{"id":2220994,"url":"http://patchwork.ozlabs.org/api/1.1/patches/2220994/?format=json","web_url":"http://patchwork.ozlabs.org/project/netfilter-devel/patch/20260408163512.30537-4-fw@strlen.de/","project":{"id":26,"url":"http://patchwork.ozlabs.org/api/1.1/projects/26/?format=json","name":"Netfilter Development","link_name":"netfilter-devel","list_id":"netfilter-devel.vger.kernel.org","list_email":"netfilter-devel@vger.kernel.org","web_url":null,"scm_url":null,"webscm_url":null},"msgid":"<20260408163512.30537-4-fw@strlen.de>","date":"2026-04-08T16:35:08","name":"[net,3/7] netfilter: xt_multiport: validate range encoding in checkentry","commit_ref":null,"pull_url":null,"state":"accepted","archived":true,"hash":"841ac7d8093445506efe70f89ec81158dd61ce16","submitter":{"id":1025,"url":"http://patchwork.ozlabs.org/api/1.1/people/1025/?format=json","name":"Florian Westphal","email":"fw@strlen.de"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/netfilter-devel/patch/20260408163512.30537-4-fw@strlen.de/mbox/","series":[{"id":499159,"url":"http://patchwork.ozlabs.org/api/1.1/series/499159/?format=json","web_url":"http://patchwork.ozlabs.org/project/netfilter-devel/list/?series=499159","date":"2026-04-08T16:35:05","name":"[net,1/7] ipvs: fix NULL deref in ip_vs_add_service error path","version":1,"mbox":"http://patchwork.ozlabs.org/series/499159/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2220994/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2220994/checks/","tags":{},"headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","netfilter-devel@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c0a:e001:db::12fc:5321; helo=sea.lore.kernel.org;\n envelope-from=netfilter-devel+bounces-11741-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=91.216.245.30","smtp.subspace.kernel.org;\n dmarc=none (p=none dis=none) header.from=strlen.de","smtp.subspace.kernel.org;\n spf=pass smtp.mailfrom=Chamillionaire.breakpoint.cc"],"Received":["from sea.lore.kernel.org (sea.lore.kernel.org\n [IPv6:2600:3c0a:e001:db::12fc:5321])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4frTJZ6wvGz1xv0\n\tfor ; Thu, 09 Apr 2026 02:38:06 +1000 (AEST)","from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby sea.lore.kernel.org (Postfix) with ESMTP id CADED3063107\n\tfor ; Wed, 8 Apr 2026 16:35:32 +0000 (UTC)","from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id 0ACF83BAD8F;\n\tWed, 8 Apr 2026 16:35:32 +0000 (UTC)","from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc\n [91.216.245.30])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby smtp.subspace.kernel.org (Postfix) with ESMTPS id 1A8293A1A4D;\n\tWed, 8 Apr 2026 16:35:29 +0000 (UTC)","by Chamillionaire.breakpoint.cc (Postfix, from userid 1003)\n\tid 4BE9360560; Wed, 08 Apr 2026 18:35:28 +0200 (CEST)"],"ARC-Seal":"i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1775666131; cv=none;\n b=Egz3sJ1B1Yx117fYvgP5aYoIUOBs8LMmCKykbZZrFXmgbn0nUYhX2w9YQN+ftBefOR+kUhLvHTEalNGDzDIm8o65ssOTfkxSZgFsIYe25O4P7zax0swBuxV3Wu74DxuvlniSsYT/I4yOik1Cl4UL+3g+d8q5Gf5k+b/LPOPJd9E=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1775666131; c=relaxed/simple;\n\tbh=SjMNDw3SfdzJVLoRRDNS82BHpA3RIY3BkTvJxwqHNiw=;\n\th=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References:\n\t MIME-Version;\n b=ks18xNQBdKC6NKyvX525fUK10gkHFvV0OMy2zqawZwSNinW5bMV5g7r3CYA6WqXIsIO+tfYd8Sllt/ncAtOUgdO0ktZE3Y4ZxoIxMesY4cjTgf+NC3gqG3wyPNQqES6PeaZ9BGIqRfxYOBXII9ye1um12/9GTvwZvLhGBYPti8A=","ARC-Authentication-Results":"i=1; smtp.subspace.kernel.org;\n dmarc=none (p=none dis=none) header.from=strlen.de;\n spf=pass smtp.mailfrom=Chamillionaire.breakpoint.cc;\n arc=none smtp.client-ip=91.216.245.30","From":"Florian