From patchwork Wed Mar 2 11:59:58 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Prasad Pandit X-Patchwork-Id: 8480401 Return-Path: X-Original-To: patchwork-qemu-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id B7483C0553 for ; Wed, 2 Mar 2016 12:00:25 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id D7E752037E for ; Wed, 2 Mar 2016 12:00:24 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E23BE20377 for ; Wed, 2 Mar 2016 12:00:18 +0000 (UTC) Received: from localhost ([::1]:55886 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ab5Ry-0005TJ-EZ for patchwork-qemu-devel@patchwork.kernel.org; Wed, 02 Mar 2016 07:00:18 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49498) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ab5Rq-0005T8-9M for qemu-devel@nongnu.org; Wed, 02 Mar 2016 07:00:11 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ab5Rn-00025K-Eo for qemu-devel@nongnu.org; Wed, 02 Mar 2016 07:00:10 -0500 Received: from mx1.redhat.com ([209.132.183.28]:60606) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ab5Rn-00024u-7E for qemu-devel@nongnu.org; Wed, 02 Mar 2016 07:00:07 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (Postfix) with ESMTPS id 246088E3DC; Wed, 2 Mar 2016 12:00:06 +0000 (UTC) Received: from javelin.localdomain (vpn1-4-229.sin2.redhat.com [10.67.4.229]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u22C00uc025476 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Wed, 2 Mar 2016 07:00:02 -0500 From: P J P To: Jason Wang Date: Wed, 2 Mar 2016 17:29:58 +0530 Message-Id: <1456919998-27680-1-git-send-email-ppandit@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: Markus Armbruster , Prasad J Pandit , Qemu Developers , Liu Ling Subject: [Qemu-devel] [PATCH v3] net: check packet payload length X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Prasad J Pandit While computing IP checksum, 'net_checksum_calculate' reads payload length from the packet. It could exceed the given 'data' buffer size. Add a check to avoid it. Reported-by: Liu Ling Signed-off-by: Prasad J Pandit --- net/checksum.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) Update as per review: -> https://lists.gnu.org/archive/html/qemu-devel/2016-02/msg06121.html diff --git a/net/checksum.c b/net/checksum.c index 14c0855..0942437 100644 --- a/net/checksum.c +++ b/net/checksum.c @@ -59,6 +59,11 @@ void net_checksum_calculate(uint8_t *data, int length) int hlen, plen, proto, csum_offset; uint16_t csum; + /* Ensure data has complete L2 & L3 headers. */ + if (length < 14 + 20) { + return; + } + if ((data[14] & 0xf0) != 0x40) return; /* not IPv4 */ hlen = (data[14] & 0x0f) * 4; @@ -76,8 +81,9 @@ void net_checksum_calculate(uint8_t *data, int length) return; } - if (plen < csum_offset+2) - return; + if (plen < csum_offset + 2 || 14 + hlen + plen > length) { + return; + } data[14+hlen+csum_offset] = 0; data[14+hlen+csum_offset+1] = 0;