netfilter: xtables: slightly better error reporting

When extended status codes are available, such as ENOMEM on failed
allocations, or subsequent functions (e.g. nf_ct_get_l3proto), passing
them up to userspace seems like a good idea compared to just always
EINVAL.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>

24 files changed, 101 insertions, 56 deletions

diff --git a/net/netfilter/xt_CONNSECMARK.c b/net/netfilter/xt_CONNSECMARK.c
index 2287a82a0703..105a62e985d3 100644
--- a/net/netfilter/xt_CONNSECMARK.c
+++ b/net/netfilter/xt_CONNSECMARK.c
@@ -87,6 +87,7 @@ connsecmark_tg(struct sk_buff *skb, const struct xt_target_param *par)
 static int connsecmark_tg_check(const struct xt_tgchk_param *par)
 {
         const struct xt_connsecmark_target_info *info = par->targinfo;
+        int ret;
 
         if (strcmp(par->table, "mangle") != 0 &&
             strcmp(par->table, "security") != 0) {
@@ -102,13 +103,14 @@ static int connsecmark_tg_check(const struct xt_tgchk_param *par)
 
         default:
                 pr_info("invalid mode: %hu\n", info->mode);
-                return false;
+                return -EINVAL;
         }
 
-        if (nf_ct_l3proto_try_module_get(par->family) < 0) {
+        ret = nf_ct_l3proto_try_module_get(par->family);
+        if (ret < 0) {
                 pr_info("cannot load conntrack support for proto=%u\n",
                         par->family);
-                return -EINVAL;
+                return ret;
         }
         return 0;
 }
diff --git a/net/netfilter/xt_CT.c b/net/netfilter/xt_CT.c
index ee566e2e4534..65dd348ae361 100644
--- a/net/netfilter/xt_CT.c
+++ b/net/netfilter/xt_CT.c
@@ -59,6 +59,7 @@ static int xt_ct_tg_check(const struct xt_tgchk_param *par)
         struct nf_conntrack_tuple t;
         struct nf_conn_help *help;
         struct nf_conn *ct;
+        int ret = 0;
         u8 proto;
 
         if (info->flags & ~XT_CT_NOTRACK)
@@ -75,28 +76,34 @@ static int xt_ct_tg_check(const struct xt_tgchk_param *par)
                 goto err1;
 #endif
 
-        if (nf_ct_l3proto_try_module_get(par->family) < 0)
+        ret = nf_ct_l3proto_try_module_get(par->family);
+        if (ret < 0)
                 goto err1;
 
         memset(&t, 0, sizeof(t));
         ct = nf_conntrack_alloc(par->net, info->zone, &t, &t, GFP_KERNEL);
+        ret = PTR_ERR(ct);
         if (IS_ERR(ct))
                 goto err2;
 
+        ret = 0;
         if ((info->ct_events || info->exp_events) &&
             !nf_ct_ecache_ext_add(ct, info->ct_events, info->exp_events,
                                   GFP_KERNEL))
                 goto err3;
 
         if (info->helper[0]) {
+                ret = -ENOENT;
                 proto = xt_ct_find_proto(par);
                 if (!proto)
                         goto err3;
 
+                ret = -ENOMEM;
                 help = nf_ct_helper_ext_add(ct, GFP_KERNEL);
                 if (help == NULL)
                         goto err3;
 
+                ret = -ENOENT;
                 help->helper = nf_conntrack_helper_try_module_get(info->helper,
                                                                   par->family,
                                                                   proto);
@@ -115,7 +122,7 @@ err3:
 err2:
         nf_ct_l3proto_module_put(par->family);
 err1:
-        return -EINVAL;
+        return ret;
 }
 
 static void xt_ct_tg_destroy(const struct xt_tgdtor_param *par)
diff --git a/net/netfilter/xt_DSCP.c b/net/netfilter/xt_DSCP.c
index aa263b80f8c0..969634f293e5 100644
--- a/net/netfilter/xt_DSCP.c
+++ b/net/netfilter/xt_DSCP.c
@@ -66,7 +66,7 @@ static int dscp_tg_check(const struct xt_tgchk_param *par)
 
