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 306F23B6359; Sat, 30 May 2026 17:39:11 +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=1780162753; cv=none; b=SinE2oIe2JwUMZZnCQc3dRvbIHTBxL1U6VftblbOl+aa0gRxuRUpJgPQca48XYRngw/50Ydk1gZQ7xHZzjTy0ZRhwK+rLMr24Wb00OWIaU6VMHD303mtse1j/3gaUZBX10xm4MZwaYqI7LnN7kxgaECSNOCXQVz5SkJuENXheLQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780162753; c=relaxed/simple; bh=iTWjfo8ZUCJSJWnPVpA63wOOt+YRETywmvAzaP3GUAE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=I383HhN+k4yQMg03iXi8iY8C59iJ7m6bVb/GiaQA9bzvqruuock7zrB0uq5ZSVWcbefiVCMuGrfbFF7naIelhmqO7F//7hyrBN8XeCfsSbfqIPhq1mkGL5p3E3Q230mAdlikRxksRnmX7gcldh+sA9WPHbBnA0CJXtl1JB5Ws0I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=1VCunKts; 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="1VCunKts" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3F0CA1F00893; Sat, 30 May 2026 17:39:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780162750; bh=hdz0vCWMaUSAbpH0n13nJG+OGyeDNHukItoSH1oKpgE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=1VCunKtsohinMFw6fS3O1KIIsG0NotuEoQPtGHnCy3Cekm5+2VDwNuf8E3zzZcYR+ XcOm5133hnofdMlbUto4DsFXgd6e11EJqE7PCIgtXWSqRcYXwq+lZOatN1odmvs/Y6 JMpDifAhM1pAAOiegWgqasnLciHH5SXkpj1XtiFI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yifan Wu , Juefei Pu , Yuan Tan , Xin Liu , Yuhang Zheng , Ren Wei , Florian Westphal , Sasha Levin Subject: [PATCH 5.15 035/776] netfilter: xt_multiport: validate range encoding in checkentry Date: Sat, 30 May 2026 17:55:49 +0200 Message-ID: <20260530160241.191010797@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160240.228940103@linuxfoundation.org> References: <20260530160240.228940103@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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ren Wei [ Upstream commit ff64c5bfef12461df8450e0f50bb693b5269c720 ] ports_match_v1() treats any non-zero pflags entry as the start of a port range and unconditionally consumes the next ports[] element as the range end. The checkentry path currently validates protocol, flags and count, but it does not validate the range encoding itself. As a result, malformed rules can mark the last slot as a range start or place two range starts back to back, leaving ports_match_v1() to step past the last valid ports[] element while interpreting the rule. Reject malformed multiport v1 rules in checkentry by validating that each range start has a following element and that the following element is not itself marked as another range start. Fixes: a89ecb6a2ef7 ("[NETFILTER]: x_tables: unify IPv4/IPv6 multiport match") Reported-by: Yifan Wu Reported-by: Juefei Pu Co-developed-by: Yuan Tan Signed-off-by: Yuan Tan Suggested-by: Xin Liu Tested-by: Yuhang Zheng Signed-off-by: Ren Wei Signed-off-by: Florian Westphal Signed-off-by: Sasha Levin --- net/netfilter/xt_multiport.c | 34 ++++++++++++++++++++++++++++++---- 1 file changed, 30 insertions(+), 4 deletions(-) diff --git a/net/netfilter/xt_multiport.c b/net/netfilter/xt_multiport.c index 44a00f5acde8a..a1691ff405d3c 100644 --- a/net/netfilter/xt_multiport.c +++ b/net/netfilter/xt_multiport.c @@ -105,6 +105,28 @@ multiport_mt(const struct sk_buff *skb, struct xt_action_param *par) return ports_match_v1(multiinfo, ntohs(pptr[0]), ntohs(pptr[1])); } +static bool +multiport_valid_ranges(const struct xt_multiport_v1 *multiinfo) +{ + unsigned int i; + + for (i = 0; i < multiinfo->count; i++) { + if (!multiinfo->pflags[i]) + continue; + + if (++i >= multiinfo->count) + return false; + + if (multiinfo->pflags[i]) + return false; + + if (multiinfo->ports[i - 1] > multiinfo->ports[i]) + return false; + } + + return true; +} + static inline bool check(u_int16_t proto, u_int8_t ip_invflags, @@ -127,8 +149,10 @@ static int multiport_mt_check(const struct xt_mtchk_param *par) const struct ipt_ip *ip = par->entryinfo; const struct xt_multiport_v1 *multiinfo = par->matchinfo; - return check(ip->proto, ip->invflags, multiinfo->flags, - multiinfo->count) ? 0 : -EINVAL; + if (!check(ip->proto, ip->invflags, multiinfo->flags, multiinfo->count)) + return -EINVAL; + + return multiport_valid_ranges(multiinfo) ? 0 : -EINVAL; } static int multiport_mt6_check(const struct xt_mtchk_param *par) @@ -136,8 +160,10 @@ static int multiport_mt6_check(const struct xt_mtchk_param *par) const struct ip6t_ip6 *ip = par->entryinfo; const struct xt_multiport_v1 *multiinfo = par->matchinfo; - return check(ip->proto, ip->invflags, multiinfo->flags, - multiinfo->count) ? 0 : -EINVAL; + if (!check(ip->proto, ip->invflags, multiinfo->flags, multiinfo->count)) + return -EINVAL; + + return multiport_valid_ranges(multiinfo) ? 0 : -EINVAL; } static struct xt_match multiport_mt_reg[] __read_mostly = { -- 2.53.0