[PATCH 6.12 055/567] netfilter: nf_conncount: fix leaked ct in error paths

Greg Kroah-Hartman
2026-01-06T17:17:18Z

From: Fernando Fernandez Mancera <fmancera@suse.de>

[ 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 <fmancera@suse.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 b84cfb5616df4..3c1b155f7a0ea 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 @@ static int __nf_conncount_add(struct net *net,
out_put:
if (refcounted)
nf_ct_put(ct);
- return 0;
+ return err;
}

int nf_conncount_add_skb(struct net *net,
@@ -446,11 +450,10 @@ insert_tree(struct net *net,

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;
}
--
2.51.0