netfilter: nf_conncount: fix leaked ct in error paths

There are some situations where ct might be leaked as error paths are
skipping the refcounted check and return immediately. In order to solve
it make sure that the check is always called.

Fixes: be102eb6a0e7 ("netfilter: nf_conncount: rework API to use sk_buff directly")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Florian Westphal <fw@strlen.de>

diff --git a/net/netfilter/nf_conncount.c b/net/netfilter/nf_conncount.c
index f1be4dd5cf85f5198233d365adffbbd91676bd43..3654f1e8976c915aec5a6ce4a0948cf12fd5a641 100644 (file)
--- a/net/netfilter/nf_conncount.c
+++ b/net/netfilter/nf_conncount.c
@@ -172,14 +172,14 @@ static int __nf_conncount_add(struct net *net,
        struct nf_conn *found_ct;
        unsigned int collect = 0;
        bool refcounted = false;
+       int err = 0;
 
        if (!get_ct_or_tuple_from_skb(net, skb, l3num, &ct, &tuple, &zone, &refcounted))
                return -ENOENT;
 
        if (ct && nf_ct_is_confirmed(ct)) {
-               if (refcounted)
-                       nf_ct_put(ct);
-               return -EEXIST;
+               err = -EEXIST;
+               goto out_put;
        }
 
        if ((u32)jiffies == list->last_gc)
@@ -231,12 +231,16 @@ static int __nf_conncount_add(struct net *net,
        }
 
 add_new_node:
-       if (WARN_ON_ONCE(list->count > INT_MAX))
-               return -EOVERFLOW;
+       if (WARN_ON_ONCE(list->count > INT_MAX)) {
+               err = -EOVERFLOW;
+               goto out_put;
+       }
 
        conn = kmem_cache_alloc(conncount_conn_cachep, GFP_ATOMIC);
-       if (conn == NULL)
-               return -ENOMEM;
+       if (conn == NULL) {
+               err = -ENOMEM;
+               goto out_put;
+       }
 
        conn->tuple = tuple;
        conn->zone = *zone;
@@ -249,7 +253,7 @@ add_new_node:
 out_put:
        if (refcounted)
                nf_ct_put(ct);
-       return 0;
+       return err;
 }
 
 int nf_conncount_add_skb(struct net *net,
@@ -456,11 +460,10 @@ restart:
 
                rb_link_node_rcu(&rbconn->node, parent, rbnode);
                rb_insert_color(&rbconn->node, root);
-
-               if (refcounted)
-                       nf_ct_put(ct);
        }
 out_unlock:
+       if (refcounted)
+               nf_ct_put(ct);
        spin_unlock_bh(&nf_conncount_locks[hash]);
        return count;
 }