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=-6.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 A6EF9C43441 for ; Sun, 11 Nov 2018 22:30:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6B016223CA for ; Sun, 11 Nov 2018 22:30:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="qjpnk0BB" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6B016223CA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389011AbeKLIUn (ORCPT ); Mon, 12 Nov 2018 03:20:43 -0500 Received: from mail.kernel.org ([198.145.29.99]:46000 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733238AbeKLIUm (ORCPT ); Mon, 12 Nov 2018 03:20:42 -0500 Received: from localhost (unknown [206.108.79.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5BD48223D8; Sun, 11 Nov 2018 22:30:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541975446; bh=17bCuUhlEB2hKKwXd3gJ5cPxGO/pq5VCWdllBQ2NzDc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qjpnk0BBkzXc0jJtm2Bghu51RsyxhblhUAcSTI+M4mCWZ1FUnCmjUweBkS1SW/bNT 1uzKnop+qMQxfpdipaLKz6CwaTTlLMcseUaKHDRxNfI0P0htHQ0S0YS20SxVIZ8PPD pSiOqQeBMmx59cKNnRerpV1cfqR31L+k3PP0iRJQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stefan Nuernberger , David Woodhouse , Simon Veith , Paul Moore , "David S. Miller" Subject: [PATCH 4.18 209/350] net/ipv4: defensive cipso option parsing Date: Sun, 11 Nov 2018 14:21:13 -0800 Message-Id: <20181111221716.774666650@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181111221707.043394111@linuxfoundation.org> References: <20181111221707.043394111@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stefan Nuernberger commit 076ed3da0c9b2f88d9157dbe7044a45641ae369e upstream. commit 40413955ee26 ("Cipso: cipso_v4_optptr enter infinite loop") fixed a possible infinite loop in the IP option parsing of CIPSO. The fix assumes that ip_options_compile filtered out all zero length options and that no other one-byte options beside IPOPT_END and IPOPT_NOOP exist. While this assumption currently holds true, add explicit checks for zero length and invalid length options to be safe for the future. Even though ip_options_compile should have validated the options, the introduction of new one-byte options can still confuse this code without the additional checks. Signed-off-by: Stefan Nuernberger Cc: David Woodhouse Cc: Simon Veith Cc: stable@vger.kernel.org Acked-by: Paul Moore Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/cipso_ipv4.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) --- a/net/ipv4/cipso_ipv4.c +++ b/net/ipv4/cipso_ipv4.c @@ -1512,7 +1512,7 @@ static int cipso_v4_parsetag_loc(const s * * Description: * Parse the packet's IP header looking for a CIPSO option. Returns a pointer - * to the start of the CIPSO option on success, NULL if one if not found. + * to the start of the CIPSO option on success, NULL if one is not found. * */ unsigned char *cipso_v4_optptr(const struct sk_buff *skb) @@ -1522,10 +1522,8 @@ unsigned char *cipso_v4_optptr(const str int optlen; int taglen; - for (optlen = iph->ihl*4 - sizeof(struct iphdr); optlen > 0; ) { + for (optlen = iph->ihl*4 - sizeof(struct iphdr); optlen > 1; ) { switch (optptr[0]) { - case IPOPT_CIPSO: - return optptr; case IPOPT_END: return NULL; case IPOPT_NOOP: @@ -1534,6 +1532,11 @@ unsigned char *cipso_v4_optptr(const str default: taglen = optptr[1]; } + if (!taglen || taglen > optlen) + return NULL; + if (optptr[0] == IPOPT_CIPSO) + return optptr; + optlen -= taglen; optptr += taglen; }