From patchwork Mon Mar 7 03:13:00 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Wang X-Patchwork-Id: 592732 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4942C140C41 for ; Mon, 7 Mar 2016 14:17:13 +1100 (AEDT) Received: from localhost ([::1]:53190 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aclfT-0008Qa-3F for incoming@patchwork.ozlabs.org; Sun, 06 Mar 2016 22:17:11 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49763) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aclcv-0003ec-9L for qemu-devel@nongnu.org; Sun, 06 Mar 2016 22:14:34 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aclcr-0000Aj-0A for qemu-devel@nongnu.org; Sun, 06 Mar 2016 22:14:33 -0500 Received: from mx1.redhat.com ([209.132.183.28]:42794) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aclcq-0000Af-QP for qemu-devel@nongnu.org; Sun, 06 Mar 2016 22:14:28 -0500 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (Postfix) with ESMTPS id 86BA87F09D; Mon, 7 Mar 2016 03:14:28 +0000 (UTC) Received: from jason-ThinkPad-T430s.redhat.com (vpn1-5-187.pek2.redhat.com [10.72.5.187]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u273D2MR023865; Sun, 6 Mar 2016 22:14:24 -0500 From: Jason Wang To: peter.maydell@linaro.org, qemu-devel@nongnu.org Date: Mon, 7 Mar 2016 11:13:00 +0800 Message-Id: <1457320380-5111-15-git-send-email-jasowang@redhat.com> In-Reply-To: <1457320380-5111-1-git-send-email-jasowang@redhat.com> References: <1457320380-5111-1-git-send-email-jasowang@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: Jason Wang , Prasad J Pandit Subject: [Qemu-devel] [PULL 14/14] 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org 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 Signed-off-by: Jason Wang --- net/checksum.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/net/checksum.c b/net/checksum.c index b5016ab..d0fa424 100644 --- a/net/checksum.c +++ b/net/checksum.c @@ -60,6 +60,11 @@ 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; @@ -77,8 +82,9 @@ 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;