGET) == 0) &&
-			     t->verdict < 0 && unconditional(&e->ip)) ||
-			    visited) {
+			     t->verdict < 0) || visited) {
 				unsigned int oldpos, size;
 
 				if ((strcmp(t->target.u.user.name,
···
 }
 
 static int
-check_entry(const struct ipt_entry *e, const char *name)
+check_entry(const struct ipt_entry *e)
 {
 	const struct xt_entry_target *t;
 
-	if (!ip_checkentry(&e->ip)) {
-		duprintf("ip check failed %p %s.\n", e, name);
+	if (!ip_checkentry(&e->ip))
 		return -EINVAL;
-	}
 
 	if (e->target_offset + sizeof(struct xt_entry_target) >
 	    e->next_offset)
···
 	struct xt_mtchk_param mtpar;
 	struct xt_entry_match *ematch;
 
-	ret = check_entry(e, name);
-	if (ret)
-		return ret;
-
 	e->counters.pcnt = xt_percpu_counter_alloc();
 	if (IS_ERR_VALUE(e->counters.pcnt))
 		return -ENOMEM;
···
 	const struct xt_entry_target *t;
 	unsigned int verdict;
 
-	if (!unconditional(&e->ip))
+	if (!unconditional(e))
 		return false;
 	t = ipt_get_target_c(e);
 	if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
···
 			   unsigned int valid_hooks)
 {
 	unsigned int h;
+	int err;
 
 	if ((unsigned long)e % __alignof__(struct ipt_entry) != 0 ||
-	    (unsigned char *)e + sizeof(struct ipt_entry) >= limit) {
+	    (unsigned char *)e + sizeof(struct ipt_entry) >= limit ||
+	    (unsigned char *)e + e->next_offset > limit) {
 		duprintf("Bad offset %p\n", e);
 		return -EINVAL;
 	}
···
 		return -EINVAL;
 	}
 
+	err = check_entry(e);
+	if (err)
+		return err;
+
 	/* Check hooks & underflows */
 	for (h = 0; h < NF_INET_NUMHOOKS; h++) {
 		if (!(valid_hooks & (1 << h)))
···
 			newinfo->hook_entry[h] = hook_entries[h];
 		if ((unsigned char *)e - base == underflows[h]) {
 			if (!check_underflow(e)) {
-				pr_err("Underflows must be unconditional and "
-				       "use the STANDARD target with "
-				       "ACCEPT/DROP\n");
+				pr_debug("Underflows must be unconditional and "
+					 "use the STANDARD target with "
+					 "ACCEPT/DROP\n");
 				return -EINVAL;
 			}
 			newinfo->underflow[h] = underflows[h];
···
 			 *len, sizeof(get) + get.size);
 		return -EINVAL;
 	}
+	get.name[sizeof(get.name) - 1] = '\0';
 
 	t = xt_find_table_lock(net, AF_INET, get.name);
 	if (!IS_ERR_OR_NULL(t)) {
···
 
 	duprintf("check_compat_entry_size_and_hooks %p\n", e);
 	if ((unsigned long)e % __alignof__(struct compat_ipt_entry) != 0 ||
-	    (unsigned char *)e + sizeof(struct compat_ipt_entry) >= limit) {
+	    (unsigned char *)e + sizeof(struct compat_ipt_entry) >= limit ||
+	    (unsigned char *)e + e->next_offset > limit) {
 		duprintf("Bad offset %p, limit = %p\n", e, limit);
 		return -EINVAL;
 	}
···
 	}
 
 	/* For purposes of check_entry casting the compat entry is fine */
-	ret = check_entry((struct ipt_entry *)e, name);
+	ret = check_entry((struct ipt_entry *)e);
 	if (ret)
 		return ret;
 