         if (info->dscp > XT_DSCP_MAX) {
                 pr_info("dscp %x out of range\n", info->dscp);
-                return -EINVAL;
+                return -EDOM;
         }
         return 0;
 }
diff --git a/net/netfilter/xt_HL.c b/net/netfilter/xt_HL.c
index 7a47383ec723..77b99f732711 100644
--- a/net/netfilter/xt_HL.c
+++ b/net/netfilter/xt_HL.c
@@ -107,7 +107,7 @@ static int ttl_tg_check(const struct xt_tgchk_param *par)
 
         if (info->mode > IPT_TTL_MAXMODE) {
                 pr_info("TTL: invalid or unknown mode %u\n", info->mode);
-                return false;
+                return -EINVAL;
         }
         if (info->mode != IPT_TTL_SET && info->ttl == 0)
                 return -EINVAL;
diff --git a/net/netfilter/xt_LED.c b/net/netfilter/xt_LED.c
index 22b5b7057397..efcf56db23e8 100644
--- a/net/netfilter/xt_LED.c
+++ b/net/netfilter/xt_LED.c
@@ -93,7 +93,7 @@ static int led_tg_check(const struct xt_tgchk_param *par)
 
         ledinternal = kzalloc(sizeof(struct xt_led_info_internal), GFP_KERNEL);
         if (!ledinternal)
-                return -EINVAL;
+                return -ENOMEM;
 
         ledinternal->netfilter_led_trigger.name = ledinfo->id;
 
@@ -115,7 +115,7 @@ static int led_tg_check(const struct xt_tgchk_param *par)
 
 exit_alloc:
         kfree(ledinternal);
-        return -EINVAL;
+        return err;
 }
 
 static void led_tg_destroy(const struct xt_tgdtor_param *par)
diff --git a/net/netfilter/xt_NFQUEUE.c b/net/netfilter/xt_NFQUEUE.c
index add1789ae4a8..f9217cb56fe3 100644
--- a/net/netfilter/xt_NFQUEUE.c
+++ b/net/netfilter/xt_NFQUEUE.c
@@ -98,7 +98,7 @@ static int nfqueue_tg_v1_check(const struct xt_tgchk_param *par)
         if (maxid > 0xffff) {
                 pr_err("NFQUEUE: number of queues (%u) out of range (got %u)\n",
                        info->queues_total, maxid);
-                return -EINVAL;
+                return -ERANGE;
         }
         return 0;
 }
diff --git a/net/netfilter/xt_RATEEST.c b/net/netfilter/xt_RATEEST.c
index 7af5fba39cdd..40751c618e70 100644
--- a/net/netfilter/xt_RATEEST.c
+++ b/net/netfilter/xt_RATEEST.c
@@ -93,6 +93,7 @@ static int xt_rateest_tg_checkentry(const struct xt_tgchk_param *par)
                 struct nlattr           opt;
                 struct gnet_estimator   est;
         } cfg;
+        int ret;
 
         if (unlikely(!rnd_inited)) {
                 get_random_bytes(&jhash_rnd, sizeof(jhash_rnd));
@@ -115,6 +116,7 @@ static int xt_rateest_tg_checkentry(const struct xt_tgchk_param *par)
                 return 0;
         }
 
+        ret = -ENOMEM;
         est = kzalloc(sizeof(*est), GFP_KERNEL);
         if (!est)
                 goto err1;
@@ -130,8 +132,9 @@ static int xt_rateest_tg_checkentry(const struct xt_tgchk_param *par)
         cfg.est.interval        = info->interval;
         cfg.est.ewma_log        = info->ewma_log;
 
