From nobody Tue Nov 4 15:41:11 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.zohomail.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 1503966295575292.21890976700786; Mon, 28 Aug 2017 17:24:55 -0700 (PDT) Received: from localhost ([::1]:41922 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dmUKr-0000SQ-9h for importer@patchew.org; Mon, 28 Aug 2017 20:24:53 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47374) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dmUC7-0000r8-5L for qemu-devel@nongnu.org; Mon, 28 Aug 2017 20:15:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dmUC3-000553-7O for qemu-devel@nongnu.org; Mon, 28 Aug 2017 20:15:51 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:50495) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dmUC2-00054A-Uq for qemu-devel@nongnu.org; Mon, 28 Aug 2017 20:15:47 -0400 Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v7T0EDPc077706 for ; Mon, 28 Aug 2017 20:15:46 -0400 Received: from e14.ny.us.ibm.com (e14.ny.us.ibm.com [129.33.205.204]) by mx0a-001b2d01.pphosted.com with ESMTP id 2cmnx0yuc7-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 28 Aug 2017 20:15:45 -0400 Received: from localhost by e14.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Mon, 28 Aug 2017 20:15:42 -0400 Received: from b01ledav004.gho.pok.ibm.com (b01ledav004.gho.pok.ibm.com [9.57.199.109]) by b01cxnp22036.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v7T0FfC331457484; Tue, 29 Aug 2017 00:15:41 GMT Received: from b01ledav004.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id DF05111204B; Mon, 28 Aug 2017 20:15:27 -0400 (EDT) Received: from localhost (unknown [9.80.85.217]) by b01ledav004.gho.pok.ibm.com (Postfix) with ESMTP id B0C1D112034; Mon, 28 Aug 2017 20:15:27 -0400 (EDT) From: Michael Roth To: qemu-devel@nongnu.org Date: Mon, 28 Aug 2017 19:13:48 -0500 X-Mailer: git-send-email 2.7.4 In-Reply-To: <1503965694-10794-1-git-send-email-mdroth@linux.vnet.ibm.com> References: <1503965694-10794-1-git-send-email-mdroth@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17082900-0052-0000-0000-00000257331C X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007630; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000226; SDB=6.00909028; UDB=6.00455849; IPR=6.00689279; BA=6.00005557; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00016909; XFM=3.00000015; UTC=2017-08-29 00:15:43 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17082900-0053-0000-0000-000051D1D909 Message-Id: <1503965694-10794-14-git-send-email-mdroth@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-08-28_13:, , 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=8.0.1-1707230000 definitions=main-1708290001 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 13/79] 9pfs: local: fix unlink of alien files in mapped-file mode 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: qemu-stable@nongnu.org, 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" From: Greg Kurz When trying to remove a file from a directory, both created in non-mapped mode, the file remains and EBADF is returned to the guest. This is a regression introduced by commit "df4938a6651b 9pfs: local: unlinkat: don't follow symlinks" when fixing CVE-2016-9602. It changed the way we unlink the metadata file from ret =3D remove("$dir/.virtfs_metadata/$name"); if (ret < 0 && errno !=3D ENOENT) { /* Error out */ } /* Ignore absence of metadata */ to fd =3D openat("$dir/.virtfs_metadata") unlinkat(fd, "$name") if (ret < 0 && errno !=3D ENOENT) { /* Error out */ } /* Ignore absence of metadata */ If $dir was created in non-mapped mode, openat() fails with ENOENT and we pass -1 to unlinkat(), which fails in turn with EBADF. We just need to check the return of openat() and ignore ENOENT, in order to restore the behaviour we had with remove(). Signed-off-by: Greg Kurz Reviewed-by: Eric Blake [groug: rewrote the comments as suggested by Eric] (cherry picked from commit 6a87e7929f97b86c5823d4616fa1aa7636b2f116) Signed-off-by: Michael Roth --- hw/9pfs/9p-local.c | 34 +++++++++++++++------------------- 1 file changed, 15 insertions(+), 19 deletions(-) diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c index f3ebca4..7a0c383 100644 --- a/hw/9pfs/9p-local.c +++ b/hw/9pfs/9p-local.c @@ -957,6 +957,14 @@ static int local_unlinkat_common(FsContext *ctx, int d= irfd, const char *name, if (ctx->export_flags & V9FS_SM_MAPPED_FILE) { int map_dirfd; =20 + /* We need to remove the metadata as well: + * - the metadata directory if we're removing a directory + * - the metadata file in the parent's metadata directory + * + * If any of these are missing (ie, ENOENT) then we're probably + * trying to remove something that wasn't created in mapped-file + * mode. We just ignore the error. + */ if (flags =3D=3D AT_REMOVEDIR) { int fd; =20 @@ -964,32 +972,20 @@ static int local_unlinkat_common(FsContext *ctx, int = dirfd, const char *name, if (fd =3D=3D -1) { goto err_out; } - /* - * If directory remove .virtfs_metadata contained in the - * directory - */ ret =3D unlinkat(fd, VIRTFS_META_DIR, AT_REMOVEDIR); close_preserve_errno(fd); if (ret < 0 && errno !=3D ENOENT) { - /* - * We didn't had the .virtfs_metadata file. May be file cr= eated - * in non-mapped mode ?. Ignore ENOENT. - */ goto err_out; } } - /* - * Now remove the name from parent directory - * .virtfs_metadata directory. - */ map_dirfd =3D openat_dir(dirfd, VIRTFS_META_DIR); - ret =3D unlinkat(map_dirfd, name, 0); - close_preserve_errno(map_dirfd); - if (ret < 0 && errno !=3D ENOENT) { - /* - * We didn't had the .virtfs_metadata file. May be file created - * in non-mapped mode ?. Ignore ENOENT. - */ + if (map_dirfd !=3D -1) { + ret =3D unlinkat(map_dirfd, name, 0); + close_preserve_errno(map_dirfd); + if (ret < 0 && errno !=3D ENOENT) { + goto err_out; + } + } else if (errno !=3D ENOENT) { goto err_out; } } --=20 2.7.4