From patchwork Fri Aug 26 15:07:00 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kurz X-Patchwork-Id: 9301585 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 AAB9D601C0 for ; Fri, 26 Aug 2016 15:11:20 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9A352295F0 for ; Fri, 26 Aug 2016 15:11:20 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8EB6129625; Fri, 26 Aug 2016 15:11:20 +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 61041295F0 for ; Fri, 26 Aug 2016 15:11:19 +0000 (UTC) Received: from localhost ([::1]:60940 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bdIms-0005Kg-F7 for patchwork-qemu-devel@patchwork.kernel.org; Fri, 26 Aug 2016 11:11:18 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44470) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bdIiz-0001kv-Ho for qemu-devel@nongnu.org; Fri, 26 Aug 2016 11:07:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bdIit-0002cn-IC for qemu-devel@nongnu.org; Fri, 26 Aug 2016 11:07:16 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:55947) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bdIit-0002ch-9f for qemu-devel@nongnu.org; Fri, 26 Aug 2016 11:07:11 -0400 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.11/8.16.0.11) with SMTP id u7QF5BCQ069611 for ; Fri, 26 Aug 2016 11:07:10 -0400 Received: from e34.co.us.ibm.com (e34.co.us.ibm.com [32.97.110.152]) by mx0a-001b2d01.pphosted.com with ESMTP id 252pe2ek40-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Fri, 26 Aug 2016 11:07:10 -0400 Received: from localhost by e34.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Fri, 26 Aug 2016 09:07:05 -0600 X-IBM-Helo: d03dlp01.boulder.ibm.com X-IBM-MailFrom: groug@kaod.org Received: from b03cxnp07029.gho.boulder.ibm.com (b03cxnp07029.gho.boulder.ibm.com [9.17.130.16]) by d03dlp01.boulder.ibm.com (Postfix) with ESMTP id BB8C51FF002E; Fri, 26 Aug 2016 09:06:45 -0600 (MDT) Received: from b03ledav003.gho.boulder.ibm.com (b03ledav003.gho.boulder.ibm.com [9.17.130.234]) by b03cxnp07029.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u7QF73uV15008116; Fri, 26 Aug 2016 08:07:03 -0700 Received: from b03ledav003.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A04CE6A03F; Fri, 26 Aug 2016 09:07:03 -0600 (MDT) Received: from bahia.lan (unknown [9.167.235.232]) by b03ledav003.gho.boulder.ibm.com (Postfix) with ESMTP id 18A1C6A03D; Fri, 26 Aug 2016 09:07:01 -0600 (MDT) From: Greg Kurz To: qemu-devel@nongnu.org Date: Fri, 26 Aug 2016 17:07:00 +0200 In-Reply-To: <147222401281.18925.1894824578752486297.stgit@bahia.lan> References: <147222401281.18925.1894824578752486297.stgit@bahia.lan> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16082615-0016-0000-0000-000004840E39 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00005643; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000183; SDB=6.00750026; UDB=6.00354182; IPR=6.00522663; BA=6.00004676; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00012476; XFM=3.00000011; UTC=2016-08-26 15:07:07 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16082615-0017-0000-0000-0000325CBF61 Message-Id: <147222402095.18925.396915168302239352.stgit@bahia.lan> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2016-08-26_11:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=1 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1608260194 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] X-Received-From: 148.163.156.1 Subject: [Qemu-devel] [PATCH v2 1/5] 9p: forbid illegal path names 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 , Felix Wilhelm , "Michael S. Tsirkin" , Greg Kurz , P J P , "Aneesh Kumar K.V" Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Empty path components don't make sense and may cause undefined behavior, depending on the backend. Also, the walk request described in the 9P spec [1] clearly shows that the client is supposed to send individual path components: