From 4bd2b89f4028f250dd1c1625eb3da1979b04a5e8 Mon Sep 17 00:00:00 2001 From: Fernando Fernandez Mancera Date: Fri, 5 Dec 2025 12:58:01 +0100 Subject: [PATCH] netfilter: nf_conncount: fix leaked ct in error paths [ Upstream commit 2e2a720766886190a6d35c116794693aabd332b6 ] 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 Signed-off-by: Florian Westphal Signed-off-by: Sasha Levin --- net/netfilter/nf_conncount.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) diff --git a/net/netfilter/nf_conncount.c b/net/netfilter/nf_conncount.c index b84cfb5616df..3c1b155f7a0e 100644 --- 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, @@ -446,11 +450,10 @@ 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; }