From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 10F22C636F3 for ; Tue, 21 Nov 2023 12:13:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234714AbjKUMN7 (ORCPT ); Tue, 21 Nov 2023 07:13:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36090 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234715AbjKUMN6 (ORCPT ); Tue, 21 Nov 2023 07:13:58 -0500 Received: from mail.netfilter.org (mail.netfilter.org [217.70.188.207]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id D8BC912C; Tue, 21 Nov 2023 04:13:53 -0800 (PST) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: gregkh@linuxfoundation.org, sashal@kernel.org, stable@vger.kernel.org Subject: [PATCH -stable,5.4 22/26] netfilter: nf_tables: double hook unregistration in netns path Date: Tue, 21 Nov 2023 13:13:29 +0100 Message-Id: <20231121121333.294238-23-pablo@netfilter.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20231121121333.294238-1-pablo@netfilter.org> References: <20231121121333.294238-1-pablo@netfilter.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org commit f9a43007d3f7ba76d5e7f9421094f00f2ef202f8 upstream. __nft_release_hooks() is called from pre_netns exit path which unregisters the hooks, then the NETDEV_UNREGISTER event is triggered which unregisters the hooks again. [ 565.221461] WARNING: CPU: 18 PID: 193 at net/netfilter/core.c:495 __nf_unregister_net_hook+0x247/0x270 [...] [ 565.246890] CPU: 18 PID: 193 Comm: kworker/u64:1 Tainted: G E 5.18.0-rc7+ #27 [ 565.253682] Workqueue: netns cleanup_net [ 565.257059] RIP: 0010:__nf_unregister_net_hook+0x247/0x270 [...] [ 565.297120] Call Trace: [ 565.300900] [ 565.304683] nf_tables_flowtable_event+0x16a/0x220 [nf_tables] [ 565.308518] raw_notifier_call_chain+0x63/0x80 [ 565.312386] unregister_netdevice_many+0x54f/0xb50 Unregister and destroy netdev hook from netns pre_exit via kfree_rcu so the NETDEV_UNREGISTER path see unregistered hooks. Fixes: 767d1216bff8 ("netfilter: nftables: fix possible UAF over chains from packet path in netns") Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 34 +++++++++++++++++++++++++------- net/netfilter/nft_chain_filter.c | 3 +++ 2 files changed, 30 insertions(+), 7 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index cdb1862d6588..afa7aebf75ef 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -219,9 +219,10 @@ static int nf_tables_register_hook(struct net *net, return nf_register_net_hook(net, ops); } -static void nf_tables_unregister_hook(struct net *net, - const struct nft_table *table, - struct nft_chain *chain) +static void __nf_tables_unregister_hook(struct net *net, + const struct nft_table *table, + struct nft_chain *chain, + bool release_netdev) { const struct nft_base_chain *basechain; const struct nf_hook_ops *ops; @@ -236,6 +237,16 @@ static void nf_tables_unregister_hook(struct net *net, return basechain->type->ops_unregister(net, ops); nf_unregister_net_hook(net, ops); + if (release_netdev && + table->family == NFPROTO_NETDEV) + nft_base_chain(chain)->ops.dev = NULL; +} + +static void nf_tables_unregister_hook(struct net *net, + const struct nft_table *table, + struct nft_chain *chain) +{ + __nf_tables_unregister_hook(net, table, chain, false); } static int nft_trans_table_add(struct nft_ctx *ctx, int msg_type) @@ -5997,8 +6008,9 @@ nft_flowtable_type_get(struct net *net, u8 family) return ERR_PTR(-ENOENT); } -static void nft_unregister_flowtable_net_hooks(struct net *net, - struct nft_flowtable *flowtable) +static void __nft_unregister_flowtable_net_hooks(struct net *net, + struct nft_flowtable *flowtable, + bool release_netdev) { int i; @@ -6007,9 +6019,17 @@ static void nft_unregister_flowtable_net_hooks(struct net *net, continue; nf_unregister_net_hook(net, &flowtable->ops[i]); + if (release_netdev) + flowtable->ops[i].dev = NULL; } } +static void nft_unregister_flowtable_net_hooks(struct net *net, + struct nft_flowtable *flowtable) +{ + __nft_unregister_flowtable_net_hooks(net, flowtable, false); +} + static int nf_tables_newflowtable(struct net *net, struct sock *nlsk, struct sk_buff *skb, const struct nlmsghdr *nlh, @@ -8192,9 +8212,9 @@ static void __nft_release_hook(struct net *net, struct nft_table *table) struct nft_chain *chain; list_for_each_entry(chain, &table->chains, list) - nf_tables_unregister_hook(net, table, chain); + __nf_tables_unregister_hook(net, table, chain, true); list_for_each_entry(flowtable, &table->flowtables, list) - nft_unregister_flowtable_net_hooks(net, flowtable); + __nft_unregister_flowtable_net_hooks(net, flowtable, true); } static void __nft_release_hooks(struct net *net) diff --git a/net/netfilter/nft_chain_filter.c b/net/netfilter/nft_chain_filter.c index 04824d7dcc22..916195dba6f7 100644 --- a/net/netfilter/nft_chain_filter.c +++ b/net/netfilter/nft_chain_filter.c @@ -296,6 +296,9 @@ static void nft_netdev_event(unsigned long event, struct net_device *dev, if (strcmp(basechain->dev_name, dev->name) != 0) return; + if (!basechain->ops.dev) + return; + /* UNREGISTER events are also happpening on netns exit. * * Altough nf_tables core releases all tables/chains, only -- 2.30.2