From patchwork Tue Jun 28 03:35:07 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Wang X-Patchwork-Id: 641322 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 3rds1N16GXz9s9d for ; Tue, 28 Jun 2016 13:36:56 +1000 (AEST) Received: from localhost ([::1]:33947 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bHjpV-0006tf-R7 for incoming@patchwork.ozlabs.org; Mon, 27 Jun 2016 23:36:53 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40780) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bHjo5-0005Pa-GL for qemu-devel@nongnu.org; Mon, 27 Jun 2016 23:35:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bHjo4-0004aE-5i for qemu-devel@nongnu.org; Mon, 27 Jun 2016 23:35:25 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56949) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bHjo3-0004a9-W2 for qemu-devel@nongnu.org; Mon, 27 Jun 2016 23:35:24 -0400 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7ACD37D0D7; Tue, 28 Jun 2016 03:35:23 +0000 (UTC) Received: from jason-ThinkPad-T450s.redhat.com (vpn1-7-210.pek2.redhat.com [10.72.7.210]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u5S3ZBeu004102; Mon, 27 Jun 2016 23:35:20 -0400 From: Jason Wang To: peter.maydell@linaro.org, qemu-devel@nongnu.org Date: Tue, 28 Jun 2016 11:35:07 +0800 Message-Id: <1467084910-14643-3-git-send-email-jasowang@redhat.com> In-Reply-To: <1467084910-14643-1-git-send-email-jasowang@redhat.com> References: <1467084910-14643-1-git-send-email-jasowang@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.26 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Tue, 28 Jun 2016 03:35:23 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 2/5] net: mipsnet: check transmit buffer size before sending X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jason Wang , Prasad J Pandit Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Prasad J Pandit When processing MIPSnet I/O port write operation, it uses a transmit buffer tx_buffer[MAX_ETH_FRAME_SIZE=1514]. Two indices 's->tx_written' and 's->tx_count' are used to control data written to this buffer. If the two were to be equal before writing, it'd lead to an OOB write access beyond tx_buffer. Add check to avoid it. Reported-by: Li Qiang Signed-off-by: Prasad J Pandit Signed-off-by: Jason Wang --- hw/net/mipsnet.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/hw/net/mipsnet.c b/hw/net/mipsnet.c index cf8b823..5115adc 100644 --- a/hw/net/mipsnet.c +++ b/hw/net/mipsnet.c @@ -183,10 +183,12 @@ static void mipsnet_ioport_write(void *opaque, hwaddr addr, break; case MIPSNET_TX_DATA_BUFFER: s->tx_buffer[s->tx_written++] = val; - if (s->tx_written == s->tx_count) { + if ((s->tx_written >= MAX_ETH_FRAME_SIZE) + || (s->tx_written == s->tx_count)) { /* Send buffer. */ - trace_mipsnet_send(s->tx_count); - qemu_send_packet(qemu_get_queue(s->nic), s->tx_buffer, s->tx_count); + trace_mipsnet_send(s->tx_written); + qemu_send_packet(qemu_get_queue(s->nic), + s->tx_buffer, s->tx_written); s->tx_count = s->tx_written = 0; s->intctl |= MIPSNET_INTCTL_TXDONE; s->busy = 1;