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=-16.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 AF70DC4332F for ; Mon, 13 Sep 2021 09:24:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 91D1461004 for ; Mon, 13 Sep 2021 09:24:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238439AbhIMJ0I (ORCPT ); Mon, 13 Sep 2021 05:26:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60610 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238506AbhIMJ0G (ORCPT ); Mon, 13 Sep 2021 05:26:06 -0400 Received: from kadath.azazel.net (kadath.azazel.net [IPv6:2001:8b0:135f:bcd1:e0cb:4eff:fedf:e608]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5B80CC061764 for ; Mon, 13 Sep 2021 02:24:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=azazel.net; s=20190108; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=nTv4sYiQav0PiWMfCsWDuMulxij4RqPN1B6uL2eS2HU=; b=aPePa4owiCHyV0+x0ibKuwzX9w sPIutnnIK5SptuL2T0WKPq0afBZ8vIv1nFMstqEyei6E34YYCwNrIOodep3ev5OyYTrhaeuxmDgjt QvefQqEtPAF4jSYhCS5yTfcO0t/YcGNsa+JONObUU7JiO0RI/SKnLG7OGCUy9mp1S4g1EqlitJ98N 0YHdMfPTFZt5LibSTZpIoIDBE5aWLRwToATdH7JagxGZO54VxvqxbCJEpNR4cTA4ViC6917OY0mXh YPHGufReJ+Ht0Y0+RIPPgC2Elhrh3Sq4y/NciYTpq8knHWphdfutCylYtR6LMnSfe+QAkFrmRZnfo u7iBEtzw==; Received: from ulthar.dreamlands.azazel.net ([2001:8b0:fb7d:d6d7:2e4d:54ff:fe4b:a9ae]) by kadath.azazel.net with esmtp (Exim 4.94.2) (envelope-from ) id 1mPiCm-00GLzi-BA; Mon, 13 Sep 2021 10:24:48 +0100 From: Jeremy Sowden To: Jan Engelhardt Cc: Netfilter Devel , kaskada@email.cz Subject: [xtables-addons 1/4] xt_ipp2p: don't search haystack if it's empty Date: Mon, 13 Sep 2021 10:20:48 +0100 Message-Id: <20210913092051.79743-2-jeremy@azazel.net> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210913092051.79743-1-jeremy@azazel.net> References: <20210913092051.79743-1-jeremy@azazel.net> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 2001:8b0:fb7d:d6d7:2e4d:54ff:fe4b:a9ae X-SA-Exim-Mail-From: jeremy@azazel.net X-SA-Exim-Scanned: No (on kadath.azazel.net); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org All the search functions have a positive minimum packet-length. Signed-off-by: Jeremy Sowden --- extensions/xt_ipp2p.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/extensions/xt_ipp2p.c b/extensions/xt_ipp2p.c index 8fb1b79bb414..4e0fbb675c76 100644 --- a/extensions/xt_ipp2p.c +++ b/extensions/xt_ipp2p.c @@ -842,14 +842,17 @@ ipp2p_mt(const struct sk_buff *skb, struct xt_action_param *par) if (tcph->syn) return 0; /* if SYN bit is set bail out */ if (tcph->rst) return 0; /* if RST bit is set bail out */ - haystack += tcph->doff * 4; /* get TCP-Header-Size */ if (tcph->doff * 4 > hlen) { if (info->debug) pr_info("TCP header indicated packet larger than it is\n"); - hlen = 0; - } else { - hlen -= tcph->doff * 4; + return 0; } + if (tcph->doff * 4 == hlen) + return 0; + + haystack += tcph->doff * 4; /* get TCP-Header-Size */ + hlen -= tcph->doff * 4; + while (matchlist[i].command) { if ((info->cmd & matchlist[i].command) == matchlist[i].command && hlen > matchlist[i].packet_len) @@ -875,14 +878,16 @@ ipp2p_mt(const struct sk_buff *skb, struct xt_action_param *par) { const struct udphdr *udph = (const void *)ip + ip_hdrlen(skb); - haystack += sizeof(*udph); if (sizeof(*udph) > hlen) { if (info->debug) pr_info("UDP header indicated packet larger than it is\n"); - hlen = 0; - } else { - hlen -= sizeof(*udph); + return 0; } + if (sizeof(*udph) == hlen) + return 0; + + haystack += sizeof(*udph); + hlen -= sizeof(*udph); while (udp_list[i].command) { if ((info->cmd & udp_list[i].command) == udp_list[i].command && -- 2.33.0