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 27C1B3C4161; Tue, 23 Jun 2026 22:16:01 +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=1782252964; cv=none; b=gZdsfT7uvP9nXCS2WoiCUKPJAqlim1pPEys8m++N/BSl95BsHK79OdVZWFLsQNX3TixvdhOUT5buZfKvF3GrAJBVvjc4MKyZG5OSqFixX0h5xP7F5mGU+t9Nnojs+ueDuVtRPaxv0AY7xktf/D9v04j3NMppDDWv+4kesilV3tM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782252964; c=relaxed/simple; bh=kkdBNEJleQ+EwIARmcpo3tE5v85znoksQjLuW+D8jlU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=T3H0zGwbKGq2gznuHYLiuQmPUL3pKCt9lDu3Pp2OQGNe0f3zoVI475T7l+dPaD+3hW5i6slKybJ/Cg3NE3rGq1VXiBFKK7n59N7kHpjU/dxKwMM5XkqaXFBmq/fR52RYZH2rHrvT5nda1kSyq5MkER/cT+oDVXXB4spsu9rrWlA= 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=lnxH+VaU; 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="lnxH+VaU" Received: from localhost.localdomain (mail-agni [217.70.190.124]) by mail.netfilter.org (Postfix) with ESMTPSA id 283966057B; Wed, 24 Jun 2026 00:15:59 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netfilter.org; s=2025; t=1782252959; bh=71QmhRBsKjYPgcwSQ/V44nlkTJN0AjYuPmOrQoHzd54=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lnxH+VaU6dXtOQvhCmpPMi/m1yQmQOLNee6yjRkPNRpaUaaftwHj6ZZBXWs/6jFlw wS1xv+Z2LCz3puryCwjgKSEgFIMeTiFoo1h+sw36MZP56/HtQ7xrySkKmPJbUnuaV4 QIOI71QUQ4sTzxGbYYO/vedggKnGta0GsoE/Os1IHmykyC1M1WcGoOF9EvYC1Jl6jB r+rcHPKBfUwsfjKTSw0PjCwD6wDwoUKsOr15pUSsdIqg2aW2fAkknke3fq7ILF1xXn lPkdJncXwVBGPJrCSE/66Jh24KkvEic9SdUGC7TXQG4CtYnkptpLKAE22MNeHAHmUD 8Fcj2kr6EMkeA== 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 05/14] netfilter: nft_synproxy: stop bypassing the priv->info snapshot Date: Wed, 24 Jun 2026 00:15:38 +0200 Message-ID: <20260623221548.701545-6-pablo@netfilter.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260623221548.701545-1-pablo@netfilter.org> References: <20260623221548.701545-1-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 From: Runyu Xiao nft_synproxy_eval_v4() and nft_synproxy_eval_v6() already take a whole-object READ_ONCE() snapshot of the shared priv->info state before building the SYNACK reply, but nft_synproxy_tcp_options() still masks opts->options with priv->info.options from the live shared object. When a named synproxy object is updated concurrently with SYN traffic, the eval path can then mix mss and timestamp handling from the local snapshot with an options mask taken from a newer configuration, so one SYNACK no longer reflects a coherent synproxy configuration. Use info->options so nft_synproxy_tcp_options() stays on the same local snapshot that the eval path already copied from priv->info. Fixes: ee394f96ad75 ("netfilter: nft_synproxy: add synproxy stateful object support") Signed-off-by: Runyu Xiao Reviewed-by: Fernando Fernandez Mancera Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_synproxy.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/net/netfilter/nft_synproxy.c b/net/netfilter/nft_synproxy.c index 7641f249614c..9ed288c9d168 100644 --- a/net/netfilter/nft_synproxy.c +++ b/net/netfilter/nft_synproxy.c @@ -24,14 +24,13 @@ static const struct nla_policy nft_synproxy_policy[NFTA_SYNPROXY_MAX + 1] = { static void nft_synproxy_tcp_options(struct synproxy_options *opts, const struct tcphdr *tcp, struct synproxy_net *snet, - struct nf_synproxy_info *info, - const struct nft_synproxy *priv) + struct nf_synproxy_info *info) { this_cpu_inc(snet->stats->syn_received); if (tcp->ece && tcp->cwr) opts->options |= NF_SYNPROXY_OPT_ECN; - opts->options &= priv->info.options; + opts->options &= info->options; opts->mss_encode = opts->mss_option; opts->mss_option = info->mss; if (opts->options & NF_SYNPROXY_OPT_TIMESTAMP) @@ -56,7 +55,7 @@ static void nft_synproxy_eval_v4(const struct nft_synproxy *priv, if (tcp->syn) { /* Initial SYN from client */ - nft_synproxy_tcp_options(opts, tcp, snet, &info, priv); + nft_synproxy_tcp_options(opts, tcp, snet, &info); synproxy_send_client_synack(net, skb, tcp, opts); consume_skb(skb); regs->verdict.code = NF_STOLEN; @@ -87,7 +86,7 @@ static void nft_synproxy_eval_v6(const struct nft_synproxy *priv, if (tcp->syn) { /* Initial SYN from client */ - nft_synproxy_tcp_options(opts, tcp, snet, &info, priv); + nft_synproxy_tcp_options(opts, tcp, snet, &info); synproxy_send_client_synack_ipv6(net, skb, tcp, opts); consume_skb(skb); regs->verdict.code = NF_STOLEN; -- 2.47.3