From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758223Ab3KYO0n (ORCPT ); Mon, 25 Nov 2013 09:26:43 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:58861 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753963Ab3KYNxi (ORCPT ); Mon, 25 Nov 2013 08:53:38 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "David S. Miller" , "Seif Mazareeb" , "Paul Moore" Date: Mon, 25 Nov 2013 13:44:29 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 19/87] net: fix cipso packet validation when !NETLABEL In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.212 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.53-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Seif Mazareeb [ Upstream commit f2e5ddcc0d12f9c4c7b254358ad245c9dddce13b ] When CONFIG_NETLABEL is disabled, the cipso_v4_validate() function could loop forever in the main loop if opt[opt_iter +1] == 0, this will causing a kernel crash in an SMP system, since the CPU executing this function will stall /not respond to IPIs. This problem can be reproduced by running the IP Stack Integrity Checker (http://isic.sourceforge.net) using the following command on a Linux machine connected to DUT: "icmpsic -s rand -d -r 123456" wait (1-2 min) Signed-off-by: Seif Mazareeb Acked-by: Paul Moore Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- include/net/cipso_ipv4.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/include/net/cipso_ipv4.h b/include/net/cipso_ipv4.h index a7a683e..a8c2ef6 100644 --- a/include/net/cipso_ipv4.h +++ b/include/net/cipso_ipv4.h @@ -290,6 +290,7 @@ static inline int cipso_v4_validate(const struct sk_buff *skb, unsigned char err_offset = 0; u8 opt_len = opt[1]; u8 opt_iter; + u8 tag_len; if (opt_len < 8) { err_offset = 1; @@ -302,11 +303,12 @@ static inline int cipso_v4_validate(const struct sk_buff *skb, } for (opt_iter = 6; opt_iter < opt_len;) { - if (opt[opt_iter + 1] > (opt_len - opt_iter)) { + tag_len = opt[opt_iter + 1]; + if ((tag_len == 0) || (opt[opt_iter + 1] > (opt_len - opt_iter))) { err_offset = opt_iter + 1; goto out; } - opt_iter += opt[opt_iter + 1]; + opt_iter += tag_len; } out: