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 your net tree,
they are:

1) Fix missing MODULE_LICENSE() in the new nf_reject_ipv{4,6} modules.

2) Restrict nat and masq expressions to the nat chain type. Otherwise,
   users may crash their kernel if they attach a nat/masq rule to a non
   nat chain.

3) Fix hook validation in nft_compat when non-base chains are used.
   Basically, initialize hook_mask to zero.

4) Make sure you use match/targets in nft_compat from the right chain
   type. The existing validation relies on the table name which can be
   avoided by

5) Better netlink attribute validation in nft_nat. This expression has
   to reject the configuration when no address and proto configurations
   are specified.

6) Interpret NFTA_NAT_REG_*_MAX if only if NFTA_NAT_REG_*_MIN is set.
   Yet another sanity check to reject incorrect configurations from
   userspace.

7) Conditional NAT attribute dumping depending on the existing
   configuration.
====================

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

8 files changed, 159 insertions, 41 deletions

diff --git a/net/ipv4/netfilter/nf_reject_ipv4.c b/net/ipv4/netfilter/nf_reject_ipv4.c
index b023b4eb1a96..92b303dbd5fc 100644
--- a/net/ipv4/netfilter/nf_reject_ipv4.c
+++ b/net/ipv4/netfilter/nf_reject_ipv4.c
@@ -6,6 +6,7 @@
  * published by the Free Software Foundation.
  */
 
+#include <linux/module.h>
 #include <net/ip.h>
 #include <net/tcp.h>
 #include <net/route.h>
@@ -125,3 +126,5 @@ void nf_send_reset(struct sk_buff *oldskb, int hook)
         kfree_skb(nskb);
 }
 EXPORT_SYMBOL_GPL(nf_send_reset);
+
+MODULE_LICENSE("GPL");
diff --git a/net/ipv4/netfilter/nft_masq_ipv4.c b/net/ipv4/netfilter/nft_masq_ipv4.c
index 1c636d6b5b50..c1023c445920 100644
--- a/net/ipv4/netfilter/nft_masq_ipv4.c
+++ b/net/ipv4/netfilter/nft_masq_ipv4.c
@@ -39,6 +39,7 @@ static const struct nft_expr_ops nft_masq_ipv4_ops = {
         .eval           = nft_masq_ipv4_eval,
         .init           = nft_masq_init,
         .dump           = nft_masq_dump,
+        .validate       = nft_masq_validate,
 };
 
 static struct nft_expr_type nft_masq_ipv4_type __read_mostly = {
diff --git a/net/ipv6/netfilter/nf_reject_ipv6.c b/net/ipv6/netfilter/nf_reject_ipv6.c
index 5f5f0438d74d..20d9defc6c59 100644
--- a/net/ipv6/netfilter/nf_reject_ipv6.c
+++ b/net/ipv6/netfilter/nf_reject_ipv6.c
@@ -5,6 +5,8 @@
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */
+
+#include <linux/module.h>
 #include <net/ipv6.h>
 #include <net/ip6_route.h>
 #include <net/ip6_fib.h>
@@ -161,3 +163,5 @@ void nf_send_reset6(struct net *net, struct sk_buff *oldskb, int hook)
                 ip6_local_out(nskb);
 }
 EXPORT_SYMBOL_GPL(nf_send_reset6);
+
+MODULE_LICENSE("GPL");
diff --git a/net/ipv6/netfilter/nft_masq_ipv6.c b/net/ipv6/netfilter/nft_masq_ipv6.c
index 556262f40761..8a7ac685076d 100644
--- a/net/ipv6/netfilter/nft_masq_ipv6.c
+++ b/net/ipv6/netfilter/nft_masq_ipv6.c
@@ -39,6 +39,7 @@ static const struct nft_expr_ops nft_masq_ipv6_ops = {
         .eval           = nft_masq_ipv6_eval,
         .init           = nft_masq_init,
         .dump           = nft_masq_dump,
+        .validate       = nft_masq_validate,
 };
 
 static struct nft_expr_type nft_masq_ipv6_type __read_mostly = {
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 556a0dfa4abc..65eb2a1160d5 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3744,6 +3744,20 @@ static const struct nfnetlink_subsystem nf_tables_subsys = {
         .abort          = nf_tables_abort,
 };
 
