From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 1731B332637; Tue, 16 Jun 2026 16:59:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781629170; cv=none; b=cCMDtlF7g8/2cMjg4dOyJKiuNnJQGRCD2enHQA1raiAiOeoRQF06vlW/JPD8NydWqRCaA82SL5TLjq5w9cT4AlTV/Zyq2h6NTd7M5RtpMEvfZQWUw4BcomP4GlmNP9V1UYfa2pJW+qCChuT/JPy3IGjhliUQJzywnNyxPIKGKEg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781629170; c=relaxed/simple; bh=foVc5cCNAJFaURks3knyzd4asg2qubEfgupWf1FoKZ8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=g3CdOePwMa2viLCPp2OkUu/ijNooEGaPtoLmymaxylIY9UUKQ3ouLmAMFgU1Kdz2iE7MteibA8pr3psi1H7NDlro3CvgDcsThODw/EKOgYQfmk/bpGM62ZFAI3JEXfFaxlUndWT+mItuPK5Z8wlkEZJ81VpuOcWBDwrMRqHU/co= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=sXJGF6an; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="sXJGF6an" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BD6B11F000E9; Tue, 16 Jun 2026 16:59:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781629168; bh=BtCK9ylNcvZDKypGyRTAPrkXCl0Z9xCO+vCultGwdUU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=sXJGF6anymmBzNmsHKeSAkTRIDGDonh2ikxDhp4rZSXiEzjvc2ZeRnlSanDZ8IM9Y YcYSuw0vO1dUaMGAnc9hzMtBgqiqkomi4XzIudjwADNNj9E7CDPUrNkNnp+mOBoQYK zqevos7STqp5ULSNdIhsnauGRK1Rk1k///xeBDvQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Fernando Fernandez Mancera , Florian Westphal , Pablo Neira Ayuso , Sasha Levin Subject: [PATCH 6.6 217/452] netfilter: synproxy: add mutex to guard hook reference counting Date: Tue, 16 Jun 2026 20:27:24 +0530 Message-ID: <20260616145129.186402376@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260616145117.796205997@linuxfoundation.org> References: <20260616145117.796205997@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Fernando Fernandez Mancera [ Upstream commit 2fcba19caaeb2a33017459d3430f057967bb91b6 ] As the synproxy infrastructure register netfilter hooks on-demand when a user adds the first iptables target or nftables expression, if done concurrently they can race each other. Introduce a mutex to serialize the refcount control blocks access from both frontends. While a per namespace mutex might be more efficient, it is not needed for target/expression like SYNPROXY. Fixes: ad49d86e07a4 ("netfilter: nf_tables: Add synproxy support") Signed-off-by: Fernando Fernandez Mancera Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- net/netfilter/nf_synproxy_core.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/net/netfilter/nf_synproxy_core.c b/net/netfilter/nf_synproxy_core.c index f5a52075691faa..500a90311ed505 100644 --- a/net/netfilter/nf_synproxy_core.c +++ b/net/netfilter/nf_synproxy_core.c @@ -21,6 +21,8 @@ #include #include +static DEFINE_MUTEX(synproxy_mutex); + unsigned int synproxy_net_id; EXPORT_SYMBOL_GPL(synproxy_net_id); @@ -768,26 +770,31 @@ static const struct nf_hook_ops ipv4_synproxy_ops[] = { int nf_synproxy_ipv4_init(struct synproxy_net *snet, struct net *net) { - int err; + int err = 0; + mutex_lock(&synproxy_mutex); if (snet->hook_ref4 == 0) { err = nf_register_net_hooks(net, ipv4_synproxy_ops, ARRAY_SIZE(ipv4_synproxy_ops)); if (err) - return err; + goto out; } snet->hook_ref4++; - return 0; +out: + mutex_unlock(&synproxy_mutex); + return err; } EXPORT_SYMBOL_GPL(nf_synproxy_ipv4_init); void nf_synproxy_ipv4_fini(struct synproxy_net *snet, struct net *net) { + mutex_lock(&synproxy_mutex); snet->hook_ref4--; if (snet->hook_ref4 == 0) nf_unregister_net_hooks(net, ipv4_synproxy_ops, ARRAY_SIZE(ipv4_synproxy_ops)); + mutex_unlock(&synproxy_mutex); } EXPORT_SYMBOL_GPL(nf_synproxy_ipv4_fini); @@ -1192,27 +1199,32 @@ static const struct nf_hook_ops ipv6_synproxy_ops[] = { int nf_synproxy_ipv6_init(struct synproxy_net *snet, struct net *net) { - int err; + int err = 0; + mutex_lock(&synproxy_mutex); if (snet->hook_ref6 == 0) { err = nf_register_net_hooks(net, ipv6_synproxy_ops, ARRAY_SIZE(ipv6_synproxy_ops)); if (err) - return err; + goto out; } snet->hook_ref6++; - return 0; +out: + mutex_unlock(&synproxy_mutex); + return err; } EXPORT_SYMBOL_GPL(nf_synproxy_ipv6_init); void nf_synproxy_ipv6_fini(struct synproxy_net *snet, struct net *net) { + mutex_lock(&synproxy_mutex); snet->hook_ref6--; if (snet->hook_ref6 == 0) nf_unregister_net_hooks(net, ipv6_synproxy_ops, ARRAY_SIZE(ipv6_synproxy_ops)); + mutex_unlock(&synproxy_mutex); } EXPORT_SYMBOL_GPL(nf_synproxy_ipv6_fini); #endif /* CONFIG_IPV6 */ -- 2.53.0