{"id":2233360,"url":"http://patchwork.ozlabs.org/api/1.1/patches/2233360/?format=json","web_url":"http://patchwork.ozlabs.org/project/netfilter-devel/patch/20260506100728.2664-7-fw@strlen.de/","project":{"id":26,"url":"http://patchwork.ozlabs.org/api/1.1/projects/26/?format=json","name":"Netfilter Development","link_name":"netfilter-devel","list_id":"netfilter-devel.vger.kernel.org","list_email":"netfilter-devel@vger.kernel.org","web_url":null,"scm_url":null,"webscm_url":null},"msgid":"<20260506100728.2664-7-fw@strlen.de>","date":"2026-05-06T10:07:18","name":"[v3,nf,6/8] netfilter: ebtables: move to two-stage removal scheme","commit_ref":null,"pull_url":null,"state":"accepted","archived":false,"hash":"04b9cefc764a50d99f245c0bee7f73e5460390d7","submitter":{"id":1025,"url":"http://patchwork.ozlabs.org/api/1.1/people/1025/?format=json","name":"Florian Westphal","email":"fw@strlen.de"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/netfilter-devel/patch/20260506100728.2664-7-fw@strlen.de/mbox/","series":[{"id":502948,"url":"http://patchwork.ozlabs.org/api/1.1/series/502948/?format=json","web_url":"http://patchwork.ozlabs.org/project/netfilter-devel/list/?series=502948","date":"2026-05-06T10:07:14","name":"netfilter: xtables: fix module load and teardown races","version":3,"mbox":"http://patchwork.ozlabs.org/series/502948/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2233360/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2233360/checks/","tags":{},"headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","netfilter-devel@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c0a:e001:db::12fc:5321; helo=sea.lore.kernel.org;\n envelope-from=netfilter-devel+bounces-12457-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=91.216.245.30","smtp.subspace.kernel.org;\n dmarc=none (p=none dis=none) header.from=strlen.de","smtp.subspace.kernel.org;\n spf=pass smtp.mailfrom=Chamillionaire.breakpoint.cc"],"Received":["from sea.lore.kernel.org (sea.lore.kernel.org\n [IPv6:2600:3c0a:e001:db::12fc:5321])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4g9WKl69FSz1yJx\n\tfor ; Wed, 06 May 2026 20:08:11 +1000 (AEST)","from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby sea.lore.kernel.org (Postfix) with ESMTP id 2CE193005786\n\tfor ; Wed, 6 May 2026 10:08:07 +0000 (UTC)","from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id 4494A3FB7DC;\n\tWed, 6 May 2026 10:08:06 +0000 (UTC)","from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc\n [91.216.245.30])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby smtp.subspace.kernel.org (Postfix) with ESMTPS id 6C43F3ECBEA\n\tfor ; Wed, 6 May 2026 10:08:02 +0000 (UTC)","by Chamillionaire.breakpoint.cc (Postfix, from userid 1003)\n\tid 1A2FF605F3; Wed, 06 May 2026 12:08:00 +0200 (CEST)"],"ARC-Seal":"i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1778062085; cv=none;\n b=LbrRR5DqHP5TE2NzbI5HmLUhCVtadPujc66RLhNB2XzhOrys+j6sMdP1bRtpaTlIuaeotj5iSPVgWWiBWm0kwkQU2bAV71HeyaKDLg7MX6P6m7ywqveYD1SasxBuY7KpMhiRmwU5A4oS71ff33lR7R6NrilQdLdGIXg030EZ3DA=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1778062085; c=relaxed/simple;\n\tbh=u23QBFBOTjMmSlMiAS88JjVKwoeAmMETJ7X8GdcZIzM=;\n\th=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References:\n\t MIME-Version;\n b=lr/Zb6MEoELY5zUTFMWt3L2ucAYg2WRmrmlO7wDU91blZbOmkZISgaG7EpQonPaHHtjDblRaNjpf3CO5E5BTvIn4t2M21Cj2D5utVZQy6L50Rla5sSxRG/vsbClfODJ7Z9ZLc3roPerfegka1+33gB1HrGw8aUiSQddY5HYZzEI=","ARC-Authentication-Results":"i=1; smtp.subspace.kernel.org;\n