From nobody Thu Nov 6 18:52:25 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 1488237968105977.1184184310537; Mon, 27 Feb 2017 15:26:08 -0800 (PST) Received: from localhost ([::1]:57556 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ciUg9-00052n-Gy for importer@patchew.org; Mon, 27 Feb 2017 18:26:05 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47051) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ciUHr-0000fQ-TS for qemu-devel@nongnu.org; Mon, 27 Feb 2017 18:01:01 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ciUHq-00047T-OI for qemu-devel@nongnu.org; Mon, 27 Feb 2017 18:01:00 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:36986) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ciUHq-00046Y-FD for qemu-devel@nongnu.org; Mon, 27 Feb 2017 18:00:58 -0500 Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v1RMrjeG004766 for ; Mon, 27 Feb 2017 18:00:57 -0500 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0a-001b2d01.pphosted.com with ESMTP id 28vpur1hp4-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 27 Feb 2017 18:00:56 -0500 Received: from localhost by e06smtp07.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Mon, 27 Feb 2017 23:00:50 -0000 Received: from b06cxnps3074.portsmouth.uk.ibm.com (d06relay09.portsmouth.uk.ibm.com [9.149.109.194]) by d06dlp02.portsmouth.uk.ibm.com (Postfix) with ESMTP id 788522190063; Mon, 27 Feb 2017 22:59:51 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v1RN0ovC6816054; Mon, 27 Feb 2017 23:00:50 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9D2F2A4059; Mon, 27 Feb 2017 23:00:46 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8A6EFA404D; Mon, 27 Feb 2017 23:00:46 +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; Mon, 27 Feb 2017 23:00:46 +0000 (GMT) Received: from bahia.lan (icon-9-164-183-34.megacenter.de.ibm.com [9.164.183.34]) by smtp.lab.toulouse-stg.fr.ibm.com (Postfix) with ESMTP id 78157220711; Tue, 28 Feb 2017 00:00:49 +0100 (CET) From: Greg Kurz To: qemu-devel@nongnu.org Date: Tue, 28 Feb 2017 00:00:12 +0100 X-Mailer: git-send-email 2.7.4 In-Reply-To: <1488236421-30983-1-git-send-email-groug@kaod.org> References: <1488236421-30983-1-git-send-email-groug@kaod.org> X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 17022723-0028-0000-0000-000002B2F609 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17022723-0029-0000-0000-000022860018 Message-Id: <1488236421-30983-23-git-send-email-groug@kaod.org> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-02-27_17:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=13 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1612050000 definitions=main-1702270213 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] [fuzzy] X-Received-From: 148.163.156.1 Subject: [Qemu-devel] [PULL 22/31] 9pfs: local: rename: use renameat 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 , "Aneesh Kumar K.V" , Greg Kurz 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" The local_rename() callback is vulnerable to symlink attacks because it uses rename() which follows symbolic links in all path elements but the rightmost one. This patch simply transforms local_rename() into a wrapper around local_renameat() which is symlink-attack safe. This partly fixes CVE-2016-9602. Signed-off-by: Greg Kurz Reviewed-by: Stefan Hajnoczi --- hw/9pfs/9p-local.c | 57 ++++++++++++++++++++++++++------------------------= ---- 1 file changed, 27 insertions(+), 30 deletions(-) diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c index cf9e03d8e64f..e7a7468a565b 100644 --- a/hw/9pfs/9p-local.c +++ b/hw/9pfs/9p-local.c @@ -964,36 +964,6 @@ static int local_truncate(FsContext *ctx, V9fsPath *fs= _path, off_t size) return ret; } =20 -static int local_rename(FsContext *ctx, const char *oldpath, - const char *newpath) -{ - int err; - char *buffer, *buffer1; - - if (ctx->export_flags & V9FS_SM_MAPPED_FILE) { - err =3D local_create_mapped_attr_dir(ctx, newpath); - if (err < 0) { - return err; - } - /* rename the .virtfs_metadata files */ - buffer =3D local_mapped_attr_path(ctx, oldpath); - buffer1 =3D local_mapped_attr_path(ctx, newpath); - err =3D rename(buffer, buffer1); - g_free(buffer); - g_free(buffer1); - if (err < 0 && errno !=3D ENOENT) { - return err; - } - } - - buffer =3D rpath(ctx, oldpath); - buffer1 =3D rpath(ctx, newpath); - err =3D rename(buffer, buffer1); - g_free(buffer); - g_free(buffer1); - return err; -} - static int local_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp) { char *buffer; @@ -1254,6 +1224,33 @@ out: return ret; } =20 +static void v9fs_path_init_dirname(V9fsPath *path, const char *str) +{ + path->data =3D g_path_get_dirname(str); + path->size =3D strlen(path->data) + 1; +} + +static int local_rename(FsContext *ctx, const char *oldpath, + const char *newpath) +{ + int err; + char *oname =3D g_path_get_basename(oldpath); + char *nname =3D g_path_get_basename(newpath); + V9fsPath olddir, newdir; + + v9fs_path_init_dirname(&olddir, oldpath); + v9fs_path_init_dirname(&newdir, newpath); + + err =3D local_renameat(ctx, &olddir, oname, &newdir, nname); + + v9fs_path_free(&newdir); + v9fs_path_free(&olddir); + g_free(nname); + g_free(oname); + + return err; +} + static int local_unlinkat(FsContext *ctx, V9fsPath *dir, const char *name, int flags) { --=20 2.7.4