From patchwork Tue Mar 21 14:13:00 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg Kurz X-Patchwork-Id: 9636653 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4C56F602CC for ; Tue, 21 Mar 2017 14:14:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4115428305 for ; Tue, 21 Mar 2017 14:14:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 35B3828329; Tue, 21 Mar 2017 14:14:23 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 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.wl.linuxfoundation.org (Postfix) with ESMTPS id 85FF52830A for ; Tue, 21 Mar 2017 14:14:22 +0000 (UTC) Received: from localhost ([::1]:40476 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cqKYH-00089b-Kl for patchwork-qemu-devel@patchwork.kernel.org; Tue, 21 Mar 2017 10:14:21 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57697) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cqKXT-00086Z-VG for qemu-devel@nongnu.org; Tue, 21 Mar 2017 10:13:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cqKXP-0002sg-VC for qemu-devel@nongnu.org; Tue, 21 Mar 2017 10:13:31 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:49833 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cqKXP-0002sR-OZ for qemu-devel@nongnu.org; Tue, 21 Mar 2017 10:13:27 -0400 Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v2LE9523005777 for ; Tue, 21 Mar 2017 10:13:27 -0400 Received: from e06smtp11.uk.ibm.com (e06smtp11.uk.ibm.com [195.75.94.107]) by mx0b-001b2d01.pphosted.com with ESMTP id 29ajffc4qy-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 21 Mar 2017 10:13:26 -0400 Received: from localhost by e06smtp11.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Tue, 21 Mar 2017 14:13:23 -0000 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v2LEDNqP37945410; Tue, 21 Mar 2017 14:13:23 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5D3A9A4057; Tue, 21 Mar 2017 14:13:02 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 4AF81A404D; Tue, 21 Mar 2017 14:13:02 +0000 (GMT) Received: from smtp.lab.toulouse-stg.fr.ibm.com (unknown [9.101.4.1]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 21 Mar 2017 14:13:02 +0000 (GMT) Received: from bahia.lan (icon-9-164-181-250.megacenter.de.ibm.com [9.164.181.250]) by smtp.lab.toulouse-stg.fr.ibm.com (Postfix) with ESMTP id 077A1220195; Tue, 21 Mar 2017 15:13:21 +0100 (CET) From: Greg Kurz To: qemu-devel@nongnu.org Date: Tue, 21 Mar 2017 15:13:00 +0100 X-Mailer: git-send-email 2.7.4 In-Reply-To: <1490105580-5008-1-git-send-email-groug@kaod.org> References: <1490105580-5008-1-git-send-email-groug@kaod.org> MIME-Version: 1.0 X-TM-AS-GCONF: 00 x-cbid: 17032114-0040-0000-0000-0000036A5177 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17032114-0041-0000-0000-00001F5BDD0A Message-Id: <1490105580-5008-3-git-send-email-groug@kaod.org> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-03-21_11:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=4 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1702020001 definitions=main-1703210126 X-MIME-Autoconverted: from 8bit to quoted-printable by mx0b-001b2d01.pphosted.com id v2LE9523005777 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] [fuzzy] X-Received-From: 148.163.158.5 Subject: [Qemu-devel] [PULL 2/2] 9pfs: proxy: assert if unmarshal fails 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: Peter Maydell , Greg Kurz Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Replies from the virtfs proxy are made up of a fixed-size header (8 bytes) and a payload of variable size (maximum 64kb). When receiving a reply, the proxy backend first reads the whole header and then unmarshals it. If the header is okay, it then does the same operation with the payload. Since the proxy backend uses a pre-allocated buffer which has enough room for a header and the maximum payload size, marshalling should never fail with fixed size arguments. Any error here is likely to result from a more serious corruption in QEMU and we'd better dump core right away. This patch adds error checks where they are missing and converts the associated error paths into assertions. This should also address Coverity's complaints CID 1348519 and CID 1348520, about not always checking the return value of proxy_unmarshal(). Signed-off-by: Greg Kurz Reviewed-by: Philippe Mathieu-Daudé --- hw/9pfs/9p-proxy.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/hw/9pfs/9p-proxy.c b/hw/9pfs/9p-proxy.c index f4aa7a9d70f8..28b20a7c3dfa 100644 --- a/hw/9pfs/9p-proxy.c +++ b/hw/9pfs/9p-proxy.c @@ -165,7 +165,8 @@ static int v9fs_receive_response(V9fsProxy *proxy, int type, return retval; } reply->iov_len = PROXY_HDR_SZ; - proxy_unmarshal(reply, 0, "dd", &header.type, &header.size); + retval = proxy_unmarshal(reply, 0, "dd", &header.type, &header.size); + assert(retval == 4 * 2); /* * if response size > PROXY_MAX_IO_SZ, read the response but ignore it and * return -ENOBUFS @@ -194,9 +195,7 @@ static int v9fs_receive_response(V9fsProxy *proxy, int type, if (header.type == T_ERROR) { int ret; ret = proxy_unmarshal(reply, PROXY_HDR_SZ, "d", status); - if (ret < 0) { - *status = ret; - } + assert(ret == 4); return 0; } @@ -213,6 +212,7 @@ static int v9fs_receive_response(V9fsProxy *proxy, int type, &prstat.st_atim_sec, &prstat.st_atim_nsec, &prstat.st_mtim_sec, &prstat.st_mtim_nsec, &prstat.st_ctim_sec, &prstat.st_ctim_nsec); + assert(retval == 8 * 3 + 4 * 3 + 8 * 10); prstat_to_stat(response, &prstat); break; } @@ -225,6 +225,7 @@ static int v9fs_receive_response(V9fsProxy *proxy, int type, &prstfs.f_files, &prstfs.f_ffree, &prstfs.f_fsid[0], &prstfs.f_fsid[1], &prstfs.f_namelen, &prstfs.f_frsize); + assert(retval == 8 * 11); prstatfs_to_statfs(response, &prstfs); break; } @@ -246,7 +247,8 @@ static int v9fs_receive_response(V9fsProxy *proxy, int type, break; } case T_GETVERSION: - proxy_unmarshal(reply, PROXY_HDR_SZ, "q", response); + retval = proxy_unmarshal(reply, PROXY_HDR_SZ, "q", response); + assert(retval == 8); break; default: return -1; @@ -274,18 +276,16 @@ static int v9fs_receive_status(V9fsProxy *proxy, return retval; } reply->iov_len = PROXY_HDR_SZ; - proxy_unmarshal(reply, 0, "dd", &header.type, &header.size); - if (header.size != sizeof(int)) { - *status = -ENOBUFS; - return 0; - } + retval = proxy_unmarshal(reply, 0, "dd", &header.type, &header.size); + assert(retval == 4 * 2); retval = socket_read(proxy->sockfd, reply->iov_base + PROXY_HDR_SZ, header.size); if (retval < 0) { return retval; } reply->iov_len += header.size; - proxy_unmarshal(reply, PROXY_HDR_SZ, "d", status); + retval = proxy_unmarshal(reply, PROXY_HDR_SZ, "d", status); + assert(retval == 4); return 0; }