From patchwork Thu May 19 10:39:31 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Prasad Pandit X-Patchwork-Id: 9126211 Return-Path: X-Original-To: patchwork-qemu-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id A7B019F30C for ; Thu, 19 May 2016 10:40:32 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 115BC20222 for ; Thu, 19 May 2016 10:40:32 +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 7AD252021F for ; Thu, 19 May 2016 10:40:30 +0000 (UTC) Received: from localhost ([::1]:49501 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b3LNV-0006B3-Jz for patchwork-qemu-devel@patchwork.kernel.org; Thu, 19 May 2016 06:40:29 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54167) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b3LMy-000669-GT for qemu-devel@nongnu.org; Thu, 19 May 2016 06:40:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b3LMu-0001ga-Kg for qemu-devel@nongnu.org; Thu, 19 May 2016 06:39:56 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55765) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b3LMu-0001g6-EP for qemu-devel@nongnu.org; Thu, 19 May 2016 06:39:52 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (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 006DBC05B1E4; Thu, 19 May 2016 10:39:52 +0000 (UTC) Received: from javelin.localdomain (vpn1-48-59.bne.redhat.com [10.64.48.59]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u4JAdYRp017840 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Thu, 19 May 2016 06:39:48 -0400 From: P J P To: Qemu Developers Date: Thu, 19 May 2016 16:09:31 +0530 Message-Id: <1463654371-11169-3-git-send-email-ppandit@redhat.com> In-Reply-To: <1463654371-11169-1-git-send-email-ppandit@redhat.com> References: <1463654371-11169-1-git-send-email-ppandit@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Thu, 19 May 2016 10:39:52 +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] [PATCH 2/2] scsi: check dma length before reading scsi command(CVE-2016-4441) 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: Paolo Bonzini , Li Qiang , Prasad J Pandit Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" 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 The 53C9X Fast SCSI Controller(FSC) comes with an internal 16-byte FIFO buffer. It is used to handle command and data transfer. Routine get_cmd() uses DMA to read scsi commands into this buffer. Add check to validate DMA length against buffer size to avoid any overrun. Fixes CVE-2016-4441 Reported-by: Li Qiang Signed-off-by: Prasad J Pandit --- hw/scsi/esp.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c index 01497e6..591c817 100644 --- a/hw/scsi/esp.c +++ b/hw/scsi/esp.c @@ -82,7 +82,7 @@ void esp_request_cancelled(SCSIRequest *req) } } -static uint32_t get_cmd(ESPState *s, uint8_t *buf) +static uint32_t get_cmd(ESPState *s, uint8_t *buf, uint8_t buflen) { uint32_t dmalen; int target; @@ -92,6 +92,9 @@ static uint32_t get_cmd(ESPState *s, uint8_t *buf) dmalen = s->rregs[ESP_TCLO]; dmalen |= s->rregs[ESP_TCMID] << 8; dmalen |= s->rregs[ESP_TCHI] << 16; + if (dmalen > buflen) { + return 0; + } s->dma_memory_read(s->dma_opaque, buf, dmalen); } else { dmalen = s->ti_size; @@ -166,7 +169,7 @@ static void handle_satn(ESPState *s) s->dma_cb = handle_satn; return; } - len = get_cmd(s, buf); + len = get_cmd(s, buf, sizeof(buf)); if (len) do_cmd(s, buf); } @@ -180,7 +183,7 @@ static void handle_s_without_atn(ESPState *s) s->dma_cb = handle_s_without_atn; return; } - len = get_cmd(s, buf); + len = get_cmd(s, buf, sizeof(buf)); if (len) { do_busid_cmd(s, buf, 0); } @@ -192,7 +195,7 @@ static void handle_satn_stop(ESPState *s) s->dma_cb = handle_satn_stop; return; } - s->cmdlen = get_cmd(s, s->cmdbuf); + s->cmdlen = get_cmd(s, s->cmdbuf, sizeof(s->cmdbuf)); if (s->cmdlen) { trace_esp_handle_satn_stop(s->cmdlen); s->do_cmd = 1;