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 54379248861; Thu, 26 Mar 2026 12:52:10 +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=1774529533; cv=none; b=TCaQgtu7Xq+WbEEd9GXf/A0Ade07MDZGlTY0w6qGvG73o+AHaDPQoocpKcgIX/I/3Kr17IkJ+mBMFMWwlmRvkPWexB/ZrZGmjMyCVinPW8R0M92K51bCzcaFZiP8WBKDph8oiAXncR7QO7SGaYgZpqg59qnQ1wbBzHuM66mxuzc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774529533; c=relaxed/simple; bh=gztqscbUaLD/2uRGb0cq135ZPkvkaCUcDDpyOb7ibUs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LOj7IWyeh2h2zPw+8kEKRgJNynTMoW1uZzY9oXdxyuB5FDS/BRg7T8h63W4pbSBn8WS73ywO8yzpolGgFpv4vdK3/A3zcyU5XNWUs6SCorKy5/Qv4BUK2xM9ev5ic46z9n2Qo/MOdCSTgsoP0GryxE31R59X+8ijp/601Xr8aBw= 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=cFmBQh20; 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="cFmBQh20" Received: from localhost.localdomain (mail-agni [217.70.190.124]) by mail.netfilter.org (Postfix) with ESMTPSA id 2D64660272; Thu, 26 Mar 2026 13:52:08 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netfilter.org; s=2025; t=1774529528; bh=BhmEnl0LM1sg6QQoh5cz1f0Q9H6mjqbhLb5C6npbmUw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cFmBQh20U/ccFahbJj5AWf6V/VcRCXmMgNluks10T6tPObvb/X0ldrirxHvivqWS1 0cZZxYQwMAUvvX22bLwvjTHB+6rP7feIWeEGGd9g6Ha70qsOcAurhX0kgSTzjtFJLH Z2mXxVquXYy9+C09tbQRiIiWMfvwsI01QIgC1P9R8U3l7ft0dnYkwmjQgPLR5xhU+t sMuvHyymPYrOXNDlaAZxu7/9kjcB73y93QDIEQLOO37z6YotNwsaBIhA6V5yWWgpVQ l3URevPpymCSiSBTCYEWha2nYg/R7zf2tn4M5KfQlBqRA2mfxbi+XScfbcQ1KcxVh+ 4QdQmUJRYQlNg== From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com, fw@strlen.de, horms@kernel.org Subject: [PATCH net 09/12] netfilter: nf_conntrack_expect: store netns and zone in expectation Date: Thu, 26 Mar 2026 13:51:50 +0100 Message-ID: <20260326125153.685915-10-pablo@netfilter.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260326125153.685915-1-pablo@netfilter.org> References: <20260326125153.685915-1-pablo@netfilter.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit __nf_ct_expect_find() and nf_ct_expect_find_get() are called under rcu_read_lock() but they dereference the master conntrack via exp->master. Since the expectation does not hold a reference on the master conntrack, this could be dying conntrack or different recycled conntrack than the real master due to SLAB_TYPESAFE_RCU. Store the netns, the master_tuple and the zone in struct nf_conntrack_expect as a safety measure. This patch is required by the follow up fix not to dump expectations that do not belong to this netns. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_conntrack_expect.h | 18 +++++++++++++++++- net/netfilter/nf_conntrack_broadcast.c | 6 +++++- net/netfilter/nf_conntrack_expect.c | 9 +++++++-- net/netfilter/nf_conntrack_netlink.c | 5 +++++ 4 files changed, 34 insertions(+), 4 deletions(-) diff --git a/include/net/netfilter/nf_conntrack_expect.h b/include/net/netfilter/nf_conntrack_expect.h index 1b01400b10bd..e9a8350e7ccf 100644 --- a/include/net/netfilter/nf_conntrack_expect.h +++ b/include/net/netfilter/nf_conntrack_expect.h @@ -22,10 +22,16 @@ struct nf_conntrack_expect { /* Hash member */ struct hlist_node hnode; + /* Network namespace */ + possible_net_t net; + /* We expect this tuple, with the following mask */ struct nf_conntrack_tuple tuple; struct nf_conntrack_tuple_mask