From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754715Ab2GIOnp (ORCPT ); Mon, 9 Jul 2012 10:43:45 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:38243 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754445Ab2GIOiR (ORCPT ); Mon, 9 Jul 2012 10:38:17 -0400 Message-Id: <20120709143121.032548570@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Mon, 09 Jul 2012 15:31:46 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Paul Moore , "David S. Miller" Subject: [ 30/48] cipso: handle CIPSO options correctly when NetLabel is disabled In-Reply-To: <20120709143116.348975190@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 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-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paul Moore [ Upstream commit 20e2a86485967c385d7c7befc1646e4d1d39362e ] When NetLabel is not enabled, e.g. CONFIG_NETLABEL=n, and the system receives a CIPSO tagged packet it is dropped (cipso_v4_validate() returns non-zero). In most cases this is the correct and desired behavior, however, in the case where we are simply forwarding the traffic, e.g. acting as a network bridge, this becomes a problem. This patch fixes the forwarding problem by providing the basic CIPSO validation code directly in ip_options_compile() without the need for the NetLabel or CIPSO code. The new validation code can not perform any of the CIPSO option label/value verification that cipso_v4_validate() does, but it can verify the basic CIPSO option format. The behavior when NetLabel is enabled is unchanged. Signed-off-by: Paul Moore Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- include/net/cipso_ipv4.h | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/include/net/cipso_ipv4.h b/include/net/cipso_ipv4.h index 9808877..a7a683e 100644 --- a/include/net/cipso_ipv4.h +++ b/include/net/cipso_ipv4.h @@ -42,6 +42,7 @@ #include #include #include +#include /* known doi values */ #define CIPSO_V4_DOI_UNKNOWN 0x00000000 @@ -285,7 +286,33 @@ static inline int cipso_v4_skbuff_getattr(const struct sk_buff *skb, static inline int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option) { - return -ENOSYS; + unsigned char *opt = *option; + unsigned char err_offset = 0; + u8 opt_len = opt[1]; + u8 opt_iter; + + if (opt_len < 8) { + err_offset = 1; + goto out; + } + + if (get_unaligned_be32(&opt[2]) == 0) { + err_offset = 2; + goto out; + } + + for (opt_iter = 6; opt_iter < opt_len;) { + if (opt[opt_iter + 1] > (opt_len - opt_iter)) { + err_offset = opt_iter + 1; + goto out; + } + opt_iter += opt[opt_iter + 1]; + } + +out: + *option = opt + err_offset; + return err_offset; + } #endif /* CONFIG_NETLABEL */