+int nft_chain_validate_dependency(const struct nft_chain *chain,
+                                  enum nft_chain_type type)
+{
+        const struct nft_base_chain *basechain;
+
+        if (chain->flags & NFT_BASE_CHAIN) {
+                basechain = nft_base_chain(chain);
+                if (basechain->type->type != type)
+                        return -EOPNOTSUPP;
+        }
+        return 0;
+}
+EXPORT_SYMBOL_GPL(nft_chain_validate_dependency);
+
 /*
  * Loop detection - walk through the ruleset beginning at the destination chain
  * of a new jump until either the source chain is reached (loop) or all
diff --git a/net/netfilter/nft_compat.c b/net/netfilter/nft_compat.c
index 7e2683c8a44a..0480f57a4eb6 100644
--- a/net/netfilter/nft_compat.c
+++ b/net/netfilter/nft_compat.c
@@ -19,9 +19,52 @@
 #include <linux/netfilter/x_tables.h>
 #include <linux/netfilter_ipv4/ip_tables.h>
 #include <linux/netfilter_ipv6/ip6_tables.h>
-#include <asm/uaccess.h> /* for set_fs */
 #include <net/netfilter/nf_tables.h>
 
+static const struct {
+       const char       *name;
+       u8               type;
+} table_to_chaintype[] = {
+       { "filter",     NFT_CHAIN_T_DEFAULT },
+       { "raw",        NFT_CHAIN_T_DEFAULT },
+       { "security",   NFT_CHAIN_T_DEFAULT },
+       { "mangle",     NFT_CHAIN_T_ROUTE },
+       { "nat",        NFT_CHAIN_T_NAT },
+       { },
+};
+
+static int nft_compat_table_to_chaintype(const char *table)
+{
+        int i;
+
+        for (i = 0; table_to_chaintype[i].name != NULL; i++) {
+                if (strcmp(table_to_chaintype[i].name, table) == 0)
+                        return table_to_chaintype[i].type;
+        }
+
+        return -1;
+}
+
+static int nft_compat_chain_validate_dependency(const char *tablename,
+                                                const struct nft_chain *chain)
+{
+        enum nft_chain_type type;
+        const struct nft_base_chain *basechain;
+
+        if (!tablename || !(chain->flags & NFT_BASE_CHAIN))
+                return 0;
+
+        type = nft_compat_table_to_chaintype(tablename);
+        if (type < 0)
+                return -EINVAL;
+
+        basechain = nft_base_chain(chain);
+        if (basechain->type->type != type)
+                return -EINVAL;
+
+        return 0;
+}
+
 union nft_entry {
         struct ipt_entry e4;
         struct ip6t_entry e6;
@@ -95,6 +138,8 @@ nft_target_set_tgchk_param(struct xt_tgchk_param *par,
                 const struct nf_hook_ops *ops = &basechain->ops[0];
 
                 par->hook_mask = 1 << ops->hooknum;
+        } else {
+                par->hook_mask = 0;
         }
         par->family     = ctx->afi->family;
 }
@@ -151,6 +196,10 @@ nft_target_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
         union nft_entry e = {};
         int ret;
 
+        ret = nft_compat_chain_validate_dependency(target->table, ctx->chain);
+        if (ret < 0)
+                goto err;
+
         target_compat_from_user(target, nla_data(tb[NFTA_TARGET_INFO]), info);
 
         if (ctx->nla[NFTA_RULE_COMPAT]) {
@@ -216,6 +265,7 @@ static int nft_target_validate(const struct nft_ctx *ctx,
 {
         struct xt_target *target = expr->ops->data;
         unsigned int hook_mask = 0;
+        int ret;
 
         if (ctx->chain->flags & NFT_BASE_CHAIN) {
                 const struct nft_base_chain *basechain =
@@ -223,11 +273,13 @@ static int nft_target_validate(const struct nft_ctx *ctx,
                 const struct nf_hook_ops *ops = &basechain->ops[0];
 
                 hook_mask = 1 << ops->hooknum;
-                if (hook_mask & target->hooks)
-                        return 0;
+                if (!(hook_mask & target->hooks))
+                        return -EINVAL;
 
-                /* This target is being called from an invalid chain */
-                return -EINVAL;
+                ret = nft_compat_chain_validate_dependency(target->table,
+                                                           ctx->chain);
+                if (ret < 0)
+                        return ret;
         }
         return 0;
 }
@@ -293,6 +345,8 @@ nft_match_set_mtchk_param(struct xt_mtchk_param *par, const struct nft_ctx *ctx,
                 const struct nf_hook_ops *ops = &basechain->ops[0];
 
                 par->hook_mask = 1 << ops->hooknum;
+        } else {
+                par->hook_mask = 0;
         }
         par->family     = ctx->afi->family;
 }
@@ -320,6 +374,10 @@ nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
         union nft_entry e = {};
         int ret;
 
