[NETFILTER]: Change {ip,ip6,arp}_tables to use centralized error checking

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 50 insertions, 13 deletions

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 7d7ab94a7a2e..2fdf75da7a70 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -480,6 +480,11 @@ static inline int check_entry(struct arpt_entry *e, const char *name, unsigned i
         }
         t->u.kernel.target = target;
 
+        ret = xt_check_target(target, NF_ARP, t->u.target_size - sizeof(*t),
+                              name, e->comefrom, 0, 0);
+        if (ret)
+                goto err;
+
         if (t->u.kernel.target == &arpt_standard_target) {
                 if (!standard_check(t, size)) {
                         ret = -EINVAL;
@@ -490,16 +495,16 @@ static inline int check_entry(struct arpt_entry *e, const char *name, unsigned i
                                                       t->u.target_size
                                                       - sizeof(*t),
                                                       e->comefrom)) {
-                module_put(t->u.kernel.target->me);
                 duprintf("arp_tables: check failed for `%s'.\n",
                          t->u.kernel.target->name);
                 ret = -EINVAL;
-                goto out;
+                goto err;
         }
 
         (*i)++;
         return 0;
-
+err:
+        module_put(t->u.kernel.target->me);
 out:
         return ret;
 }
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 16f47c675fef..f884ca223295 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -508,6 +508,7 @@ check_match(struct ipt_entry_match *m,
             unsigned int *i)
 {
         struct ipt_match *match;
+        int ret;
 
         match = try_then_request_module(xt_find_match(AF_INET, m->u.user.name,
                                                    m->u.user.revision),
@@ -518,18 +519,27 @@ check_match(struct ipt_entry_match *m,
         }
         m->u.kernel.match = match;
 
+        ret = xt_check_match(match, AF_INET, m->u.match_size - sizeof(*m),
+                             name, hookmask, ip->proto,
+                             ip->invflags & IPT_INV_PROTO);
+        if (ret)
+                goto err;
+
         if (m->u.kernel.match->checkentry
             && !m->u.kernel.match->checkentry(name, ip, m->data,
                                               m->u.match_size - sizeof(*m),
                                               hookmask)) {
-                module_put(m->u.kernel.match->me);
                 duprintf("ip_tables: check failed for `%s'.\n",
                          m->u.kernel.match->name);
-                return -EINVAL;
+                ret = -EINVAL;
+                goto err;
         }
 
         (*i)++;
         return 0;
+err:
+        module_put(m->u.kernel.match->me);
+        return ret;
 }
 
 static struct ipt_target ipt_standard_target;
@@ -565,6 +575,12 @@ check_entry(struct ipt_entry *e, const char *name, unsigned int size,
         }
         t->u.kernel.target = target;
 
+        ret = xt_check_target(target, AF_INET, t->u.target_size - sizeof(*t),
+                              name, e->comefrom, e->ip.proto,
+                              e->ip.invflags & IPT_INV_PROTO);
+        if (ret)
+                goto err;
+
         if (t->u.kernel.target == &ipt_standard_target) {
                 if (!standard_check(t, size)) {
                         ret = -EINVAL;
@@ -575,16 +591,16 @@ check_entry(struct ipt_entry *e, const char *name, unsigned int size,
                                                       t->u.target_size
                                                       - sizeof(*t),
                                                       e->comefrom)) {
-                module_put(t->u.kernel.target->me);
                 duprintf("ip_tables: check failed for `%s'.\n",
                          t->u.kernel.target->name);
                 ret = -EINVAL;
-                goto cleanup_matches;
+                goto err;
         }
 
         (*i)++;
         return 0;
-
+ err:
+        module_put(t->u.kernel.target->me);
  cleanup_matches:
         IPT_MATCH_ITERATE(e, cleanup_match, &j);
         return ret;
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index 74ff56c322f4..1cd70683f2e2 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -575,6 +575,7 @@ check_match(struct ip6t_entry_match *m,
             unsigned int *i)
 {
         struct ip6t_match *match;
+        int ret;
 
         match = try_then_request_module(xt_find_match(AF_INET6, m->u.user.name,
                                         m->u.user.revision),
@@ -585,18 +586,27 @@ check_match(struct ip6t_entry_match *m,
         }
         m->u.kernel.match = match;
 
+        ret = xt_check_match(match, AF_INET6, m->u.match_size - sizeof(*m),
+                             name, hookmask, ipv6->proto,
+                             ipv6->invflags & IP6T_INV_PROTO);
+        if (ret)
+                goto err;
+
         if (m->u.kernel.match->checkentry
             && !m->u.kernel.match->checkentry(name, ipv6, m->data,
                                               m->u.match_size - sizeof(*m),
                                               hookmask)) {
-                module_put(m->u.kernel.match->me);
                 duprintf("ip_tables: check failed for `%s'.\n",
                          m->u.kernel.match->name);
-                return -EINVAL;
+                ret = -EINVAL;
+                goto err;
         }
 
         (*i)++;
         return 0;
+err:
+        module_put(m->u.kernel.match->me);
+        return ret;
 }
 
 static struct ip6t_target ip6t_standard_target;
@@ -632,6 +642,12 @@ check_entry(struct ip6t_entry *e, const char *name, unsigned int size,
         }
         t->u.kernel.target = target;
 
+        ret = xt_check_target(target, AF_INET6, t->u.target_size - sizeof(*t),
+                              name, e->comefrom, e->ipv6.proto,
+                              e->ipv6.invflags & IP6T_INV_PROTO);
+        if (ret)
+                goto err;
+
         if (t->u.kernel.target == &ip6t_standard_target) {
                 if (!standard_check(t, size)) {
                         ret = -EINVAL;
@@ -642,16 +658,16 @@ check_entry(struct ip6t_entry *e, const char *name, unsigned int size,
                                                       t->u.target_size
                                                       - sizeof(*t),
                                                       e->comefrom)) {
-                module_put(t->u.kernel.target->me);
                 duprintf("ip_tables: check failed for `%s'.\n",
                          t->u.kernel.target->name);
                 ret = -EINVAL;
-                goto cleanup_matches;
+                goto err;
         }
 
         (*i)++;
         return 0;
-
+ err:
+        module_put(t->u.kernel.target->me);
  cleanup_matches:
         IP6T_MATCH_ITERATE(e, cleanup_match, &j);
         return ret;