Westphal ","To":"","Cc":"Paolo Abeni ,\n\t\"David S. Miller\" ,\n\tEric Dumazet ,\n\tJakub Kicinski ,\n\t,\n\tpablo@netfilter.org","Subject":"[PATCH net 3/7] netfilter: xt_multiport: validate range encoding in\n checkentry","Date":"Wed, 8 Apr 2026 18:35:08 +0200","Message-ID":"<20260408163512.30537-4-fw@strlen.de>","X-Mailer":"git-send-email 2.52.0","In-Reply-To":"<20260408163512.30537-1-fw@strlen.de>","References":"<20260408163512.30537-1-fw@strlen.de>","Precedence":"bulk","X-Mailing-List":"netfilter-devel@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit"},"content":"From: Ren Wei \n\nports_match_v1() treats any non-zero pflags entry as the start of a\nport range and unconditionally consumes the next ports[] element as\nthe range end.\n\nThe checkentry path currently validates protocol, flags and count, but\nit does not validate the range encoding itself. As a result, malformed\nrules can mark the last slot as a range start or place two range starts\nback to back, leaving ports_match_v1() to step past the last valid\nports[] element while interpreting the rule.\n\nReject malformed multiport v1 rules in checkentry by validating that\neach range start has a following element and that the following element\nis not itself marked as another range start.\n\nFixes: a89ecb6a2ef7 (\"[NETFILTER]: x_tables: unify IPv4/IPv6 multiport match\")\nReported-by: Yifan Wu \nReported-by: Juefei Pu \nCo-developed-by: Yuan Tan \nSigned-off-by: Yuan Tan \nSuggested-by: Xin Liu \nTested-by: Yuhang Zheng \nSigned-off-by: Ren Wei \nSigned-off-by: Florian Westphal \n---\n net/netfilter/xt_multiport.c | 34 ++++++++++++++++++++++++++++++----\n 1 file changed, 30 insertions(+), 4 deletions(-)","diff":"diff --git a/net/netfilter/xt_multiport.c b/net/netfilter/xt_multiport.c\nindex 44a00f5acde8..a1691ff405d3 100644\n--- a/net/netfilter/xt_multiport.c\n+++ b/net/netfilter/xt_multiport.c\n@@ -105,6 +105,28 @@ multiport_mt(const struct sk_buff *skb, struct xt_action_param *par)\n \treturn ports_match_v1(multiinfo, ntohs(pptr[0]), ntohs(pptr[1]));\n }\n \n+static bool\n+multiport_valid_ranges(const struct xt_multiport_v1 *multiinfo)\n+{\n+\tunsigned int i;\n+\n+\tfor (i = 0; i < multiinfo->count; i++) {\n+\t\tif (!multiinfo->pflags[i])\n+\t\t\tcontinue;\n+\n+\t\tif (++i >= multiinfo->count)\n+\t\t\treturn false;\n+\n+\t\tif (multiinfo->pflags[i])\n+\t\t\treturn false;\n+\n+\t\tif (multiinfo->ports[i - 1] > multiinfo->ports[i])\n+\t\t\treturn false;\n+\t}\n+\n+\treturn true;\n+}\n+\n static inline bool\n check(u_int16_t proto,\n u_int8_t ip_invflags,\n@@ -127,8 +149,10 @@ static int multiport_mt_check(const struct xt_mtchk_param *par)\n \tconst struct ipt_ip *ip = par->entryinfo;\n \tconst struct xt_multiport_v1 *multiinfo = par->matchinfo;\n \n-\treturn check(ip->proto, ip->invflags, multiinfo->flags,\n-\t\t multiinfo->count) ? 0 : -EINVAL;\n+\tif (!check(ip->proto, ip->invflags, multiinfo->flags, multiinfo->count))\n+\t\treturn -EINVAL;\n+\n+\treturn multiport_valid_ranges(multiinfo) ? 0 : -EINVAL;\n }\n \n static int multiport_mt6_check(const struct xt_mtchk_param *par)\n@@ -136,8 +160,10 @@ static int multiport_mt6_check(const struct xt_mtchk_param *par)\n \tconst struct ip6t_ip6 *ip = par->entryinfo;\n \tconst struct xt_multiport_v1 *multiinfo = par->matchinfo;\n \n-\treturn check(ip->proto, ip->invflags, multiinfo->flags,\n-\t\t multiinfo->count) ? 0 : -EINVAL;\n+\tif (!check(ip->proto, ip->invflags, multiinfo->flags, multiinfo->count))\n+\t\treturn -EINVAL;\n+\n+\treturn multiport_valid_ranges(multiinfo) ? 0 : -EINVAL;\n }\n \n static struct xt_match multiport_mt_reg[] __read_mostly = {\n","prefixes":["net","3/7"]}