+        ret = nft_compat_chain_validate_dependency(match->name, ctx->chain);
+        if (ret < 0)
+                goto err;
+
         match_compat_from_user(match, nla_data(tb[NFTA_MATCH_INFO]), info);
 
         if (ctx->nla[NFTA_RULE_COMPAT]) {
@@ -379,6 +437,7 @@ static int nft_match_validate(const struct nft_ctx *ctx,
 {
         struct xt_match *match = expr->ops->data;
         unsigned int hook_mask = 0;
+        int ret;
 
         if (ctx->chain->flags & NFT_BASE_CHAIN) {
                 const struct nft_base_chain *basechain =
@@ -386,11 +445,13 @@ static int nft_match_validate(const struct nft_ctx *ctx,
                 const struct nf_hook_ops *ops = &basechain->ops[0];
 
                 hook_mask = 1 << ops->hooknum;
-                if (hook_mask & match->hooks)
-                        return 0;
+                if (!(hook_mask & match->hooks))
+                        return -EINVAL;
 
-                /* This match is being called from an invalid chain */
-                return -EINVAL;
+                ret = nft_compat_chain_validate_dependency(match->name,
+                                                           ctx->chain);
+                if (ret < 0)
+                        return ret;
         }
         return 0;
 }
diff --git a/net/netfilter/nft_masq.c b/net/netfilter/nft_masq.c
index 6637bab00567..d1ffd5eb3a9b 100644
--- a/net/netfilter/nft_masq.c
+++ b/net/netfilter/nft_masq.c
@@ -26,6 +26,11 @@ int nft_masq_init(const struct nft_ctx *ctx,
                   const struct nlattr * const tb[])
 {
         struct nft_masq *priv = nft_expr_priv(expr);
+        int err;
+
+        err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
+        if (err < 0)
+                return err;
 
         if (tb[NFTA_MASQ_FLAGS] == NULL)
                 return 0;
@@ -55,5 +60,12 @@ nla_put_failure:
 }
 EXPORT_SYMBOL_GPL(nft_masq_dump);
 
+int nft_masq_validate(const struct nft_ctx *ctx, const struct nft_expr *expr,
+                      const struct nft_data **data)
+{
+        return nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
+}
+EXPORT_SYMBOL_GPL(nft_masq_validate);
+
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>");
diff --git a/net/netfilter/nft_nat.c b/net/netfilter/nft_nat.c
index 799550b476fb..afe2b0b45ec4 100644
--- a/net/netfilter/nft_nat.c
+++ b/net/netfilter/nft_nat.c
@@ -95,7 +95,13 @@ static int nft_nat_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
         u32 family;
         int err;
 
-        if (tb[NFTA_NAT_TYPE] == NULL)
+        err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
+        if (err < 0)
+                return err;
+
+        if (tb[NFTA_NAT_TYPE] == NULL ||
+            (tb[NFTA_NAT_REG_ADDR_MIN] == NULL &&
+             tb[NFTA_NAT_REG_PROTO_MIN] == NULL))
                 return -EINVAL;
 
         switch (ntohl(nla_get_be32(tb[NFTA_NAT_TYPE]))) {
@@ -120,38 +126,44 @@ static int nft_nat_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
         priv->family = family;
 
         if (tb[NFTA_NAT_REG_ADDR_MIN]) {
-                priv->sreg_addr_min = ntohl(nla_get_be32(
-                                                tb[NFTA_NAT_REG_ADDR_MIN]));
+                priv->sreg_addr_min =
+                        ntohl(nla_get_be32(tb[NFTA_NAT_REG_ADDR_MIN]));
+
                 err = nft_validate_input_register(priv->sreg_addr_min);
                 if (err < 0)
                         return err;
-        }
 
