From patchwork Fri Apr 3 01:56:13 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Eric W. Biederman" X-Patchwork-Id: 6153201 Return-Path: X-Original-To: patchwork-linux-fsdevel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 39BB8BF4A6 for ; Fri, 3 Apr 2015 02:00:47 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 58C6320379 for ; Fri, 3 Apr 2015 02:00:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6A16F2035E for ; Fri, 3 Apr 2015 02:00:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753346AbbDCCAo (ORCPT ); Thu, 2 Apr 2015 22:00:44 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:56007 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753264AbbDCCAn (ORCPT ); Thu, 2 Apr 2015 22:00:43 -0400 Received: from in01.mta.xmission.com ([166.70.13.51]) by out02.mta.xmission.com with esmtps (TLS1.2:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.82) (envelope-from ) id 1YdquY-00027D-3V; Thu, 02 Apr 2015 20:00:42 -0600 Received: from 70-59-163-10.omah.qwest.net ([70.59.163.10] helo=x220.int.ebiederm.org) by in01.mta.xmission.com with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.82) (envelope-from ) id 1YdquX-0003Lp-Fw; Thu, 02 Apr 2015 20:00:41 -0600 From: "Eric W. Biederman" To: Linux Containers Cc: , "Serge E. Hallyn" , Andy Lutomirski , Richard Weinberger , Andrey Vagin , Al Viro , Jann Horn , Willy Tarreau , Omar Sandoval Date: Thu, 2 Apr 2015 20:56:13 -0500 Message-Id: <1428026183-14879-9-git-send-email-ebiederm@xmission.com> X-Mailer: git-send-email 2.2.1 In-Reply-To: <87a8yqou41.fsf_-_@x220.int.ebiederm.org> References: <87a8yqou41.fsf_-_@x220.int.ebiederm.org> X-XM-AID: U2FsdGVkX1/8Kru2mISi/th7FptSaHdcwcRK4jkRl60= X-SA-Exim-Connect-IP: 70.59.163.10 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-DCC: XMission; sa07 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Linux Containers X-Spam-Relay-Country: X-Spam-Timing: total 229 ms - load_scoreonly_sql: 0.09 (0.0%), signal_user_changed: 4.1 (1.8%), b_tie_ro: 2.8 (1.2%), parse: 0.81 (0.4%), extract_message_metadata: 12 (5.0%), get_uri_detail_list: 1.06 (0.5%), tests_pri_-1000: 6 (2.7%), tests_pri_-950: 1.32 (0.6%), tests_pri_-900: 1.09 (0.5%), tests_pri_-400: 18 (7.8%), check_bayes: 17 (7.3%), b_tokenize: 4.9 (2.1%), b_tok_get_all: 6 (2.5%), b_comp_prob: 1.59 (0.7%), b_tok_touch_all: 2.5 (1.1%), b_finish: 0.64 (0.3%), tests_pri_0: 178 (77.7%), tests_pri_500: 5 (2.2%), rewrite_mail: 0.00 (0.0%) Subject: [PATCH review 09/19] mnt: Fail collect_mounts when applied to unmounted mounts X-SA-Exim-Version: 4.2.1 (built Wed, 24 Sep 2014 11:00:52 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The only users of collect_mounts are in audit_tree.c In audit_tree_trees and audit_add_tree rule the path passed into collect_mounts is generated from kern_path passed an audit_tree pathname which is guaranteed to be an absolute path. In those cases collect_mounts is obviously intended to work on mounted paths and if a race results in paths that are unmounted when collect_mounts it is reasonable to fail early. The paths passed into audit_tag_tree don't have the absolute path check. But are used to play with fsnotify and otherwise interact with the audit_trees, so again operating only on mounted paths appears reasonable. Avoid having to worry about what happens when we try and audit unmounted filesystems by restricting collect_mounts to mounts that appear in the mount tree. Signed-off-by: "Eric W. Biederman" --- fs/namespace.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index 2b12b7a9455d..acc5583764dc 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1669,8 +1669,11 @@ struct vfsmount *collect_mounts(struct path *path) { struct mount *tree; namespace_lock(); - tree = copy_tree(real_mount(path->mnt), path->dentry, - CL_COPY_ALL | CL_PRIVATE); + if (!check_mnt(real_mount(path->mnt))) + tree = ERR_PTR(-EINVAL); + else + tree = copy_tree(real_mount(path->mnt), path->dentry, + CL_COPY_ALL | CL_PRIVATE); namespace_unlock(); if (IS_ERR(tree)) return ERR_CAST(tree);