-        if (gen_new_estimator(&est->bstats, &est->rstats, &est->lock,
-                              &cfg.opt) < 0)
+        ret = gen_new_estimator(&est->bstats, &est->rstats,
+                                &est->lock, &cfg.opt);
+        if (ret < 0)
                 goto err2;
 
         info->est = est;
@@ -141,7 +144,7 @@ static int xt_rateest_tg_checkentry(const struct xt_tgchk_param *par)
 err2:
         kfree(est);
 err1:
-        return -EINVAL;
+        return ret;
 }
 
 static void xt_rateest_tg_destroy(const struct xt_tgdtor_param *par)
diff --git a/net/netfilter/xt_SECMARK.c b/net/netfilter/xt_SECMARK.c
index 39098fc9887d..a91d4a7d5a2c 100644
--- a/net/netfilter/xt_SECMARK.c
+++ b/net/netfilter/xt_SECMARK.c
@@ -50,7 +50,7 @@ secmark_tg(struct sk_buff *skb, const struct xt_target_param *par)
         return XT_CONTINUE;
 }
 
-static bool checkentry_selinux(struct xt_secmark_target_info *info)
+static int checkentry_selinux(struct xt_secmark_target_info *info)
 {
         int err;
         struct xt_secmark_target_selinux_info *sel = &info->u.sel;
@@ -62,27 +62,28 @@ static bool checkentry_selinux(struct xt_secmark_target_info *info)
                 if (err == -EINVAL)
                         pr_info("invalid SELinux context \'%s\'\n",
                                 sel->selctx);
-                return false;
+                return err;
         }
 
         if (!sel->selsid) {
                 pr_info("unable to map SELinux context \'%s\'\n", sel->selctx);
-                return false;
+                return -ENOENT;
         }
 
         err = selinux_secmark_relabel_packet_permission(sel->selsid);
         if (err) {
                 pr_info("unable to obtain relabeling permission\n");
-                return false;
+                return err;
         }
 
         selinux_secmark_refcount_inc();
-        return true;
+        return 0;
 }
 
 static int secmark_tg_check(const struct xt_tgchk_param *par)
 {
         struct xt_secmark_target_info *info = par->targinfo;
+        int err;
 
         if (strcmp(par->table, "mangle") != 0 &&
             strcmp(par->table, "security") != 0) {
@@ -99,8 +100,9 @@ static int secmark_tg_check(const struct xt_tgchk_param *par)
 
         switch (info->mode) {
         case SECMARK_MODE_SEL:
-                if (!checkentry_selinux(info))
-                        return -EINVAL;
+                err = checkentry_selinux(info);
+                if (err <= 0)
+                        return err;
                 break;
 
         default:
diff --git a/net/netfilter/xt_cluster.c b/net/netfilter/xt_cluster.c
index 30cb7762fc41..6c941e1c6b9e 100644
--- a/net/netfilter/xt_cluster.c
+++ b/net/netfilter/xt_cluster.c
@@ -145,7 +145,7 @@ static int xt_cluster_mt_checkentry(const struct xt_mtchk_param *par)
         if (info->node_mask >= (1ULL << info->total_nodes)) {
                 pr_info("this node mask cannot be "
                         "higher than the total number of nodes\n");
-                return -EINVAL;
+                return -EDOM;
         }
         return 0;
 }
diff --git a/net/netfilter/xt_connbytes.c b/net/netfilter/xt_connbytes.c
index bf8e286361c3..2ff332ecc342 100644
--- a/net/netfilter/xt_connbytes.c
+++ b/net/netfilter/xt_connbytes.c
@@ -96,6 +96,7 @@ connbytes_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 static int connbytes_mt_check(const struct xt_mtchk_param *par)
 {
         const struct xt_connbytes_info *sinfo = par->matchinfo;
+        int ret;
 
         if (sinfo->what != XT_CONNBYTES_PKTS &&
             sinfo->what != XT_CONNBYTES_BYTES &&
@@ -107,10 +108,11 @@ static int connbytes_mt_check(const struct xt_mtchk_param *par)
             sinfo->direction != XT_CONNBYTES_DIR_BOTH)
                 return -EINVAL;
 
