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

Pablo Neira Ayuso says:

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

The following patchset contain Netfilter fixes for your net tree, they are:

1) Fix a race in nfnetlink_log and nfnetlink_queue that can lead to a crash.
   This problem is due to wrong order in the per-net registration and netlink
   socket events. Patch from Francesco Ruggeri.

2) Make sure that counters that userspace pass us are higher than 0 in all the
   x_tables frontends. Discovered via Trinity, patch from Dave Jones.

3) Revert a patch for br_netfilter to rely on the conntrack status bits. This
   breaks stateless IPv6 NAT transformations. Patch from Florian Westphal.
====================

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

include/linux/skbuff.h

@@ -176,6 +176,7 @@ struct nf_bridge_info {
 	struct net_device	*physindev;
 	struct net_device	*physoutdev;
 	char			neigh_header[8];
+	__be32			ipv4_daddr;
 };
 #endif
 

net/bridge/br_netfilter.c

@@ -37,10 +37,6 @@
 #include <net/route.h>
 #include <net/netfilter/br_netfilter.h>
 
-#if IS_ENABLED(CONFIG_NF_CONNTRACK)
-#include <net/netfilter/nf_conntrack.h>
-#endif
-
 #include <asm/uaccess.h>
 #include "br_private.h"
 #ifdef CONFIG_SYSCTL
@@ -350,24 +346,15 @@ free_skb:
 	return 0;
 }
 
-static bool dnat_took_place(const struct sk_buff *skb)
+static bool daddr_was_changed(const struct sk_buff *skb,
+			      const struct nf_bridge_info *nf_bridge)
 {
-#if IS_ENABLED(CONFIG_NF_CONNTRACK)
-	enum ip_conntrack_info ctinfo;
-	struct nf_conn *ct;
-
-	ct = nf_ct_get(skb, &ctinfo);
-	if (!ct || nf_ct_is_untracked(ct))
-		return false;
-
-	return test_bit(IPS_DST_NAT_BIT, &ct->status);
-#else
-	return false;
-#endif
+	return ip_hdr(skb)->daddr != nf_bridge->ipv4_daddr;
 }
 
 /* This requires some explaining. If DNAT has taken place,
  * we will need to fix up the destination Ethernet address.
+ * This is also true when SNAT takes place (for the reply direction).
  *
  * There are two cases to consider:
  * 1. The packet was DNAT'ed to a device in the same bridge
@@ -421,7 +408,7 @@ static int br_nf_pre_routing_finish(struct sock *sk, struct sk_buff *skb)
 		nf_bridge->pkt_otherhost = false;
 	}
 	nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING;
-	if (dnat_took_place(skb)) {
+	if (daddr_was_changed(skb, nf_bridge)) {
 		if ((err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev))) {
 			struct in_device *in_dev = __in_dev_get_rcu(dev);
 
@@ -632,6 +619,7 @@ static unsigned int br_nf_pre_routing(const struct nf_hook_ops *ops,
 				      struct sk_buff *skb,
 				      const struct nf_hook_state *state)
 {
+	struct nf_bridge_info *nf_bridge;
 	struct net_bridge_port *p;
 	struct net_bridge *br;
 	__u32 len = nf_bridge_encap_header_len(skb);
@@ -669,6 +657,9 @@ static unsigned int br_nf_pre_routing(const struct nf_hook_ops *ops,
 	if (!setup_pre_routing(skb))
 		return NF_DROP;
 
+	nf_bridge = nf_bridge_info_get(skb);
+	nf_bridge->ipv4_daddr = ip_hdr(skb)->daddr;
+
 	skb->protocol = htons(ETH_P_IP);
 
 	NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, state->sk, skb,

net/bridge/netfilter/ebtables.c

@@ -1117,6 +1117,8 @@ static int do_replace(struct net *net, const void __user *user,
 		return -ENOMEM;
 	if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
 		return -ENOMEM;
+	if (tmp.num_counters == 0)
+		return -EINVAL;
 
 	tmp.name[sizeof(tmp.name) - 1] = 0;
 
@@ -2159,6 +2161,8 @@ static int compat_copy_ebt_replace_from_user(struct ebt_replace *repl,
 		return -ENOMEM;
 	if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
 		return -ENOMEM;
+	if (tmp.num_counters == 0)
+		return -EINVAL;
 
 	memcpy(repl, &tmp, offsetof(struct ebt_replace, hook_entry));
 

net/ipv4/netfilter/arp_tables.c

@@ -1075,6 +1075,9 @@ static int do_replace(struct net *net, const void __user *user,
 	/* overflow check */
 	if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
 		return -ENOMEM;
+	if (tmp.num_counters == 0)
+		return -EINVAL;
+
 	tmp.name[sizeof(tmp.name)-1] = 0;
 
 	newinfo = xt_alloc_table_info(tmp.size);
@@ -1499,6 +1502,9 @@ static int compat_do_replace(struct net *net, void __user *user,
 		return -ENOMEM;
 	if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
 		return -ENOMEM;
+	if (tmp.num_counters == 0)
+		return -EINVAL;
+
 	tmp.name[sizeof(tmp.name)-1] = 0;
 
 	newinfo = xt_alloc_table_info(tmp.size);