···
 			 *len, sizeof(get) + get.size);
 		return -EINVAL;
 	}
+	get.name[sizeof(get.name) - 1] = '\0';
 
 	xt_compat_lock(AF_INET);
 	t = xt_find_table_lock(net, AF_INET, get.name);

net/ipv4/netfilter/ipt_SYNPROXY.c

···
 #include <net/netfilter/nf_conntrack_synproxy.h>
 
 static struct iphdr *
-synproxy_build_ip(struct sk_buff *skb, __be32 saddr, __be32 daddr)
+synproxy_build_ip(struct net *net, struct sk_buff *skb, __be32 saddr,
+		  __be32 daddr)
 {
 	struct iphdr *iph;
-	struct net *net = sock_net(skb->sk);
 
 	skb_reset_network_header(skb);
 	iph = (struct iphdr *)skb_put(skb, sizeof(*iph));
···
 }
 
 static void
-synproxy_send_tcp(const struct synproxy_net *snet,
+synproxy_send_tcp(struct net *net,
 		  const struct sk_buff *skb, struct sk_buff *nskb,
 		  struct nf_conntrack *nfct, enum ip_conntrack_info ctinfo,
 		  struct iphdr *niph, struct tcphdr *nth,
 		  unsigned int tcp_hdr_size)
 {
-	struct net *net = nf_ct_net(snet->tmpl);
-
 	nth->check = ~tcp_v4_check(tcp_hdr_size, niph->saddr, niph->daddr, 0);
 	nskb->ip_summed   = CHECKSUM_PARTIAL;
 	nskb->csum_start  = (unsigned char *)nth - nskb->head;
···
 }
 
 static void
-synproxy_send_client_synack(const struct synproxy_net *snet,
+synproxy_send_client_synack(struct net *net,
 			    const struct sk_buff *skb, const struct tcphdr *th,
 			    const struct synproxy_options *opts)
 {
···
 		return;
 	skb_reserve(nskb, MAX_TCP_HEADER);
 
-	niph = synproxy_build_ip(nskb, iph->daddr, iph->saddr);
+	niph = synproxy_build_ip(net, nskb, iph->daddr, iph->saddr);
 
 	skb_reset_transport_header(nskb);
 	nth = (struct tcphdr *)skb_put(nskb, tcp_hdr_size);
···
 
 	synproxy_build_options(nth, opts);
 
-	synproxy_send_tcp(snet, skb, nskb, skb->nfct, IP_CT_ESTABLISHED_REPLY,
+	synproxy_send_tcp(net, skb, nskb, skb->nfct, IP_CT_ESTABLISHED_REPLY,
 			  niph, nth, tcp_hdr_size);
 }
 
 static void
-synproxy_send_server_syn(const struct synproxy_net *snet,
+synproxy_send_server_syn(struct net *net,
 			 const struct sk_buff *skb, const struct tcphdr *th,
 			 const struct synproxy_options *opts, u32 recv_seq)
 {
+	struct synproxy_net *snet = synproxy_pernet(net);
 	struct sk_buff *nskb;
 	struct iphdr *iph, *niph;
 	struct tcphdr *nth;
···
 		return;
 	skb_reserve(nskb, MAX_TCP_HEADER);
 
-	niph = synproxy_build_ip(nskb, iph->saddr, iph->daddr);
+	niph = synproxy_build_ip(net, nskb, iph->saddr, iph->daddr);
 
 	skb_reset_transport_header(nskb);
 	nth = (struct tcphdr *)skb_put(nskb, tcp_hdr_size);
···
 
 	synproxy_build_options(nth, opts);
 
-	synproxy_send_tcp(snet, skb, nskb, &snet->tmpl->ct_general, IP_CT_NEW,
+	synproxy_send_tcp(net, skb, nskb, &snet->tmpl->ct_general, IP_CT_NEW,
 			  niph, nth, tcp_hdr_size);
 }
 
 static void
-synproxy_send_server_ack(const struct synproxy_net *snet,
+synproxy_send_server_ack(struct net *net,
 			 const struct ip_ct_tcp *state,
 			 const struct sk_buff *skb, const struct tcphdr *th,
 			 const struct synproxy_options *opts)
···
 		return;
 	skb_reserve(nskb, MAX_TCP_HEADER);
 