-        if (nf_ct_l3proto_try_module_get(par->family) < 0) {
+        ret = nf_ct_l3proto_try_module_get(par->family);
+        if (ret < 0) {
                 pr_info("cannot load conntrack support for proto=%u\n",
                         par->family);
-                return -EINVAL;
+                return ret;
         }
 
         return 0;
diff --git a/net/netfilter/xt_connlimit.c b/net/netfilter/xt_connlimit.c
index 68e89f08140b..370088ec5764 100644
--- a/net/netfilter/xt_connlimit.c
+++ b/net/netfilter/xt_connlimit.c
@@ -220,22 +220,24 @@ static int connlimit_mt_check(const struct xt_mtchk_param *par)
 {
         struct xt_connlimit_info *info = par->matchinfo;
         unsigned int i;
+        int ret;
 
         if (unlikely(!connlimit_rnd_inited)) {
                 get_random_bytes(&connlimit_rnd, sizeof(connlimit_rnd));
                 connlimit_rnd_inited = true;
         }
-        if (nf_ct_l3proto_try_module_get(par->family) < 0) {
+        ret = nf_ct_l3proto_try_module_get(par->family);
+        if (ret < 0) {
                 pr_info("cannot load conntrack support for "
                         "address family %u\n", par->family);
-                return -EINVAL;
+                return ret;
         }
 
         /* init private data */
         info->data = kmalloc(sizeof(struct xt_connlimit_data), GFP_KERNEL);
         if (info->data == NULL) {
                 nf_ct_l3proto_module_put(par->family);
-                return -EINVAL;
+                return -ENOMEM;
         }
 
         spin_lock_init(&info->data->lock);
diff --git a/net/netfilter/xt_connmark.c b/net/netfilter/xt_connmark.c
index e137af5559e0..71e38a1fd656 100644
--- a/net/netfilter/xt_connmark.c
+++ b/net/netfilter/xt_connmark.c
@@ -76,10 +76,13 @@ connmark_tg(struct sk_buff *skb, const struct xt_target_param *par)
 
 static int connmark_tg_check(const struct xt_tgchk_param *par)
 {
-        if (nf_ct_l3proto_try_module_get(par->family) < 0) {
+        int ret;
+
+        ret = nf_ct_l3proto_try_module_get(par->family);
+        if (ret < 0) {
                 pr_info("cannot load conntrack support for proto=%u\n",
                         par->family);
-                return -EINVAL;
+                return ret;
         }
         return 0;
 }
@@ -105,10 +108,13 @@ connmark_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 
 static int connmark_mt_check(const struct xt_mtchk_param *par)
 {
-        if (nf_ct_l3proto_try_module_get(par->family) < 0) {
+        int ret;
+
+        ret = nf_ct_l3proto_try_module_get(par->family);
+        if (ret < 0) {
                 pr_info("cannot load conntrack support for proto=%u\n",
                         par->family);
-                return -EINVAL;
+                return ret;
         }
         return 0;
 }
diff --git a/net/netfilter/xt_conntrack.c b/net/netfilter/xt_conntrack.c
index 26e34aa7f8d1..e0bcf8d2cf33 100644
--- a/net/netfilter/xt_conntrack.c
+++ b/net/netfilter/xt_conntrack.c
@@ -208,10 +208,13 @@ conntrack_mt_v2(const struct sk_buff *skb, const struct xt_match_param *par)
 
 static int conntrack_mt_check(const struct xt_mtchk_param *par)
 {
-        if (nf_ct_l3proto_try_module_get(par->family) < 0) {
+        int ret;
+
+        ret = nf_ct_l3proto_try_module_get(par->family);
+        if (ret < 0) {
                 pr_info("cannot load conntrack support for proto=%u\n",
                         par->family);
-                return -EINVAL;
+                return ret;
         }
         return 0;
 }
diff --git a/net/netfilter/xt_dscp.c b/net/netfilter/xt_dscp.c
index f355fb9e06fa..9db51fddbdb8 100644
--- a/net/netfilter/xt_dscp.c
+++ b/net/netfilter/xt_dscp.c
@@ -48,7 +48,7 @@ static int dscp_mt_check(const struct xt_mtchk_param *par)
 
