From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.netfilter.org (mail.netfilter.org [217.70.190.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 57924456DFD for ; Wed, 2 Sep 2026 23:29:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.190.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788391744; cv=none; b=DMP9BoD4F96hsDYMydt/Sr1JGglXa1R+0NrfQv9L7vryC7mdFBEl8iPbhFH3KgpudlEkRcl0afLe1z5BRK/firbcslYCEgqRFe1JYy7CebILf1imxwacB/UvFOY4U2CZ1ls5P/eiO0RTq3aTgYoJxWnql+Mkr1OeGCCN32Oe4XE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788391744; c=relaxed/simple; bh=LL8pbPdrWbhhlH+5ffJWUChV53Z+3Rw3I0onLUflIE8=; h=From:To:Subject:Date:Message-ID:MIME-Version; b=uJqSCHf+rjNOtDeBBt6JOPfO8nT2mpMYn8DT3z/Ekn0NThwGtd2WTjuVXdQ53Ewg4H+dGFmR6M/d6NYx0zhCs8MreAzfTXX0EblHjeIrkD6OJ6YCRSsGHvZlFPAq7W1B9JJhtalcoTu7sZlPYkWT1vl2rHNViea3WejHMIkshqY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org; spf=pass smtp.mailfrom=netfilter.org; dkim=pass (2048-bit key) header.d=netfilter.org header.i=@netfilter.org header.b=ox73vmJJ; arc=none smtp.client-ip=217.70.190.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=netfilter.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=netfilter.org header.i=@netfilter.org header.b="ox73vmJJ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netfilter.org; s=2025; t=1788391739; bh=neY56JQMPcLC3MCc9wXvRxN37SAej1AxhR+6MkKn7ZU=; h=From:To:Subject:Date:From; b=ox73vmJJc+1OT8Hmjuf3pLKOJhnD4rGfhEhk1c9IlBnTwpmj0EN0UYxzph2qJVexc s5NCCqBhZ8nzLGyySRgHgBp9jwQl1dnrXziJYljvduOCkliFqFHqVomw1LgRD3affs ro+8N47+KSVWRdmEnuHVThHaXQEVNR/U1GqX3BEeZaoTg5HhuGdoKMh0W2Q/mNRLQ7 8qJajYwKoNHbXTZzJiT6WiL/r2DSXDvKmtzCW0rHmOxXKfRPblEjE1MTI6tNO6pz0Y a2etWQmNmXN8N3of/nfYlKiQyRs/1usQJuKOqV8cd1tKZf4DPmoZjvjLmpkfokSWFn LWH2ssVk4/bLg== Received: from localhost.localdomain (mail-agni [217.70.190.124]) by mail.netfilter.org (Postfix) with ESMTPSA id 80612607A7 for ; Thu, 3 Sep 2026 01:28:59 +0200 (CEST) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Subject: [PATCH nf,v3] netfilter: nf_nat: unregister and release hooks on error Date: Thu, 3 Sep 2026 01:28:56 +0200 Message-ID: <20260902232856.1024959-1-pablo@netfilter.org> X-Mailer: git-send-email 2.47.3 Precedence: bulk X-Mailing-List: netfilter-devel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit After the base nat hooks are registered, the first nested nat hook is added through nf_hook_entries_insert_raw() and ->users is bumped. However, sashiko reports that nf_hook_entries_insert_raw() fails, then ->users count remains at zero and nf_nat_unregister_fn() could hit WARN_ON() since base nat hooks with no users is unexpected in the unregistration path. Postpone setting nat_proto_net->nat_hook_ops when the hooks are registered to simplify the error path to decide whether the nat hooks need unwinding. Fixes: 1cd472bf036c ("netfilter: nf_nat: add nat hook register functions to nf_nat") Signed-off-by: Pablo Neira Ayuso --- v3: missing else to nat_ops = nat_proto_net->nat_hook_ops conditionally. net/netfilter/nf_nat_core.c | 46 ++++++++++++++++++++++++------------- 1 file changed, 30 insertions(+), 16 deletions(-) diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c index 8ac326e1eb5b..a4858c2b2d65 100644 --- a/net/netfilter/nf_nat_core.c +++ b/net/netfilter/nf_nat_core.c @@ -1224,31 +1224,45 @@ int nf_nat_register_fn(struct net *net, u8 pf, const struct nf_hook_ops *ops, } ret = nf_register_net_hooks(net, nat_ops, ops_count); - if (ret < 0) { - mutex_unlock(&nf_nat_proto_mutex); - for (i = 0; i < ops_count; i++) { - priv = nat_ops[i].priv; - kfree_rcu(priv, rcu_head); - } - kfree_rcu(nat_ops, rcu); - return ret; - } - - nat_proto_net->nat_hook_ops = nat_ops; + if (ret < 0) + goto err_free_hooks; + } else { + nat_ops = nat_proto_net->nat_hook_ops; } - nat_ops = nat_proto_net->nat_hook_ops; priv = nat_ops[hooknum].priv; if (WARN_ON_ONCE(!priv)) { - mutex_unlock(&nf_nat_proto_mutex); - return -EOPNOTSUPP; + ret = -EOPNOTSUPP; + goto err_unregister_hooks; } ret = nf_hook_entries_insert_raw(&priv->entries, ops); - if (ret == 0) - nat_proto_net->users++; + if (ret) + goto err_unregister_hooks; + + if (!nat_proto_net->nat_hook_ops) + nat_proto_net->nat_hook_ops = nat_ops; + + nat_proto_net->users++; mutex_unlock(&nf_nat_proto_mutex); + + return 0; + +err_unregister_hooks: + if (nat_proto_net->nat_hook_ops) { + mutex_unlock(&nf_nat_proto_mutex); + return ret; + } + nf_unregister_net_hooks(net, nat_ops, ops_count); +err_free_hooks: + mutex_unlock(&nf_nat_proto_mutex); + for (i = 0; i < ops_count; i++) { + priv = nat_ops[i].priv; + kfree_rcu(priv, rcu_head); + } + kfree_rcu(nat_ops, rcu); + return ret; } -- 2.47.3