Merge tag 'irq-urgent-2020-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git...

[linux.git] / net / netfilter / xt_hashlimit.c

diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c
index bccd47cd7190810af06dea672842be7f58f72a4e..7a2c4b8408c498aa04e0f7888dbaab8b6cb4faad 100644 (file)
--- a/net/netfilter/xt_hashlimit.c
+++ b/net/netfilter/xt_hashlimit.c
@@ -36,6 +36,7 @@
 #include <linux/netfilter_ipv6/ip6_tables.h>
 #include <linux/mutex.h>
 #include <linux/kernel.h>
+#include <linux/refcount.h>
 #include <uapi/linux/netfilter/xt_hashlimit.h>
 
 #define XT_HASHLIMIT_ALL (XT_HASHLIMIT_HASH_DIP | XT_HASHLIMIT_HASH_DPT | \
@@ -114,7 +115,7 @@ struct dsthash_ent {
 
 struct xt_hashlimit_htable {
        struct hlist_node node;         /* global list of all htables */
-       int use;
+       refcount_t use;
        u_int8_t family;
        bool rnd_initialized;
 
@@ -315,7 +316,7 @@ static int htable_create(struct net *net, struct hashlimit_cfg3 *cfg,
        for (i = 0; i < hinfo->cfg.size; i++)
                INIT_HLIST_HEAD(&hinfo->hash[i]);
 
-       hinfo->use = 1;
+       refcount_set(&hinfo->use, 1);
        hinfo->count = 0;
        hinfo->family = family;
        hinfo->rnd_initialized = false;
@@ -420,7 +421,7 @@ static struct xt_hashlimit_htable *htable_find_get(struct net *net,
        hlist_for_each_entry(hinfo, &hashlimit_net->htables, node) {
                if (!strcmp(name, hinfo->name) &&
                    hinfo->family == family) {
-                       hinfo->use++;
+                       refcount_inc(&hinfo->use);
                        return hinfo;
                }
        }
@@ -429,12 +430,11 @@ static struct xt_hashlimit_htable *htable_find_get(struct net *net,
 
 static void htable_put(struct xt_hashlimit_htable *hinfo)
 {
-       mutex_lock(&hashlimit_mutex);
-       if (--hinfo->use == 0) {
+       if (refcount_dec_and_mutex_lock(&hinfo->use, &hashlimit_mutex)) {
                hlist_del(&hinfo->node);
+               mutex_unlock(&hashlimit_mutex);
                htable_destroy(hinfo);
        }
-       mutex_unlock(&hashlimit_mutex);
 }
 
 /* The algorithm used is the Simple Token Bucket Filter (TBF)
@@ -837,6 +837,8 @@ hashlimit_mt(const struct sk_buff *skb, struct xt_action_param *par)
        return hashlimit_mt_common(skb, par, hinfo, &info->cfg, 3);
 }
 
+#define HASHLIMIT_MAX_SIZE 1048576
+
 static int hashlimit_mt_check_common(const struct xt_mtchk_param *par,
                                     struct xt_hashlimit_htable **hinfo,
                                     struct hashlimit_cfg3 *cfg,
@@ -847,6 +849,14 @@ static int hashlimit_mt_check_common(const struct xt_mtchk_param *par,
 
        if (cfg->gc_interval == 0 || cfg->expire == 0)
                return -EINVAL;
+       if (cfg->size > HASHLIMIT_MAX_SIZE) {
+               cfg->size = HASHLIMIT_MAX_SIZE;
+               pr_info_ratelimited("size too large, truncated to %u\n", cfg->size);
+       }
+       if (cfg->max > HASHLIMIT_MAX_SIZE) {
+               cfg->max = HASHLIMIT_MAX_SIZE;
+               pr_info_ratelimited("max too large, truncated to %u\n", cfg->max);
+       }
        if (par->family == NFPROTO_IPV4) {
                if (cfg->srcmask > 32 || cfg->dstmask > 32)
                        return -EINVAL;