-	niph = synproxy_build_ip(nskb, iph->daddr, iph->saddr);
+	niph = synproxy_build_ip(net, nskb, iph->daddr, iph->saddr);
 
 	skb_reset_transport_header(nskb);
 	nth = (struct tcphdr *)skb_put(nskb, tcp_hdr_size);
···
 
 	synproxy_build_options(nth, opts);
 
-	synproxy_send_tcp(snet, skb, nskb, NULL, 0, niph, nth, tcp_hdr_size);
+	synproxy_send_tcp(net, skb, nskb, NULL, 0, niph, nth, tcp_hdr_size);
 }
 
 static void
-synproxy_send_client_ack(const struct synproxy_net *snet,
+synproxy_send_client_ack(struct net *net,
 			 const struct sk_buff *skb, const struct tcphdr *th,
 			 const struct synproxy_options *opts)
 {
···
 		return;
 	skb_reserve(nskb, MAX_TCP_HEADER);
 
-	niph = synproxy_build_ip(nskb, iph->saddr, iph->daddr);
+	niph = synproxy_build_ip(net, nskb, iph->saddr, iph->daddr);
 
 	skb_reset_transport_header(nskb);
 	nth = (struct tcphdr *)skb_put(nskb, tcp_hdr_size);
···
 
 	synproxy_build_options(nth, opts);
 
-	synproxy_send_tcp(snet, skb, nskb, skb->nfct, IP_CT_ESTABLISHED_REPLY,
+	synproxy_send_tcp(net, skb, nskb, skb->nfct, IP_CT_ESTABLISHED_REPLY,
 			  niph, nth, tcp_hdr_size);
 }
 
 static bool
-synproxy_recv_client_ack(const struct synproxy_net *snet,
+synproxy_recv_client_ack(struct net *net,
 			 const struct sk_buff *skb, const struct tcphdr *th,
 			 struct synproxy_options *opts, u32 recv_seq)
 {
+	struct synproxy_net *snet = synproxy_pernet(net);
 	int mss;
 
 	mss = __cookie_v4_check(ip_hdr(skb), th, ntohl(th->ack_seq) - 1);
···
 	if (opts->options & XT_SYNPROXY_OPT_TIMESTAMP)
 		synproxy_check_timestamp_cookie(opts);
 
-	synproxy_send_server_syn(snet, skb, th, opts, recv_seq);
+	synproxy_send_server_syn(net, skb, th, opts, recv_seq);
 	return true;
 }
 
···
 synproxy_tg4(struct sk_buff *skb, const struct xt_action_param *par)
 {
 	const struct xt_synproxy_info *info = par->targinfo;
-	struct synproxy_net *snet = synproxy_pernet(par->net);
+	struct net *net = par->net;
+	struct synproxy_net *snet = synproxy_pernet(net);
 	struct synproxy_options opts = {};
 	struct tcphdr *th, _th;
 
···
 					  XT_SYNPROXY_OPT_SACK_PERM |
 					  XT_SYNPROXY_OPT_ECN);
 
-		synproxy_send_client_synack(snet, skb, th, &opts);
+		synproxy_send_client_synack(net, skb, th, &opts);
 		return NF_DROP;
 
 	} else if (th->ack && !(th->fin || th->rst || th->syn)) {
 		/* ACK from client */
-		synproxy_recv_client_ack(snet, skb, th, &opts, ntohl(th->seq));
+		synproxy_recv_client_ack(net, skb, th, &opts, ntohl(th->seq));
 		return NF_DROP;
 	}
 
