From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D6799C433F5 for ; Mon, 14 Feb 2022 10:32:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347859AbiBNKc7 (ORCPT ); Mon, 14 Feb 2022 05:32:59 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:37492 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348119AbiBNKar (ORCPT ); Mon, 14 Feb 2022 05:30:47 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9DE706A3A7; Mon, 14 Feb 2022 01:59:21 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id CCB9860B33; Mon, 14 Feb 2022 09:59:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B1914C340E9; Mon, 14 Feb 2022 09:59:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1644832760; bh=zxZs4NkyjrI2gPfX4TXx/y5il8D5vI+faSq/lO+mImo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XaxbBQzfDvb9b6Fdc3+3hj9lnTUdF1PD5DspaLeXVdHPNfEJyhELACeW6oZRQ3xn3 sOQWbirwhVkYy2N1dKeTIp9S4e30psL9DIZIsRHvBVSlvWvbMCMbYuAFJpAPM9rffZ ESa9buv2ABFjkagrv++yccpZU7VWl1fS6USuadnI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Florian Westphal , Pablo Neira Ayuso , Sasha Levin Subject: [PATCH 5.16 116/203] netfilter: nft_payload: dont allow th access for fragments Date: Mon, 14 Feb 2022 10:26:00 +0100 Message-Id: <20220214092514.195957183@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220214092510.221474733@linuxfoundation.org> References: <20220214092510.221474733@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Florian Westphal [ Upstream commit a9e8503def0fd4ed89ade1f61c315f904581d439 ] Loads relative to ->thoff naturally expect that this points to the transport header, but this is only true if pkt->fragoff == 0. This has little effect for rulesets with connection tracking/nat because these enable ip defra. For other rulesets this prevents false matches. Fixes: 96518518cc41 ("netfilter: add nftables") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- net/netfilter/nft_exthdr.c | 2 +- net/netfilter/nft_payload.c | 9 +++++---- 2 files changed, 6 insertions(+), 5 deletions(-) diff --git a/net/netfilter/nft_exthdr.c b/net/netfilter/nft_exthdr.c index dbe1f2e7dd9ed..9e927ab4df151 100644 --- a/net/netfilter/nft_exthdr.c +++ b/net/netfilter/nft_exthdr.c @@ -167,7 +167,7 @@ nft_tcp_header_pointer(const struct nft_pktinfo *pkt, { struct tcphdr *tcph; - if (pkt->tprot != IPPROTO_TCP) + if (pkt->tprot != IPPROTO_TCP || pkt->fragoff) return NULL; tcph = skb_header_pointer(pkt->skb, nft_thoff(pkt), sizeof(*tcph), buffer); diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c index 58e96a0fe0b4c..a4fbce560bddb 100644 --- a/net/netfilter/nft_payload.c +++ b/net/netfilter/nft_payload.c @@ -83,7 +83,7 @@ static int __nft_payload_inner_offset(struct nft_pktinfo *pkt) { unsigned int thoff = nft_thoff(pkt); - if (!(pkt->flags & NFT_PKTINFO_L4PROTO)) + if (!(pkt->flags & NFT_PKTINFO_L4PROTO) || pkt->fragoff) return -1; switch (pkt->tprot) { @@ -147,7 +147,7 @@ void nft_payload_eval(const struct nft_expr *expr, offset = skb_network_offset(skb); break; case NFT_PAYLOAD_TRANSPORT_HEADER: - if (!(pkt->flags & NFT_PKTINFO_L4PROTO)) + if (!(pkt->flags & NFT_PKTINFO_L4PROTO) || pkt->fragoff) goto err; offset = nft_thoff(pkt); break; @@ -657,7 +657,7 @@ static void nft_payload_set_eval(const struct nft_expr *expr, offset = skb_network_offset(skb); break; case NFT_PAYLOAD_TRANSPORT_HEADER: - if (!(pkt->flags & NFT_PKTINFO_L4PROTO)) + if (!(pkt->flags & NFT_PKTINFO_L4PROTO) || pkt->fragoff) goto err; offset = nft_thoff(pkt); break; @@ -696,7 +696,8 @@ static void nft_payload_set_eval(const struct nft_expr *expr, if (priv->csum_type == NFT_PAYLOAD_CSUM_SCTP && pkt->tprot == IPPROTO_SCTP && skb->ip_summed != CHECKSUM_PARTIAL) { - if (nft_payload_csum_sctp(skb, nft_thoff(pkt))) + if (pkt->fragoff == 0 && + nft_payload_csum_sctp(skb, nft_thoff(pkt))) goto err; } -- 2.34.1