         if (info->dscp > XT_DSCP_MAX) {
                 pr_info("dscp %x out of range\n", info->dscp);
-                return -EINVAL;
+                return -EDOM;
         }
 
         return 0;
diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c
index 0c0152902b3b..c89fde7d1234 100644
--- a/net/netfilter/xt_hashlimit.c
+++ b/net/netfilter/xt_hashlimit.c
@@ -214,7 +214,7 @@ static int htable_create_v0(struct net *net, struct xt_hashlimit_info *minfo, u_
         hinfo = vmalloc(sizeof(struct xt_hashlimit_htable) +
                         sizeof(struct list_head) * size);
         if (!hinfo)
-                return -1;
+                return -ENOMEM;
         minfo->hinfo = hinfo;
 
         /* copy match config into hashtable config */
@@ -250,7 +250,7 @@ static int htable_create_v0(struct net *net, struct xt_hashlimit_info *minfo, u_
                 &dl_file_ops, hinfo);
         if (!hinfo->pde) {
                 vfree(hinfo);
-                return -1;
+                return -ENOMEM;
         }
         hinfo->net = net;
 
@@ -285,7 +285,7 @@ static int htable_create(struct net *net, struct xt_hashlimit_mtinfo1 *minfo,
         hinfo = vmalloc(sizeof(struct xt_hashlimit_htable) +
                         sizeof(struct list_head) * size);
         if (hinfo == NULL)
-                return -1;
+                return -ENOMEM;
         minfo->hinfo = hinfo;
 
         /* copy match config into hashtable config */
@@ -311,7 +311,7 @@ static int htable_create(struct net *net, struct xt_hashlimit_mtinfo1 *minfo,
                 &dl_file_ops, hinfo);
         if (hinfo->pde == NULL) {
                 vfree(hinfo);
-                return -1;
+                return -ENOMEM;
         }
         hinfo->net = net;
 
@@ -675,13 +675,14 @@ static int hashlimit_mt_check_v0(const struct xt_mtchk_param *par)
 {
         struct net *net = par->net;
         struct xt_hashlimit_info *r = par->matchinfo;
+        int ret;
 
         /* Check for overflow. */
         if (r->cfg.burst == 0 ||
             user2credits(r->cfg.avg * r->cfg.burst) < user2credits(r->cfg.avg)) {
                 pr_info("overflow, try lower: %u/%u\n",
                         r->cfg.avg, r->cfg.burst);
-                return -EINVAL;
+                return -ERANGE;
         }
         if (r->cfg.mode == 0 ||
             r->cfg.mode > (XT_HASHLIMIT_HASH_DPT |
@@ -698,9 +699,12 @@ static int hashlimit_mt_check_v0(const struct xt_mtchk_param *par)
 
         mutex_lock(&hashlimit_mutex);
         r->hinfo = htable_find_get(net, r->name, par->family);
-        if (!r->hinfo && htable_create_v0(net, r, par->family) != 0) {
-                mutex_unlock(&hashlimit_mutex);
-                return -EINVAL;
+        if (r->hinfo == NULL) {
+                ret = htable_create_v0(net, r, par->family);
+                if (ret < 0) {
+                        mutex_unlock(&hashlimit_mutex);
+                        return ret;
+                }
         }
         mutex_unlock(&hashlimit_mutex);
         return 0;
@@ -710,6 +714,7 @@ static int hashlimit_mt_check(const struct xt_mtchk_param *par)
 {
         struct net *net = par->net;
         struct xt_hashlimit_mtinfo1 *info = par->matchinfo;
+        int ret;
 
