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>

7 files changed, 50 insertions, 36 deletions

diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c
index ab55e2472beb..60ddfbeb47f5 100644
--- a/net/bridge/br_netfilter.c
+++ b/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,
diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index 91180a7fc943..24c7c96bf5f8 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/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));
 
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 13bfe84bf3ca..a61200754f4b 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/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);
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index c69db7fa25ee..2d0e265fef6e 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/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);
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index 1a732a1d3c8e..62f5b0d0bc9b 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/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);
diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c
index 3ad91266c821..4ef1fae8445e 100644
--- a/net/netfilter/nfnetlink_log.c
+++ b/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");
diff --git a/net/netfilter/nfnetlink_queue_core.c b/net/netfilter/nfnetlink_queue_core.c
index 0b98c7420239..11c7682fa0ea 100644
--- a/net/netfilter/nfnetlink_queue_core.c
+++ b/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 */
 }