From patchwork Thu Aug 8 06:56:36 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Prasad Pandit X-Patchwork-Id: 11083365 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9E50B14DB for ; Thu, 8 Aug 2019 06:59:05 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8C7862897D for ; Thu, 8 Aug 2019 06:59:05 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7EDCB28B09; Thu, 8 Aug 2019 06:59:05 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 29BC32897D for ; Thu, 8 Aug 2019 06:59:05 +0000 (UTC) Received: from localhost ([::1]:47212 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hvcO8-0001hZ-9L for patchwork-qemu-devel@patchwork.kernel.org; Thu, 08 Aug 2019 02:59:04 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:50919) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hvcNp-0001Ho-Jt for qemu-devel@nongnu.org; Thu, 08 Aug 2019 02:58:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hvcNo-0001pZ-IQ for qemu-devel@nongnu.org; Thu, 08 Aug 2019 02:58:45 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34118) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hvcNo-0001nS-Cw for qemu-devel@nongnu.org; Thu, 08 Aug 2019 02:58:44 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 83915C049E10; Thu, 8 Aug 2019 06:58:43 +0000 (UTC) Received: from localhost.localdomain (unknown [10.65.150.157]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4C6D75D9DC; Thu, 8 Aug 2019 06:58:38 +0000 (UTC) From: P J P To: QEMU Developers Date: Thu, 8 Aug 2019 12:26:36 +0530 Message-Id: <20190808065636.28787-1-ppandit@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Thu, 08 Aug 2019 06:58:43 +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] ide: ahci: add check to avoid null dereference (CVE-2019-12067) X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Bugs SysSec , John Snow , Prasad J Pandit Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Prasad J Pandit AHCI emulator while committing DMA buffer in ahci_commit_buf() may do a NULL dereference if the command header 'ad->cur_cmd' is null. Add check to avoid it. Reported-by: Bugs SysSec Signed-off-by: Prasad J Pandit --- hw/ide/ahci.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c index 00ba422a48..9fff94075b 100644 --- a/hw/ide/ahci.c +++ b/hw/ide/ahci.c @@ -1458,8 +1458,10 @@ static void ahci_commit_buf(IDEDMA *dma, uint32_t tx_bytes) { AHCIDevice *ad = DO_UPCAST(AHCIDevice, dma, dma); - tx_bytes += le32_to_cpu(ad->cur_cmd->status); - ad->cur_cmd->status = cpu_to_le32(tx_bytes); + if (ad->cur_cmd) { + tx_bytes += le32_to_cpu(ad->cur_cmd->status); + ad->cur_cmd->status = cpu_to_le32(tx_bytes); + } } static int ahci_dma_rw_buf(IDEDMA *dma, int is_write)