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 9D95B420479 for ; Wed, 2 Sep 2026 23:06:46 +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=1788390411; cv=none; b=MXpPb8rbO+yJEKExLBaw3kI3zlkWD2/uZopJvuXDXX3W0X7K5FE3SELe0LNSZALC0nRuI5GmHL7GimwZfopVQ1MeTBNpuUdGfsAhSCPypjOFy1waAhlS/W8CJqxJBqc7IR0t3f+h1Qkq5kl3DBwAg8B1nsxO/814pgG1fQOvL5Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788390411; c=relaxed/simple; bh=uQ9BqwG75WrewC2P1qBCZIrNDe3U5Eo+jdbqf59Gx5I=; h=From:To:Subject:Date:Message-ID:MIME-Version; b=X+k+TuORgITax6OXPqAbRB0HNjLzavaHRZhT6A0kXVWWzfaWQzQd9orTKlr6ssYXb8nODR79IujHVYaaWd8FEa6fyW2sJlNOWik6JKfm19aWYrrNHcJDjEzJ8NgAOzPXMB8V8ZWJ1arw1edVhVik/HDrMToV4Hd1BXvJ4PWuDno= 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=uPo5/0sM; 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="uPo5/0sM" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netfilter.org; s=2025; t=1788390397; bh=7ceelJ4rVhwMztm01TGLWnPXz33hwAMgu0UcfEKaHVM=; h=From:To:Subject:Date:From; b=uPo5/0sMFwNrk9U3InBNbJypYcCecN2+OJPQQku7Q/tbCzM3kVpJOZOqcWYF9tp2S boAqRlgPfk31t1ibSxwmUAZYKudDgyzyZ0VtLr8BskIrROcSJCkTEVEqJdnLQZHwyE 4tRKBQPXbXZkKsXKlpxXzsakXtGJOo8a8JdPzHaE7vLniF2plR0PHRspD5PsHlg4jz 0UWJdrc/kGXGsxq/jov8nhgiOnyHQOcvSTXTs3KVZphIbLz/rsNCqb5+T/39q5jPQP I3cl8vFkOcZLsV9d40EDWV5Vtz+XiQsMTl3VgEFBJ/GkyWbBAr1z29XE8LXOV3uMe2 hk0JXClJXsc+w== Received: from localhost.localdomain (mail-agni [217.70.190.124]) by mail.netfilter.org (Postfix) with ESMTPSA id 31E756085E for ; Thu, 3 Sep 2026 01:06:37 +0200 (CEST) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Subject: [PATCH nf,v2] netfilter: nf_nat: unregister and release hooks on error Date: Thu, 3 Sep 2026 01:06:33 +0200 Message-ID: <20260902230633.1021250-1-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 --- v2: - move common error path handling under goto label - postpone setting nat_proto_net->nat_hook_ops to decide what to do in the error path. net/netfilter/nf_nat_core.c | 43 ++++++++++++++++++++++++------------- 1 file changed, 28 insertions(+), 15 deletions(-) diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c index 8ac326e1eb5b..de1fa53912c2 100644 --- a/net/netfilter/nf_nat_core.c +++ b/net/netfilter/nf_nat_core.c @@ -1224,31 +1224,44 @@ 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; } 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