From nobody Thu Nov 6 20:10:02 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 1488149555981583.4197246326361; Sun, 26 Feb 2017 14:52:35 -0800 (PST) Received: from localhost ([::1]:48788 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ci7gA-0004oc-F4 for importer@patchew.org; Sun, 26 Feb 2017 17:52:34 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50715) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ci7XU-00063V-Un for qemu-devel@nongnu.org; Sun, 26 Feb 2017 17:43:40 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ci7XR-0002yC-Sh for qemu-devel@nongnu.org; Sun, 26 Feb 2017 17:43:37 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:45009) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ci7XR-0002xv-IZ for qemu-devel@nongnu.org; Sun, 26 Feb 2017 17:43:33 -0500 Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v1QMcQvh120680 for ; Sun, 26 Feb 2017 17:43:32 -0500 Received: from e37.co.us.ibm.com (e37.co.us.ibm.com [32.97.110.158]) by mx0a-001b2d01.pphosted.com with ESMTP id 28u6wa43h9-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Sun, 26 Feb 2017 17:43:32 -0500 Received: from localhost by e37.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Sun, 26 Feb 2017 15:43:28 -0700 Received: from b01cxnp22036.gho.pok.ibm.com (b01cxnp22036.gho.pok.ibm.com [9.57.198.26]) by d03dlp03.boulder.ibm.com (Postfix) with ESMTP id 7C70319D801C; Sun, 26 Feb 2017 15:42:39 -0700 (MST) Received: from b01ledav002.gho.pok.ibm.com (b01ledav002.gho.pok.ibm.com [9.57.199.107]) by b01cxnp22036.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v1QMhRpJ55050460; Sun, 26 Feb 2017 22:43:27 GMT Received: from b01ledav002.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id DAC26124049; Sun, 26 Feb 2017 17:43:25 -0500 (EST) Received: from [192.168.66.23] (unknown [9.164.183.34]) by b01ledav002.gho.pok.ibm.com (Postfix) with ESMTP id A1AD012403F; Sun, 26 Feb 2017 17:43:24 -0500 (EST) From: Greg Kurz To: qemu-devel@nongnu.org Date: Sun, 26 Feb 2017 23:43:25 +0100 In-Reply-To: <148814889214.28146.16915712763478774662.stgit@bahia> References: <148814889214.28146.16915712763478774662.stgit@bahia> User-Agent: StGit/0.17.1-20-gc0b1b-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 17022622-0024-0000-0000-0000160107F4 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00006689; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000204; SDB=6.00827424; UDB=6.00405424; IPR=6.00604940; BA=6.00005172; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00014449; XFM=3.00000011; UTC=2017-02-26 22:43:31 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17022622-0025-0000-0000-000049121BBF Message-Id: <148814900509.28146.10314330961409823173.stgit@bahia> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-02-26_11:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=3 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1612050000 definitions=main-1702260233 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] [fuzzy] X-Received-From: 148.163.156.1 Subject: [Qemu-devel] [PATCH v2 14/28] 9pfs: local: statfs: don't follow symlinks 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: Jann Horn , Prasad J Pandit , Greg Kurz , "Aneesh Kumar K.V" , Stefan Hajnoczi Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 The local_statfs() callback is vulnerable to symlink attacks because it calls statfs() which follows symbolic links in all path elements. This patch converts local_statfs() to rely on open_nofollow() and fstatfs() instead. This partly fixes CVE-2016-9602. Signed-off-by: Greg Kurz Reviewed-by: Stefan Hajnoczi --- hw/9pfs/9p-local.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c index 9b2069f9120e..e88426dfebe5 100644 --- a/hw/9pfs/9p-local.c +++ b/hw/9pfs/9p-local.c @@ -1077,13 +1077,11 @@ static int local_fsync(FsContext *ctx, int fid_type, =20 static int local_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *st= buf) { - char *buffer; - int ret; - char *path =3D fs_path->data; + int fd, ret; =20 - buffer =3D rpath(s, path); - ret =3D statfs(buffer, stbuf); - g_free(buffer); + fd =3D local_open_nofollow(s, fs_path->data, O_RDONLY, 0); + ret =3D fstatfs(fd, stbuf); + close_preserve_errno(fd); return ret; } =20