···
 				       struct sk_buff *skb,
 				       const struct nf_hook_state *nhs)
 {
-	struct synproxy_net *snet = synproxy_pernet(nhs->net);
+	struct net *net = nhs->net;
+	struct synproxy_net *snet = synproxy_pernet(net);
 	enum ip_conntrack_info ctinfo;
 	struct nf_conn *ct;
 	struct nf_conn_synproxy *synproxy;
···
 			 * therefore we need to add 1 to make the SYN sequence
 			 * number match the one of first SYN.
 			 */
-			if (synproxy_recv_client_ack(snet, skb, th, &opts,
+			if (synproxy_recv_client_ack(net, skb, th, &opts,
 						     ntohl(th->seq) + 1))
 				this_cpu_inc(snet->stats->cookie_retrans);
 
···
 				  XT_SYNPROXY_OPT_SACK_PERM);
 
 		swap(opts.tsval, opts.tsecr);
-		synproxy_send_server_ack(snet, state, skb, th, &opts);
+		synproxy_send_server_ack(net, state, skb, th, &opts);
 
 		nf_ct_seqadj_init(ct, ctinfo, synproxy->isn - ntohl(th->seq));
 
 		swap(opts.tsval, opts.tsecr);
-		synproxy_send_client_ack(snet, skb, th, &opts);
+		synproxy_send_client_ack(net, skb, th, &opts);
 
 		consume_skb(skb);
 		return NF_STOLEN;

net/ipv6/netfilter/ip6_tables.c

···
 
 /* All zeroes == unconditional rule. */
 /* Mildly perf critical (only if packet tracing is on) */
-static inline bool unconditional(const struct ip6t_ip6 *ipv6)
+static inline bool unconditional(const struct ip6t_entry *e)
 {
 	static const struct ip6t_ip6 uncond;
 
-	return memcmp(ipv6, &uncond, sizeof(uncond)) == 0;
+	return e->target_offset == sizeof(struct ip6t_entry) &&
+	       memcmp(&e->ipv6, &uncond, sizeof(uncond)) == 0;
 }
 
 static inline const struct xt_entry_target *
···
 	} else if (s == e) {
 		(*rulenum)++;
 
-		if (s->target_offset == sizeof(struct ip6t_entry) &&
+		if (unconditional(s) &&
 		    strcmp(t->target.u.kernel.target->name,
 			   XT_STANDARD_TARGET) == 0 &&
-		    t->verdict < 0 &&
-		    unconditional(&s->ipv6)) {
+		    t->verdict < 0) {
 			/* Tail of chains: STANDARD target (return/policy) */
 			*comment = *chainname == hookname
 				? comments[NF_IP6_TRACE_COMMENT_POLICY]
···
 			e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS));
 
 			/* Unconditional return/END. */
-			if ((e->target_offset == sizeof(struct ip6t_entry) &&
+			if ((unconditional(e) &&
 			     (strcmp(t->target.u.user.name,
 				     XT_STANDARD_TARGET) == 0) &&
-			     t->verdict < 0 &&
-			     unconditional(&e->ipv6)) || visited) {
+			     t->verdict < 0) || visited) {
 				unsigned int oldpos, size;
 
 				if ((strcmp(t->target.u.user.name,
···
 }
 
 static int
-check_entry(const struct ip6t_entry *e, const char *name)
+check_entry(const struct ip6t_entry *e)
 {
 	const struct xt_entry_target *t;
 
-	if (!ip6_checkentry(&e->ipv6)) {
-		duprintf("ip_tables: ip check failed %p %s.\n", e, name);
+	if (!ip6_checkentry(&e->ipv6))
 		return -EINVAL;
-	}
 
 	if (e->target_offset + sizeof(struct xt_entry_target) >
 	    e->next_offset)
···
 	struct xt_mtchk_param mtpar;
 	struct xt_entry_match *ematch;
 
-	ret = check_entry(e, name);
-	if (ret)
-		return ret;
-
 	e->counters.pcnt = xt_percpu_counter_alloc();
 	if (IS_ERR_VALUE(e->counters.pcnt))
 		return -ENOMEM;
···
 	const struct xt_entry_target *t;
 	unsigned int verdict;
 
