From patchwork Thu Apr 27 18:23:59 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bill O'Donnell X-Patchwork-Id: 9703331 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 B5A2C601D3 for ; Thu, 27 Apr 2017 18:24:07 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AE91428652 for ; Thu, 27 Apr 2017 18:24:07 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A1C9628655; Thu, 27 Apr 2017 18:24:07 +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 vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 39BCB28652 for ; Thu, 27 Apr 2017 18:24:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966991AbdD0SYG (ORCPT ); Thu, 27 Apr 2017 14:24:06 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58188 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965785AbdD0SYF (ORCPT ); Thu, 27 Apr 2017 14:24:05 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 5730DC04BD44 for ; Thu, 27 Apr 2017 18:24:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 5730DC04BD44 Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=billodo@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 5730DC04BD44 Received: from localhost.localdomain.com (ovpn-122-194.rdu2.redhat.com [10.10.122.194]) by smtp.corp.redhat.com (Postfix) with ESMTP id 09793176A6 for ; Thu, 27 Apr 2017 18:24:04 +0000 (UTC) From: Bill O'Donnell To: linux-xfs@vger.kernel.org Subject: [PATCH v4] xfs_growfs: ensure target path is an active xfs mountpoint Date: Thu, 27 Apr 2017 13:23:59 -0500 Message-Id: <20170427182359.24314-1-billodo@redhat.com> In-Reply-To: <20170407175809.8540-1-billodo@redhat.com> References: <20170407175809.8540-1-billodo@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Thu, 27 Apr 2017 18:24:05 +0000 (UTC) Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP xfs_growfs manpage clearly states that the target path must be an active xfs mountpoint. Current behavior allows xfs_growfs to proceed if the target path resides anywhere on a mounted xfs filesystem. This could lead to unexpected results. Unless the target path is an active xfs mountpoint, reject it. Create a new fs table lookup function which matches only active xfs mount points, not any file residing within those mountpoints. Signed-off-by: Bill O'Donnell Reviewed-by: Eric Sandeen --- v4: improve commit message and subject line. Further improvement of error message for realpath() prior to table lookup in xfs_growfs. v3: improve error message for realpath failure. Add comments to better document the differences between fs_table_lookup() and fs_table_lookup_mount(). Use realpath() in fs_table_lookup_mount() prior to directory comparison. v2: in order to properly handle relative pathnames, symlinks, and bind-mounts, use realpath to establish canonical path name. This also requires the introduction of a lookup function based on the target mountpoint. growfs/xfs_growfs.c | 10 +++++++++- include/path.h | 1 + libxcmd/paths.c | 31 +++++++++++++++++++++++++++++++ 3 files changed, 41 insertions(+), 1 deletion(-) diff --git a/growfs/xfs_growfs.c b/growfs/xfs_growfs.c index a294e14..366176b 100644 --- a/growfs/xfs_growfs.c +++ b/growfs/xfs_growfs.c @@ -133,6 +133,7 @@ main(int argc, char **argv) int spinodes; int rmapbt_enabled; int reflink_enabled; + char rpath[PATH_MAX]; progname = basename(argv[0]); setlocale(LC_ALL, ""); @@ -202,7 +203,14 @@ main(int argc, char **argv) aflag = 1; fs_table_initialise(0, NULL, 0, NULL); - fs = fs_table_lookup(argv[optind], FS_MOUNT_POINT); + + if (!realpath(argv[optind], rpath)) { + fprintf(stderr, _("%s: path resolution failed for %s: %s\n"), + progname, argv[optind], strerror(errno)); + return 1; + } + + fs = fs_table_lookup_mount(rpath); if (!fs) { fprintf(stderr, _("%s: %s is not a mounted XFS filesystem\n"), progname, argv[optind]); diff --git a/include/path.h b/include/path.h index d077bac..1d3a902 100644 --- a/include/path.h +++ b/include/path.h @@ -56,6 +56,7 @@ extern void fs_table_insert_project_path(char *__dir, uint __projid); extern fs_path_t *fs_table_lookup(const char *__dir, uint __flags); +extern fs_path_t *fs_table_lookup_mount(const char *__dir); typedef struct fs_cursor { uint count; /* total count of mount entries */ diff --git a/libxcmd/paths.c b/libxcmd/paths.c index 816acc2..b767e9d 100644 --- a/libxcmd/paths.c +++ b/libxcmd/paths.c @@ -65,6 +65,9 @@ fs_device_number( * Find the FS table entry for the given path. The "flags" argument * is a mask containing FS_MOUNT_POINT or FS_PROJECT_PATH (or both) * to indicate the type of table entry sought. + * fs_table_lookup() finds the fs table entry for the filesystem hosting + * the file represented in the "dir" argument. To compare against actual + * mount point entries, use fs_table_lookup_mount() instead. */ struct fs_path * fs_table_lookup( @@ -86,6 +89,34 @@ fs_table_lookup( return NULL; } +/* + * Find the FS table entry describing an actual mount for the given path. + * Unlike fs_table_lookup(), fs_table_lookup_mount() compares the "dir" + * argument to actual mount point entries in the table. Accordingly, it + * will find matches only if the "dir" argument is indeed mounted. + */ +struct fs_path * +fs_table_lookup_mount( + const char *dir) +{ + uint i; + dev_t dev = 0; + char rpath[PATH_MAX]; + + if (fs_device_number(dir, &dev)) + return NULL; + + for (i = 0; i < fs_count; i++) { + if (fs_table[i].fs_flags != FS_MOUNT_POINT) + continue; + if (!realpath(fs_table[i].fs_dir, rpath)) + continue; + if (strcmp(rpath, dir) == 0) + return &fs_table[i]; + } + return NULL; +} + static int fs_table_insert( char *dir,