net/ipv4/netfilter/ip_tables.c

@@ -1262,6 +1262,9 @@ do_replace(struct net *net, const void __user *user, unsigned int len)
 	/* overflow check */
 	if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
 		return -ENOMEM;
+	if (tmp.num_counters == 0)
+		return -EINVAL;
+
 	tmp.name[sizeof(tmp.name)-1] = 0;
 
 	newinfo = xt_alloc_table_info(tmp.size);
@@ -1809,6 +1812,9 @@ compat_do_replace(struct net *net, void __user *user, unsigned int len)
 		return -ENOMEM;
 	if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
 		return -ENOMEM;
+	if (tmp.num_counters == 0)
+		return -EINVAL;
+
 	tmp.name[sizeof(tmp.name)-1] = 0;
 
 	newinfo = xt_alloc_table_info(tmp.size);

net/ipv6/netfilter/ip6_tables.c

@@ -1275,6 +1275,9 @@ do_replace(struct net *net, const void __user *user, unsigned int len)
 	/* overflow check */
 	if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
 		return -ENOMEM;
+	if (tmp.num_counters == 0)
+		return -EINVAL;
+
 	tmp.name[sizeof(tmp.name)-1] = 0;
 
 	newinfo = xt_alloc_table_info(tmp.size);
@@ -1822,6 +1825,9 @@ compat_do_replace(struct net *net, void __user *user, unsigned int len)
 		return -ENOMEM;
 	if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
 		return -ENOMEM;
+	if (tmp.num_counters == 0)
+		return -EINVAL;
+
 	tmp.name[sizeof(tmp.name)-1] = 0;
 
 	newinfo = xt_alloc_table_info(tmp.size);

net/netfilter/nfnetlink_log.c

@@ -1073,7 +1073,13 @@ static struct pernet_operations nfnl_log_net_ops = {
 
 static int __init nfnetlink_log_init(void)
 {
-	int status = -ENOMEM;
+	int status;
+
+	status = register_pernet_subsys(&nfnl_log_net_ops);
+	if (status < 0) {
+		pr_err("failed to register pernet ops\n");
+		goto out;
+	}
 
 	netlink_register_notifier(&nfulnl_rtnl_notifier);
 	status = nfnetlink_subsys_register(&nfulnl_subsys);
@@ -1088,28 +1094,23 @@ static int __init nfnetlink_log_init(void)
 		goto cleanup_subsys;
 	}
 
-	status = register_pernet_subsys(&nfnl_log_net_ops);
-	if (status < 0) {
-		pr_err("failed to register pernet ops\n");
-		goto cleanup_logger;
-	}
 	return status;
 
-cleanup_logger:
-	nf_log_unregister(&nfulnl_logger);
 cleanup_subsys:
 	nfnetlink_subsys_unregister(&nfulnl_subsys);
 cleanup_netlink_notifier:
 	netlink_unregister_notifier(&nfulnl_rtnl_notifier);
+	unregister_pernet_subsys(&nfnl_log_net_ops);
+out:
 	return status;
 }
 
 static void __exit nfnetlink_log_fini(void)
 {
-	unregister_pernet_subsys(&nfnl_log_net_ops);
 	nf_log_unregister(&nfulnl_logger);
 	nfnetlink_subsys_unregister(&nfulnl_subsys);
 	netlink_unregister_notifier(&nfulnl_rtnl_notifier);
+	unregister_pernet_subsys(&nfnl_log_net_ops);
 }
 
 MODULE_DESCRIPTION("netfilter userspace logging");

net/netfilter/nfnetlink_queue_core.c

@@ -1317,7 +1317,13 @@ static struct pernet_operations nfnl_queue_net_ops = {
 
 static int __init nfnetlink_queue_init(void)
 {
-	int status = -ENOMEM;
+	int status;
+
+	status = register_pernet_subsys(&nfnl_queue_net_ops);
+	if (status < 0) {
+		pr_err("nf_queue: failed to register pernet ops\n");
+		goto out;
+	}
 
 	netlink_register_notifier(&nfqnl_rtnl_notifier);
 	status = nfnetlink_subsys_register(&nfqnl_subsys);
@@ -1326,19 +1332,13 @@ static int __init nfnetlink_queue_init(void)
 		goto cleanup_netlink_notifier;
 	}
 
-	status = register_pernet_subsys(&nfnl_queue_net_ops);
-	if (status < 0) {
-		pr_err("nf_queue: failed to register pernet ops\n");
-		goto cleanup_subsys;
-	}
 	register_netdevice_notifier(&nfqnl_dev_notifier);
 	nf_register_queue_handler(&nfqh);
 	return status;
 
-cleanup_subsys:
-	nfnetlink_subsys_unregister(&nfqnl_subsys);
 cleanup_netlink_notifier:
 	netlink_unregister_notifier(&nfqnl_rtnl_notifier);
+out:
 	return status;
 }
 
@@ -1346,9 +1346,9 @@ static void __exit nfnetlink_queue_fini(void)
 {
 	nf_unregister_queue_handler();
 	unregister_netdevice_notifier(&nfqnl_dev_notifier);
-	unregister_pernet_subsys(&nfnl_queue_net_ops);
 	nfnetlink_subsys_unregister(&nfqnl_subsys);
 	netlink_unregister_notifier(&nfqnl_rtnl_notifier);
+	unregister_pernet_subsys(&nfnl_queue_net_ops);
 
 	rcu_barrier(); /* Wait for completion of call_rcu()'s */
 }