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 X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B20EC48BE5 for ; Wed, 23 Jun 2021 17:02:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 259A2611AC for ; Wed, 23 Jun 2021 17:02:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229755AbhFWRFE (ORCPT ); Wed, 23 Jun 2021 13:05:04 -0400 Received: from mail.netfilter.org ([217.70.188.207]:33444 "EHLO mail.netfilter.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229523AbhFWRFE (ORCPT ); Wed, 23 Jun 2021 13:05:04 -0400 Received: from localhost.localdomain (unknown [90.77.255.23]) by mail.netfilter.org (Postfix) with ESMTPSA id 556306427C for ; Wed, 23 Jun 2021 19:01:21 +0200 (CEST) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Subject: [PATCH net-next 1/6] netfilter: nft_exthdr: Search chunks in SCTP packets only Date: Wed, 23 Jun 2021 19:02:36 +0200 Message-Id: <20210623170241.59902-2-pablo@netfilter.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210623170241.59902-1-pablo@netfilter.org> References: <20210623170241.59902-1-pablo@netfilter.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org From: Phil Sutter Since user space does not generate a payload dependency, plain sctp chunk matches cause searching in non-SCTP packets, too. Avoid this potential mis-interpretation of packet data by checking pkt->tprot. Fixes: 133dc203d77df ("netfilter: nft_exthdr: Support SCTP chunks") Signed-off-by: Phil Sutter Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_exthdr.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nft_exthdr.c b/net/netfilter/nft_exthdr.c index 7f705b5c09de..9cf86be2cff4 100644 --- a/net/netfilter/nft_exthdr.c +++ b/net/netfilter/nft_exthdr.c @@ -312,6 +312,9 @@ static void nft_exthdr_sctp_eval(const struct nft_expr *expr, const struct sctp_chunkhdr *sch; struct sctp_chunkhdr _sch; + if (pkt->tprot != IPPROTO_SCTP) + goto err; + do { sch = skb_header_pointer(pkt->skb, offset, sizeof(_sch), &_sch); if (!sch || !sch->length) @@ -334,7 +337,7 @@ static void nft_exthdr_sctp_eval(const struct nft_expr *expr, } offset += SCTP_PAD4(ntohs(sch->length)); } while (offset < pkt->skb->len); - +err: if (priv->flags & NFT_EXTHDR_F_PRESENT) nft_reg_store8(dest, false); else -- 2.30.2