-	if (!unconditional(&e->ipv6))
+	if (!unconditional(e))
 		return false;
 	t = ip6t_get_target_c(e);
 	if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
···
 			   unsigned int valid_hooks)
 {
 	unsigned int h;
+	int err;
 
 	if ((unsigned long)e % __alignof__(struct ip6t_entry) != 0 ||
-	    (unsigned char *)e + sizeof(struct ip6t_entry) >= limit) {
+	    (unsigned char *)e + sizeof(struct ip6t_entry) >= limit ||
+	    (unsigned char *)e + e->next_offset > limit) {
 		duprintf("Bad offset %p\n", e);
 		return -EINVAL;
 	}
···
 		return -EINVAL;
 	}
 
+	err = check_entry(e);
+	if (err)
+		return err;
+
 	/* Check hooks & underflows */
 	for (h = 0; h < NF_INET_NUMHOOKS; h++) {
 		if (!(valid_hooks & (1 << h)))
···
 			newinfo->hook_entry[h] = hook_entries[h];
 		if ((unsigned char *)e - base == underflows[h]) {
 			if (!check_underflow(e)) {
-				pr_err("Underflows must be unconditional and "
-				       "use the STANDARD target with "
-				       "ACCEPT/DROP\n");
+				pr_debug("Underflows must be unconditional and "
+					 "use the STANDARD target with "
+					 "ACCEPT/DROP\n");
 				return -EINVAL;
 			}
 			newinfo->underflow[h] = underflows[h];
···
 			 *len, sizeof(get) + get.size);
 		return -EINVAL;
 	}
+	get.name[sizeof(get.name) - 1] = '\0';
 
 	t = xt_find_table_lock(net, AF_INET6, get.name);
 	if (!IS_ERR_OR_NULL(t)) {
···
 
 	duprintf("check_compat_entry_size_and_hooks %p\n", e);
 	if ((unsigned long)e % __alignof__(struct compat_ip6t_entry) != 0 ||
-	    (unsigned char *)e + sizeof(struct compat_ip6t_entry) >= limit) {
+	    (unsigned char *)e + sizeof(struct compat_ip6t_entry) >= limit ||
+	    (unsigned char *)e + e->next_offset > limit) {
 		duprintf("Bad offset %p, limit = %p\n", e, limit);
 		return -EINVAL;
 	}
···
 	}
 
 	/* For purposes of check_entry casting the compat entry is fine */
-	ret = check_entry((struct ip6t_entry *)e, name);
+	ret = check_entry((struct ip6t_entry *)e);
 	if (ret)
 		return ret;
 
···
 			 *len, sizeof(get) + get.size);
 		return -EINVAL;
 	}
+	get.name[sizeof(get.name) - 1] = '\0';
 
 	xt_compat_lock(AF_INET6);
 	t = xt_find_table_lock(net, AF_INET6, get.name);

net/netfilter/ipset/ip_set_bitmap_gen.h

···
 	if (!nested)
 		goto nla_put_failure;
 	if (mtype_do_head(skb, map) ||
-	    nla_put_net32(skb, IPSET_ATTR_REFERENCES, htonl(set->ref - 1)) ||
+	    nla_put_net32(skb, IPSET_ATTR_REFERENCES, htonl(set->ref)) ||
 	    nla_put_net32(skb, IPSET_ATTR_MEMSIZE, htonl(memsize)))
 		goto nla_put_failure;
 	if (unlikely(ip_set_put_flags(skb, set)))

