From nobody Wed Nov 5 17:43:26 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1496751607104501.68348320927385; Tue, 6 Jun 2017 05:20:07 -0700 (PDT) Received: from localhost ([::1]:38140 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dIDSp-0003Nz-Ae for importer@patchew.org; Tue, 06 Jun 2017 08:19:59 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56937) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dIDQu-0001tQ-HA for qemu-devel@nongnu.org; Tue, 06 Jun 2017 08:18:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dIDQs-0005Gd-4g for qemu-devel@nongnu.org; Tue, 06 Jun 2017 08:18:00 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54450) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dIDQr-0005GQ-VH for qemu-devel@nongnu.org; Tue, 06 Jun 2017 08:17:58 -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 1270E3DBCC; Tue, 6 Jun 2017 12:17:57 +0000 (UTC) Received: from donizetti.redhat.com (ovpn-117-248.ams2.redhat.com [10.36.117.248]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v56CHmMB003973; Tue, 6 Jun 2017 08:17:55 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 1270E3DBCC Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=pbonzini@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 1270E3DBCC From: Paolo Bonzini To: qemu-devel@nongnu.org Date: Tue, 6 Jun 2017 14:17:43 +0200 Message-Id: <20170606121747.25356-4-pbonzini@redhat.com> In-Reply-To: <20170606121747.25356-1-pbonzini@redhat.com> References: <20170606121747.25356-1-pbonzini@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 [10.5.110.30]); Tue, 06 Jun 2017 12:17:57 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH 3/7] megasas: do not read iovec count more than once from frame 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: zyy4013@stu.ouc.edu.cn, hare@suse.de, ppandit@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Avoid TOC-TOU bugs depending on how the compiler behaves. Signed-off-by: Paolo Bonzini --- hw/scsi/megasas.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/hw/scsi/megasas.c b/hw/scsi/megasas.c index 1888118e5f..c353118882 100644 --- a/hw/scsi/megasas.c +++ b/hw/scsi/megasas.c @@ -675,15 +675,16 @@ out: static int megasas_map_dcmd(MegasasState *s, MegasasCmd *cmd) { dma_addr_t iov_pa, iov_size; + int iov_count; =20 cmd->flags =3D le16_to_cpu(cmd->frame->header.flags); - if (!cmd->frame->header.sge_count) { + iov_count =3D cmd->frame->header.sge_count; + if (!iov_count) { trace_megasas_dcmd_zero_sge(cmd->index); cmd->iov_size =3D 0; return 0; - } else if (cmd->frame->header.sge_count > 1) { - trace_megasas_dcmd_invalid_sge(cmd->index, - cmd->frame->header.sge_count); + } else if (iov_count > 1) { + trace_megasas_dcmd_invalid_sge(cmd->index, iov_count); cmd->iov_size =3D 0; return -EINVAL; } --=20 2.13.0