-        if (tb[NFTA_NAT_REG_ADDR_MAX]) {
-                priv->sreg_addr_max = ntohl(nla_get_be32(
-                                                tb[NFTA_NAT_REG_ADDR_MAX]));
-                err = nft_validate_input_register(priv->sreg_addr_max);
-                if (err < 0)
-                        return err;
-        } else
-                priv->sreg_addr_max = priv->sreg_addr_min;
+                if (tb[NFTA_NAT_REG_ADDR_MAX]) {
+                        priv->sreg_addr_max =
+                                ntohl(nla_get_be32(tb[NFTA_NAT_REG_ADDR_MAX]));
+
+                        err = nft_validate_input_register(priv->sreg_addr_max);
+                        if (err < 0)
+                                return err;
+                } else {
+                        priv->sreg_addr_max = priv->sreg_addr_min;
+                }
+        }
 
         if (tb[NFTA_NAT_REG_PROTO_MIN]) {
-                priv->sreg_proto_min = ntohl(nla_get_be32(
-                                                tb[NFTA_NAT_REG_PROTO_MIN]));
+                priv->sreg_proto_min =
+                        ntohl(nla_get_be32(tb[NFTA_NAT_REG_PROTO_MIN]));
+
                 err = nft_validate_input_register(priv->sreg_proto_min);
                 if (err < 0)
                         return err;
-        }
 
-        if (tb[NFTA_NAT_REG_PROTO_MAX]) {
-                priv->sreg_proto_max = ntohl(nla_get_be32(
-                                                tb[NFTA_NAT_REG_PROTO_MAX]));
-                err = nft_validate_input_register(priv->sreg_proto_max);
-                if (err < 0)
-                        return err;
-        } else
-                priv->sreg_proto_max = priv->sreg_proto_min;
+                if (tb[NFTA_NAT_REG_PROTO_MAX]) {
+                        priv->sreg_proto_max =
+                                ntohl(nla_get_be32(tb[NFTA_NAT_REG_PROTO_MAX]));
+
+                        err = nft_validate_input_register(priv->sreg_proto_max);
+                        if (err < 0)
+                                return err;
+                } else {
+                        priv->sreg_proto_max = priv->sreg_proto_min;
+                }
+        }
 
         if (tb[NFTA_NAT_FLAGS]) {
                 priv->flags = ntohl(nla_get_be32(tb[NFTA_NAT_FLAGS]));
@@ -179,17 +191,19 @@ static int nft_nat_dump(struct sk_buff *skb, const struct nft_expr *expr)
 
         if (nla_put_be32(skb, NFTA_NAT_FAMILY, htonl(priv->family)))
                 goto nla_put_failure;
-        if (nla_put_be32(skb,
-                         NFTA_NAT_REG_ADDR_MIN, htonl(priv->sreg_addr_min)))
-                goto nla_put_failure;
-        if (nla_put_be32(skb,
-                         NFTA_NAT_REG_ADDR_MAX, htonl(priv->sreg_addr_max)))
-                goto nla_put_failure;
+
+        if (priv->sreg_addr_min) {
+                if (nla_put_be32(skb, NFTA_NAT_REG_ADDR_MIN,
+                                 htonl(priv->sreg_addr_min)) ||
+                    nla_put_be32(skb, NFTA_NAT_REG_ADDR_MAX,
+                                 htonl(priv->sreg_addr_max)))
+                        goto nla_put_failure;
+        }
+
         if (priv->sreg_proto_min) {
                 if (nla_put_be32(skb, NFTA_NAT_REG_PROTO_MIN,
-                                 htonl(priv->sreg_proto_min)))
-                        goto nla_put_failure;
-                if (nla_put_be32(skb, NFTA_NAT_REG_PROTO_MAX,
+                                 htonl(priv->sreg_proto_min)) ||
+                    nla_put_be32(skb, NFTA_NAT_REG_PROTO_MAX,
                                  htonl(priv->sreg_proto_max)))
                         goto nla_put_failure;
         }
@@ -205,6 +219,13 @@ nla_put_failure:
         return -1;
 }
 
+static int nft_nat_validate(const struct nft_ctx *ctx,
+                            const struct nft_expr *expr,
+                            const struct nft_data **data)
+{
+        return nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
+}
+
 static struct nft_expr_type nft_nat_type;
 static const struct nft_expr_ops nft_nat_ops = {
         .type           = &nft_nat_type,
@@ -212,6 +233,7 @@ static const struct nft_expr_ops nft_nat_ops = {
         .eval           = nft_nat_eval,
         .init           = nft_nat_init,
         .dump           = nft_nat_dump,
+        .validate       = nft_nat_validate,
 };
 
 static struct nft_expr_type nft_nat_type __read_mostly = {