the official linux client never sends portions of path containing the / character for example. Moreover, the 9P spec [2] also states that a system can decide to restrict the set of supported characters used in path components, with an explicit mention "to remove slashes from name components". This patch introduces a new name_is_illegal() helper that checks the names sent by the client are not empty and don't contain unwanted chars. Since 9pfs is only supported on linux hosts, only the / character is checked at the moment. When support for other hosts (AKA. win32) is added, other chars may need to be blacklisted as well. If a client sends an illegal path component, the request will fail and EINVAL is returned to the client. [1] http://man.cat-v.org/plan_9/5/walk [2] http://man.cat-v.org/plan_9/5/intro Suggested-by: Peter Maydell Signed-off-by: Greg Kurz --- hw/9pfs/9p.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c index b6b02b46a9da..dba11773699b 100644 --- a/hw/9pfs/9p.c +++ b/hw/9pfs/9p.c @@ -1256,6 +1256,11 @@ static int v9fs_walk_marshal(V9fsPDU *pdu, uint16_t nwnames, V9fsQID *qids) return offset; } +static bool name_is_illegal(const char *name) +{ + return name == NULL || strchr(name, '/') != NULL; +} + static void v9fs_walk(void *opaque) { int name_idx; @@ -1289,6 +1294,10 @@ static void v9fs_walk(void *opaque) if (err < 0) { goto out_nofid; } + if (name_is_illegal(wnames[i].data)) { + err = -EINVAL; + goto out_nofid; + } offset += err; } } else if (nwnames > P9_MAXWELEM) { @@ -1483,6 +1492,11 @@ static void v9fs_lcreate(void *opaque) } trace_v9fs_lcreate(pdu->tag, pdu->id, dfid, flags, mode, gid); + if (name_is_illegal(name.data)) { + err = -EINVAL; + goto out_nofid; + } + fidp = get_fid(pdu, dfid); if (fidp == NULL) { err = -ENOENT; @@ -2077,6 +2091,11 @@ static void v9fs_create(void *opaque) } trace_v9fs_create(pdu->tag, pdu->id, fid, name.data, perm, mode); + if (name_is_illegal(name.data)) { + err = -EINVAL; + goto out_nofid; + } + fidp = get_fid(pdu, fid); if (fidp == NULL) { err = -EINVAL; @@ -2242,6 +2261,11 @@ static void v9fs_symlink(void *opaque) } trace_v9fs_symlink(pdu->tag, pdu->id, dfid, name.data, symname.data, gid); + if (name_is_illegal(name.data) || name_is_illegal(symname.data)) { + err = -EINVAL; + goto out_nofid; + } + dfidp = get_fid(pdu, dfid); if (dfidp == NULL) { err = -EINVAL; @@ -2316,6 +2340,11 @@ static void v9fs_link(void *opaque) } trace_v9fs_link(pdu->tag, pdu->id, dfid, oldfid, name.data); + if (name_is_illegal(name.data)) { + err = -EINVAL; + goto out_nofid; + } + dfidp = get_fid(pdu, dfid); if (dfidp == NULL) { err = -ENOENT; @@ -2398,6 +2427,12 @@ static void v9fs_unlinkat(void *opaque) if (err < 0) { goto out_nofid; } + + if (name_is_illegal(name.data)) { + err = -EINVAL; + goto out_nofid; + } + dfidp = get_fid(pdu, dfid); if (dfidp == NULL) { err = -EINVAL; @@ -2504,6 +2539,12 @@ static void v9fs_rename(void *opaque) if (err < 0) { goto out_nofid; } + + if (name_is_illegal(name.data)) { + err = -EINVAL; + goto out_nofid; + } + fidp = get_fid(pdu, fid); if (fidp == NULL) { err = -ENOENT; @@ -2616,6 +2657,11 @@ static void v9fs_renameat(void *opaque) goto out_err; } + if (name_is_illegal(old_name.data) || name_is_illegal(new_name.data)) { + err = -EINVAL; + goto out_err; + } + v9fs_path_write_lock(s); err = v9fs_complete_renameat(pdu, olddirfid, &old_name, newdirfid, &new_name); @@ -2826,6 +2872,11 @@ static void v9fs_mknod(void *opaque) } trace_v9fs_mknod(pdu->tag, pdu->id, fid, mode, major, minor); + if (name_is_illegal(name.data)) { + err = -EINVAL; + goto out_nofid; + } + fidp = get_fid(pdu, fid); if (fidp == NULL) { err = -ENOENT; @@ -2977,6 +3028,11 @@ static void v9fs_mkdir(void *opaque) } trace_v9fs_mkdir(pdu->tag, pdu->id, fid, name.data, mode, gid); + if (name_is_illegal(name.data)) { + err = -EINVAL; + goto out_nofid; + } + fidp = get_fid(pdu, fid); if (fidp == NULL) { err = -ENOENT;