mask; +#ifdef CONFIG_NF_CONNTRACK_ZONES + struct nf_conntrack_zone zone; +#endif /* Usage count. */ refcount_t use; @@ -62,7 +68,17 @@ struct nf_conntrack_expect { static inline struct net *nf_ct_exp_net(struct nf_conntrack_expect *exp) { - return nf_ct_net(exp->master); + return read_pnet(&exp->net); +} + +static inline bool nf_ct_exp_zone_equal_any(const struct nf_conntrack_expect *a, + const struct nf_conntrack_zone *b) +{ +#ifdef CONFIG_NF_CONNTRACK_ZONES + return a->zone.id == b->id; +#else + return true; +#endif } #define NF_CT_EXP_POLICY_NAME_LEN 16 diff --git a/net/netfilter/nf_conntrack_broadcast.c b/net/netfilter/nf_conntrack_broadcast.c index 1964c596c646..4f39bf7c843f 100644 --- a/net/netfilter/nf_conntrack_broadcast.c +++ b/net/netfilter/nf_conntrack_broadcast.c @@ -21,6 +21,7 @@ int nf_conntrack_broadcast_help(struct sk_buff *skb, unsigned int timeout) { const struct nf_conntrack_helper *helper; + struct net *net = read_pnet(&ct->ct_net); struct nf_conntrack_expect *exp; struct iphdr *iph = ip_hdr(skb); struct rtable *rt = skb_rtable(skb); @@ -71,7 +72,10 @@ int nf_conntrack_broadcast_help(struct sk_buff *skb, exp->flags = NF_CT_EXPECT_PERMANENT; exp->class = NF_CT_EXPECT_CLASS_DEFAULT; rcu_assign_pointer(exp->helper, helper); - + write_pnet(&exp->net, net); +#ifdef CONFIG_NF_CONNTRACK_ZONES + exp->zone = ct->zone; +#endif nf_ct_expect_related(exp, 0); nf_ct_expect_put(exp); diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c index 1cbe5f1108c2..db28801b1688 100644 --- a/net/netfilter/nf_conntrack_expect.c +++ b/net/netfilter/nf_conntrack_expect.c @@ -113,8 +113,8 @@ nf_ct_exp_equal(const struct nf_conntrack_tuple *tuple, const struct net *net) { return nf_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask) && - net_eq(net, nf_ct_net(i->master)) && - nf_ct_zone_equal_any(i->master, zone); + net_eq(net, read_pnet(&i->net)) && + nf_ct_exp_zone_equal_any(i, zone); } bool nf_ct_remove_expect(struct nf_conntrack_expect *exp) @@ -326,6 +326,7 @@ void nf_ct_expect_init(struct nf_conntrack_expect *exp, unsigned int class, { struct nf_conntrack_helper *helper = NULL; struct nf_conn *ct = exp->master; + struct net *net = read_pnet(&ct->ct_net); struct nf_conn_help *help; int len; @@ -343,6 +344,10 @@ void nf_ct_expect_init(struct nf_conntrack_expect *exp, unsigned int class, helper = rcu_dereference(help->helper); rcu_assign_pointer(exp->helper, helper); + write_pnet(&exp->net, net); +#ifdef CONFIG_NF_CONNTRACK_ZONES + exp->zone = ct->zone; +#endif exp->tuple.src.l3num = family; exp->tuple.dst.protonum = proto; diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 89540112d165..6e6aeb0ab0a1 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -3538,6 +3538,7 @@ ctnetlink_alloc_expect(const struct nlattr * const cda[], struct nf_conn *ct, struct nf_conntrack_tuple *tuple, struct nf_conntrack_tuple *mask) { + struct net *net = read_pnet(&ct->ct_net); struct nf_conntrack_expect *exp; struct nf_conn_help *help; u32 class = 0; @@ -3577,6 +3578,10 @@ ctnetlink_alloc_expect(const struct nlattr * const cda[], struct nf_conn *ct, exp->class = class; exp->master = ct; + write_pnet(&exp->net, net); +#ifdef CONFIG_NF_CONNTRACK_ZONES + exp->zone = ct->zone; +#endif if (!helper) helper = rcu_dereference(help->helper); rcu_assign_pointer(exp->helper, helper); -- 2.47.3