net/netfilter/ipset/ip_set_core.c

···
 	write_unlock_bh(&ip_set_ref_lock);
 }
 
+/* set->ref can be swapped out by ip_set_swap, netlink events (like dump) need
+ * a separate reference counter
+ */
+static inline void
+__ip_set_get_netlink(struct ip_set *set)
+{
+	write_lock_bh(&ip_set_ref_lock);
+	set->ref_netlink++;
+	write_unlock_bh(&ip_set_ref_lock);
+}
+
+static inline void
+__ip_set_put_netlink(struct ip_set *set)
+{
+	write_lock_bh(&ip_set_ref_lock);
+	BUG_ON(set->ref_netlink == 0);
+	set->ref_netlink--;
+	write_unlock_bh(&ip_set_ref_lock);
+}
+
 /* Add, del and test set entries from kernel.
  *
  * The set behind the index must exist and must be referenced
···
 	if (!attr[IPSET_ATTR_SETNAME]) {
 		for (i = 0; i < inst->ip_set_max; i++) {
 			s = ip_set(inst, i);
-			if (s && s->ref) {
+			if (s && (s->ref || s->ref_netlink)) {
 				ret = -IPSET_ERR_BUSY;
 				goto out;
 			}
···
 		if (!s) {
 			ret = -ENOENT;
 			goto out;
-		} else if (s->ref) {
+		} else if (s->ref || s->ref_netlink) {
 			ret = -IPSET_ERR_BUSY;
 			goto out;
 		}
···
 	      from->family == to->family))
 		return -IPSET_ERR_TYPE_MISMATCH;
 
+	if (from->ref_netlink || to->ref_netlink)
+		return -EBUSY;
+
 	strncpy(from_name, from->name, IPSET_MAXNAMELEN);
 	strncpy(from->name, to->name, IPSET_MAXNAMELEN);
 	strncpy(to->name, from_name, IPSET_MAXNAMELEN);
···
 		if (set->variant->uref)
 			set->variant->uref(set, cb, false);
 		pr_debug("release set %s\n", set->name);
-		__ip_set_put_byindex(inst, index);
+		__ip_set_put_netlink(set);
 	}
 	return 0;
 }
···
 		if (!cb->args[IPSET_CB_ARG0]) {
 			/* Start listing: make sure set won't be destroyed */
 			pr_debug("reference set\n");
-			set->ref++;
+			set->ref_netlink++;
 		}
 		write_unlock_bh(&ip_set_ref_lock);
 		nlh = start_msg(skb, NETLINK_CB(cb->skb).portid,
···
 		if (set->variant->uref)
 			set->variant->uref(set, cb, false);
 		pr_debug("release set %s\n", set->name);
-		__ip_set_put_byindex(inst, index);
+		__ip_set_put_netlink(set);
 		cb->args[IPSET_CB_ARG0] = 0;
 	}
 out:

net/netfilter/ipset/ip_set_hash_gen.h

···
 	if (nla_put_u32(skb, IPSET_ATTR_MARKMASK, h->markmask))
 		goto nla_put_failure;
 #endif
-	if (nla_put_net32(skb, IPSET_ATTR_REFERENCES, htonl(set->ref - 1)) ||
+	if (nla_put_net32(skb, IPSET_ATTR_REFERENCES, htonl(set->ref)) ||
 	    nla_put_net32(skb, IPSET_ATTR_MEMSIZE, htonl(memsize)))
 		goto nla_put_failure;
 	if (unlikely(ip_set_put_flags(skb, set)))

net/netfilter/ipset/ip_set_list_set.c

···
 	if (!nested)
 		goto nla_put_failure;
 	if (nla_put_net32(skb, IPSET_ATTR_SIZE, htonl(map->size)) ||
-	    nla_put_net32(skb, IPSET_ATTR_REFERENCES, htonl(set->ref - 1)) ||
+	    nla_put_net32(skb, IPSET_ATTR_REFERENCES, htonl(set->ref)) ||
 	    nla_put_net32(skb, IPSET_ATTR_MEMSIZE,
 			  htonl(sizeof(*map) + n * set->dsize)))
 		goto nla_put_failure;

