From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roel Kluin Subject: [PATCH] cipso: subtraction on unsigned hdr_delta Date: Tue, 03 Mar 2009 23:23:38 +0100 Message-ID: <49ADADEA.8090306@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, "David S. Miller" , Andrew Morton To: paul.moore@hp.com Return-path: Received: from mail-ew0-f177.google.com ([209.85.219.177]:47715 "EHLO mail-ew0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758401AbZCCWXj (ORCPT ); Tue, 3 Mar 2009 17:23:39 -0500 Received: by ewy25 with SMTP id 25so2534157ewy.37 for ; Tue, 03 Mar 2009 14:23:36 -0800 (PST) Sender: netdev-owner@vger.kernel.org List-ID: hdr_delta is unsigned, so take care not to subtract below 0. Signed-off-by: Roel Kluin --- diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c index 7bc9929..b1d862b 100644 --- a/net/ipv4/cipso_ipv4.c +++ b/net/ipv4/cipso_ipv4.c @@ -1999,7 +1999,11 @@ void cipso_v4_sock_delattr(struct sock *sk) iter++; hdr_delta = opt->optlen; opt->optlen = (optlen_new + 3) & ~3; - hdr_delta -= opt->optlen; + + if (hdr_delta > opt->optlen) + hdr_delta -= opt->optlen; + else + hdr_delta = 0; } else { /* only the cipso option was present on the socket so we can * remove the entire option struct */