         /* Check for overflow. */
         if (info->cfg.burst == 0 ||
@@ -717,7 +722,7 @@ static int hashlimit_mt_check(const struct xt_mtchk_param *par)
             user2credits(info->cfg.avg)) {
                 pr_info("overflow, try lower: %u/%u\n",
                         info->cfg.avg, info->cfg.burst);
-                return -EINVAL;
+                return -ERANGE;
         }
         if (info->cfg.gc_interval == 0 || info->cfg.expire == 0)
                 return -EINVAL;
@@ -733,9 +738,12 @@ static int hashlimit_mt_check(const struct xt_mtchk_param *par)
 
         mutex_lock(&hashlimit_mutex);
         info->hinfo = htable_find_get(net, info->name, par->family);
-        if (!info->hinfo && htable_create(net, info, par->family) != 0) {
-                mutex_unlock(&hashlimit_mutex);
-                return -EINVAL;
+        if (info->hinfo == NULL) {
+                ret = htable_create(net, info, par->family);
+                if (ret < 0) {
+                        mutex_unlock(&hashlimit_mutex);
+                        return ret;
+                }
         }
         mutex_unlock(&hashlimit_mutex);
         return 0;
diff --git a/net/netfilter/xt_helper.c b/net/netfilter/xt_helper.c
index eb308b32bfe0..b8b3e13dc71e 100644
--- a/net/netfilter/xt_helper.c
+++ b/net/netfilter/xt_helper.c
@@ -57,11 +57,13 @@ helper_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 static int helper_mt_check(const struct xt_mtchk_param *par)
 {
         struct xt_helper_info *info = par->matchinfo;
+        int ret;
 
-        if (nf_ct_l3proto_try_module_get(par->family) < 0) {
+        ret = nf_ct_l3proto_try_module_get(par->family);
+        if (ret < 0) {
                 pr_info("cannot load conntrack support for proto=%u\n",
                         par->family);
-                return -EINVAL;
+                return ret;
         }
         info->name[29] = '\0';
         return 0;
diff --git a/net/netfilter/xt_limit.c b/net/netfilter/xt_limit.c
index 5ff0580ce878..e2a284ebb415 100644
--- a/net/netfilter/xt_limit.c
+++ b/net/netfilter/xt_limit.c
@@ -107,12 +107,12 @@ static int limit_mt_check(const struct xt_mtchk_param *par)
             || user2credits(r->avg * r->burst) < user2credits(r->avg)) {
                 pr_info("Overflow, try lower: %u/%u\n",
                         r->avg, r->burst);
-                return -EINVAL;
+                return -ERANGE;
         }
 
         priv = kmalloc(sizeof(*priv), GFP_KERNEL);
         if (priv == NULL)
-                return -EINVAL;
+                return -ENOMEM;
 
         /* For SMP, we only want to use one set of state. */
         r->master = priv;
diff --git a/net/netfilter/xt_quota.c b/net/netfilter/xt_quota.c
index 766e71c6dc55..3e5cbd85a65b 100644
--- a/net/netfilter/xt_quota.c
+++ b/net/netfilter/xt_quota.c
@@ -52,7 +52,7 @@ static int quota_mt_check(const struct xt_mtchk_param *par)
 
         q->master = kmalloc(sizeof(*q->master), GFP_KERNEL);
         if (q->master == NULL)
-                return -EINVAL;
+                return -ENOMEM;
 
         q->master->quota = q->quota;
         return 0;
diff --git a/net/netfilter/xt_rateest.c b/net/netfilter/xt_rateest.c
index 0b5c6122737d..23805f8a444b 100644
--- a/net/netfilter/xt_rateest.c
+++ b/net/netfilter/xt_rateest.c
@@ -78,6 +78,7 @@ static int xt_rateest_mt_checkentry(const struct xt_mtchk_param *par)
 {
         struct xt_rateest_match_info *info = par->matchinfo;
         struct xt_rateest *est1, *est2;
+        int ret = false;
 
         if (hweight32(info->flags & (XT_RATEEST_MATCH_ABS |
                                      XT_RATEEST_MATCH_REL)) != 1)
@@ -95,6 +96,7 @@ static int xt_rateest_mt_checkentry(const struct xt_mtchk_param *par)
                 goto err1;
         }
 
+        ret  = -ENOENT;
         est1 = xt_rateest_lookup(info->name1);
         if (!est1)
                 goto err1;
diff --git a/net/netfilter/xt_recent.c b/net/netfilter/xt_recent.c
index 0994ff54a731..0d9f80b1dd9f 100644
--- a/net/netfilter/xt_recent.c
+++ b/net/netfilter/xt_recent.c
@@ -355,8 +355,10 @@ static int recent_mt_check(const struct xt_mtchk_param *par)
 
         t = kzalloc(sizeof(*t) + sizeof(t->iphash[0]) * ip_list_hash_size,
                     GFP_KERNEL);
-        if (t == NULL)
+        if (t == NULL) {
+                ret = -ENOMEM;
                 goto out;
+        }
         t->refcnt = 1;
         strcpy(t->name, info->name);
         INIT_LIST_HEAD(&t->lru_list);
@@ -367,6 +369,7 @@ static int recent_mt_check(const struct xt_mtchk_param *par)
                   &recent_mt_fops, t);
         if (pde == NULL) {
                 kfree(t);
+                ret = -ENOMEM;
                 goto out;
         }
         pde->uid = ip_list_uid;
diff --git a/net/netfilter/xt_state.c b/net/netfilter/xt_state.c
index 8e8c9df51784..2b75230d15ca 100644
--- a/net/netfilter/xt_state.c
+++ b/net/netfilter/xt_state.c
@@ -39,10 +39,13 @@ state_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 
 static int state_mt_check(const struct xt_mtchk_param *par)
 {
-        if (nf_ct_l3proto_try_module_get(par->family) < 0) {
+        int ret;
+
+        ret = nf_ct_l3proto_try_module_get(par->family);
+        if (ret < 0) {
                 pr_info("cannot load conntrack support for proto=%u\n",
                         par->family);
-                return -EINVAL;
+                return ret;
         }
         return 0;
 }
diff --git a/net/netfilter/xt_statistic.c b/net/netfilter/xt_statistic.c
index 29d76f8f1880..8ed2b2905091 100644
--- a/net/netfilter/xt_statistic.c
+++ b/net/netfilter/xt_statistic.c
@@ -62,7 +62,7 @@ static int statistic_mt_check(const struct xt_mtchk_param *par)
 
         info->master = kzalloc(sizeof(*info->master), GFP_KERNEL);
         if (info->master == NULL)
-                return -EINVAL;
+                return -ENOMEM;
         info->master->count = info->u.nth.count;
 
         return 0;
diff --git a/net/netfilter/xt_string.c b/net/netfilter/xt_string.c
index e1f22a7a4152..b0f8292db6f8 100644
--- a/net/netfilter/xt_string.c
+++ b/net/netfilter/xt_string.c
@@ -63,7 +63,7 @@ static int string_mt_check(const struct xt_mtchk_param *par)
         ts_conf = textsearch_prepare(conf->algo, conf->pattern, conf->patlen,
                                      GFP_KERNEL, flags);
         if (IS_ERR(ts_conf))
-                return -EINVAL;
+                return PTR_ERR(ts_conf);
 
         conf->config = ts_conf;
         return 0;
diff --git a/net/netfilter/xt_time.c b/net/netfilter/xt_time.c
index 8dde5e51ff19..d8556fdda440 100644
--- a/net/netfilter/xt_time.c
+++ b/net/netfilter/xt_time.c
@@ -225,7 +225,7 @@ static int time_mt_check(const struct xt_mtchk_param *par)
             info->daytime_stop > XT_TIME_MAX_DAYTIME) {
                 pr_info("invalid argument - start or "
                         "stop time greater than 23:59:59\n");
-                return -EINVAL;
+                return -EDOM;
         }
 
         return 0;