net/netfilter/nfnetlink_queue.c

···
 	/* nfnetlink_unicast will either free the nskb or add it to a socket */
 	err = nfnetlink_unicast(nskb, net, queue->peer_portid, MSG_DONTWAIT);
 	if (err < 0) {
-		queue->queue_user_dropped++;
+		if (queue->flags & NFQA_CFG_F_FAIL_OPEN) {
+			failopen = 1;
+			err = 0;
+		} else {
+			queue->queue_user_dropped++;
+		}
 		goto err_out_unlock;
 	}
 

net/openvswitch/Kconfig

···
 	depends on INET
 	depends on !NF_CONNTRACK || \
 		   (NF_CONNTRACK && ((!NF_DEFRAG_IPV6 || NF_DEFRAG_IPV6) && \
-				     (!NF_NAT || NF_NAT)))
+				     (!NF_NAT || NF_NAT) && \
+				     (!NF_NAT_IPV4 || NF_NAT_IPV4) && \
+				     (!NF_NAT_IPV6 || NF_NAT_IPV6)))
 	select LIBCRC32C
 	select MPLS
 	select NET_MPLS_GSO

net/openvswitch/conntrack.c

···
 	switch (ctinfo) {
 	case IP_CT_RELATED:
 	case IP_CT_RELATED_REPLY:
-		if (skb->protocol == htons(ETH_P_IP) &&
+		if (IS_ENABLED(CONFIG_NF_NAT_IPV4) &&
+		    skb->protocol == htons(ETH_P_IP) &&
 		    ip_hdr(skb)->protocol == IPPROTO_ICMP) {
 			if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo,
 							   hooknum))
 				err = NF_DROP;
 			goto push;
-#if IS_ENABLED(CONFIG_NF_NAT_IPV6)
-		} else if (skb->protocol == htons(ETH_P_IPV6)) {
+		} else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) &&
+			   skb->protocol == htons(ETH_P_IPV6)) {
 			__be16 frag_off;
 			u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 			int hdrlen = ipv6_skip_exthdr(skb,
···
 					err = NF_DROP;
 				goto push;
 			}
-#endif
 		}
 		/* Non-ICMP, fall thru to initialize if needed. */
 	case IP_CT_NEW:
···
 
 	/* Determine NAT type.
 	 * Check if the NAT type can be deduced from the tracked connection.
-	 * Make sure expected traffic is NATted only when committing.
+	 * Make sure new expected connections (IP_CT_RELATED) are NATted only
+	 * when committing.
 	 */
 	if (info->nat & OVS_CT_NAT && ctinfo != IP_CT_NEW &&
 	    ct->status & IPS_NAT_MASK &&
-	    (!(ct->status & IPS_EXPECTED_BIT) || info->commit)) {
+	    (ctinfo != IP_CT_RELATED || info->commit)) {
 		/* NAT an established or related connection like before. */
 		if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY)
 			/* This is the REPLY direction for a connection
···
 	}
 
 	if (info->range.flags & NF_NAT_RANGE_MAP_IPS) {
-		if (info->family == NFPROTO_IPV4) {
+		if (IS_ENABLED(CONFIG_NF_NAT_IPV4) &&
+		    info->family == NFPROTO_IPV4) {
 			if (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MIN,
 					    info->range.min_addr.ip) ||
 			    (info->range.max_addr.ip
···
 			     (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MAX,
 					      info->range.max_addr.ip))))
 				return false;
-#if IS_ENABLED(CONFIG_NF_NAT_IPV6)
-		} else if (info->family == NFPROTO_IPV6) {
+		} else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) &&
+			   info->family == NFPROTO_IPV6) {
 			if (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MIN,
 					     &info->range.min_addr.in6) ||
 			    (memcmp(&info->range.max_addr.in6,
···
 			     (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MAX,
 					       &info->range.max_addr.in6))))
 				return false;
-#endif
 		} else {
 			return false;
 		}