dmarc=none (p=none dis=none) header.from=strlen.de;\n spf=pass smtp.mailfrom=Chamillionaire.breakpoint.cc;\n arc=none smtp.client-ip=91.216.245.30","From":"Florian Westphal ","To":"","Cc":"tristan@talencesecurity.com,\n\tFlorian Westphal ","Subject":"[PATCH v3 nf 6/8] netfilter: ebtables: move to two-stage removal\n scheme","Date":"Wed, 6 May 2026 12:07:18 +0200","Message-ID":"<20260506100728.2664-7-fw@strlen.de>","X-Mailer":"git-send-email 2.53.0","In-Reply-To":"<20260506100728.2664-1-fw@strlen.de>","References":"<20260506100728.2664-1-fw@strlen.de>","Precedence":"bulk","X-Mailing-List":"netfilter-devel@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit"},"content":"Like previous patches for x_tables, follow same pattern in ebtables.\nWe can't reuse xt helpers: ebt_table struct layout is incompatible.\n\ntable->ops assignment is now done while still holding the ebt mutex\nto make sure we never expose partially-filled table struct.\n\nFixes: 87663c39f898 (\"netfilter: ebtables: do not hook tables by default\")\nReviewed-by: Tristan Madani \nSigned-off-by: Florian Westphal \n---\n v3: also reorder in ebtable_filter fini.\n net/bridge/netfilter/ebtable_broute.c | 2 +-\n net/bridge/netfilter/ebtable_filter.c | 2 +-\n net/bridge/netfilter/ebtable_nat.c | 2 +-\n net/bridge/netfilter/ebtables.c | 60 +++++++++++++++++----------\n 4 files changed, 40 insertions(+), 26 deletions(-)","diff":"diff --git a/net/bridge/netfilter/ebtable_broute.c b/net/bridge/netfilter/ebtable_broute.c\nindex 741360219552..e6f9e343b41f 100644\n--- a/net/bridge/netfilter/ebtable_broute.c\n+++ b/net/bridge/netfilter/ebtable_broute.c\n@@ -128,8 +128,8 @@ static int __init ebtable_broute_init(void)\n \n static void __exit ebtable_broute_fini(void)\n {\n-\tunregister_pernet_subsys(&broute_net_ops);\n \tebt_unregister_template(&broute_table);\n+\tunregister_pernet_subsys(&broute_net_ops);\n }\n \n module_init(ebtable_broute_init);\ndiff --git a/net/bridge/netfilter/ebtable_filter.c b/net/bridge/netfilter/ebtable_filter.c\nindex dacd81b12e62..02b6501c15a5 100644\n--- a/net/bridge/netfilter/ebtable_filter.c\n+++ b/net/bridge/netfilter/ebtable_filter.c\n@@ -109,8 +109,8 @@ static int __init ebtable_filter_init(void)\n \n static void __exit ebtable_filter_fini(void)\n {\n-\tunregister_pernet_subsys(&frame_filter_net_ops);\n \tebt_unregister_template(&frame_filter);\n+\tunregister_pernet_subsys(&frame_filter_net_ops);\n }\n \n module_init(ebtable_filter_init);\ndiff --git a/net/bridge/netfilter/ebtable_nat.c b/net/bridge/netfilter/ebtable_nat.c\nindex 0f2a8c6118d4..9985a82555c4 100644\n--- a/net/bridge/netfilter/ebtable_nat.c\n+++ b/net/bridge/netfilter/ebtable_nat.c\n@@ -109,8 +109,8 @@ static int __init ebtable_nat_init(void)\n \n static void __exit ebtable_nat_fini(void)\n {\n-\tunregister_pernet_subsys(&frame_nat_net_ops);\n \tebt_unregister_template(&frame_nat);\n+\tunregister_pernet_subsys(&frame_nat_net_ops);\n }\n \n module_init(ebtable_nat_init);\ndiff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c\nindex aea3e19875c6..3578ffbc14ae 100644\n--- a/net/bridge/netfilter/ebtables.c\n+++ b/net/bridge/netfilter/ebtables.c\n@@ -42,6 +42,7 @@\n \n struct ebt_pernet {\n \tstruct list_head tables;\n+\tstruct list_head dead_tables;\n };\n \n struct ebt_template {\n@@ -1162,11 +1163,6 @@ static int do_replace(struct net *net, sockptr_t arg, unsigned int len)\n \n static void __ebt_unregister_table(struct net *net, struct ebt_table *table)\n {\n-\tmutex_lock(&ebt_mutex);\n-\tlist_del(&table->list);\n-\tmutex_unlock(&ebt_mutex);\n-\taudit_log_nfcfg(table->name, AF_BRIDGE, table->private->nentries,\n-\t\t\tAUDIT_XT_OP_UNREGISTER, GFP_KERNEL);\n \tEBT_ENTRY_ITERATE(table->private->entries, table->private->entries_size,\n \t\t\t ebt_cleanup_entry, net, NULL);\n \tif (table->private->nentries)\n@@ -1267,13 +1263,15 @@ int ebt_register_table(struct net *net, const struct ebt_table *input_table,\n \tfor (i = 0; i < num_ops; i++)\n \t\tops[i].priv = table;\n \n-\tlist_add(&table->list, &ebt_net->tables);\n-\tmutex_unlock(&ebt_mutex);\n-\n \ttable->ops = ops;\n \tret = nf_register_net_hooks(net, ops, num_ops);\n-\tif (ret)\n+\tif (ret) {\n+\t\tsynchronize_rcu();\n \t\t__ebt_unregister_table(net, table);\n+\t} else {\n+\t\tlist_add(&table->list, &ebt_net->tables);\n+\t}\n+\tmutex_unlock(&ebt_mutex);\n \n \taudit_log_nfcfg(repl->name, AF_BRIDGE, repl->nentries,\n \t\t\tAUDIT_XT_OP_REGISTER, GFP_KERNEL);\n@@ -1339,7 +1337,7 @@ void ebt_unregister_template(const struct ebt_table *t)\n }\n EXPORT_SYMBOL(ebt_unregister_template);\n \n-static struct ebt_table *__ebt_find_table(struct net *net, const char *name)\n+void ebt_unregister_table_pre_exit(struct net *net, const char *name)\n {\n \tstruct ebt_pernet *ebt_net = net_generic(net, ebt_pernet_id);\n \tstruct ebt_table *t;\n@@ -1348,30 +1346,36 @@ static struct ebt_table *__ebt_find_table(struct net *net, const char *name)\n \n \tlist_for_each_entry(t, &ebt_net->tables, list) {\n \t\tif (strcmp(t->name, name) == 0) {\n+\t\t\tlist_move(&t->list, &ebt_net->dead_tables);\n \t\t\tmutex_unlock(&ebt_mutex);\n-\t\t\treturn t;\n+\t\t\tnf_unregister_net_hooks(net, t->ops, hweight32(t->valid_hooks));\n+\t\t\treturn;\n \t\t}\n \t}\n \n \tmutex_unlock(&ebt_mutex);\n-\treturn NULL;\n-}\n-\n-void ebt_unregister_table_pre_exit(struct net *net, const char *name)\n-{\n-\tstruct ebt_table *table = __ebt_find_table(net, name);\n-\n-\tif (table)\n-\t\tnf_unregister_net_hooks(net, table->ops, hweight32(table->valid_hooks));\n }\n EXPORT_SYMBOL(ebt_unregister_table_pre_exit);\n \n void ebt_unregister_table(struct net *net, const char *name)\n {\n-\tstruct ebt_table *table = __ebt_find_table(net, name);\n+\tstruct ebt_pernet *ebt_net = net_generic(net, ebt_pernet_id);\n+\tstruct ebt_table *t;\n \n-\tif (table)\n-\t\t__ebt_unregister_table(net, table);\n+\tmutex_lock(&ebt_mutex);\n+\n+\tlist_for_each_entry(t, &ebt_net->dead_tables, list) {\n+\t\tif (strcmp(t->name, name) == 0) {\n+\t\t\tlist_del(&t->list);\n+\t\t\taudit_log_nfcfg(t->name, AF_BRIDGE, t->private->nentries,\n+\t\t\t\t\tAUDIT_XT_OP_UNREGISTER, GFP_KERNEL);\n+\t\t\t__ebt_unregister_table(net, t);\n+\t\t\tmutex_unlock(&ebt_mutex);\n+\t\t\treturn;\n+\t\t}\n+\t}\n+\n+\tmutex_unlock(&ebt_mutex);\n }\n \n /* userspace just supplied us with counters */\n@@ -2556,11 +2560,21 @@ static int __net_init ebt_pernet_init(struct net *net)\n \tstruct ebt_pernet *ebt_net = net_generic(net, ebt_pernet_id);\n \n \tINIT_LIST_HEAD(&ebt_net->tables);\n+\tINIT_LIST_HEAD(&ebt_net->dead_tables);\n \treturn 0;\n }\n \n+static void __net_exit ebt_pernet_exit(struct net *net)\n+{\n+\tstruct ebt_pernet *ebt_net = net_generic(net, ebt_pernet_id);\n+\n+\tWARN_ON_ONCE(!list_empty(&ebt_net->tables));\n+\tWARN_ON_ONCE(!list_empty(&ebt_net->dead_tables));\n+}\n+\n static struct pernet_operations ebt_net_ops = {\n \t.init = ebt_pernet_init,\n+\t.exit = ebt_pernet_exit,\n \t.id = &ebt_pernet_id,\n \t.size = sizeof(struct ebt_pernet),\n };\n","prefixes":["v3","nf","6/8"]}