From patchwork Thu Dec 3 23:57:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 11950219 X-Patchwork-Delegate: paul@paul-moore.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 56078C4361A for ; Fri, 4 Dec 2020 00:10:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1361E22224 for ; Fri, 4 Dec 2020 00:10:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389521AbgLDAKo (ORCPT ); Thu, 3 Dec 2020 19:10:44 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:42836 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726619AbgLDAKn (ORCPT ); Thu, 3 Dec 2020 19:10:43 -0500 Received: from ip5f5af0a0.dynamic.kabel-deutschland.de ([95.90.240.160] helo=wittgenstein.fritz.box) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1kkyY0-0007ka-3F; Fri, 04 Dec 2020 00:02:04 +0000 From: Christian Brauner To: Alexander Viro , Christoph Hellwig , linux-fsdevel@vger.kernel.org Cc: John Johansen , James Morris , Mimi Zohar , Dmitry Kasatkin , Stephen Smalley , Casey Schaufler , Arnd Bergmann , Andreas Dilger , OGAWA Hirofumi , Geoffrey Thomas , Mrunal Patel , Josh Triplett , Andy Lutomirski , Theodore Tso , Alban Crequy , Tycho Andersen , David Howells , James Bottomley , Seth Forshee , =?utf-8?q?St=C3=A9phane_Graber?= , Aleksa Sarai , Lennart Poettering , "Eric W. Biederman" , smbarber@chromium.org, Phil Estes , Serge Hallyn , Kees Cook , Todd Kjos , Paul Moore , Jonathan Corbet , containers@lists.linux-foundation.org, linux-security-module@vger.kernel.org, linux-api@vger.kernel.org, linux-ext4@vger.kernel.org, linux-integrity@vger.kernel.org, selinux@vger.kernel.org, Christian Brauner , Christoph Hellwig Subject: [PATCH v4 27/40] init: handle idmapped mounts Date: Fri, 4 Dec 2020 00:57:23 +0100 Message-Id: <20201203235736.3528991-28-christian.brauner@ubuntu.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201203235736.3528991-1-christian.brauner@ubuntu.com> References: <20201203235736.3528991-1-christian.brauner@ubuntu.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: selinux@vger.kernel.org Enable the init helpers to handle idmapped mounts by passing down the mount's user namespace. If the initial user namespace is passed nothing changes so non-idmapped mounts will see identical behavior as before. Cc: Christoph Hellwig Cc: David Howells Cc: Al Viro Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner --- /* v2 */ patch introduced /* v3 */ unchanged /* v4 */ unchanged --- fs/init.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/fs/init.c b/fs/init.c index 06d8e52ce18e..1db2b392e4e6 100644 --- a/fs/init.c +++ b/fs/init.c @@ -49,7 +49,7 @@ int __init init_chdir(const char *filename) error = kern_path(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); if (error) return error; - error = inode_permission(&init_user_ns, path.dentry->d_inode, + error = inode_permission(mnt_user_ns(path.mnt), path.dentry->d_inode, MAY_EXEC | MAY_CHDIR); if (!error) set_fs_pwd(current->fs, &path); @@ -65,7 +65,7 @@ int __init init_chroot(const char *filename) error = kern_path(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); if (error) return error; - error = inode_permission(&init_user_ns, path.dentry->d_inode, + error = inode_permission(mnt_user_ns(path.mnt), path.dentry->d_inode, MAY_EXEC | MAY_CHDIR); if (error) goto dput_and_out; @@ -120,7 +120,7 @@ int __init init_eaccess(const char *filename) error = kern_path(filename, LOOKUP_FOLLOW, &path); if (error) return error; - error = inode_permission(&init_user_ns, d_inode(path.dentry), + error = inode_permission(mnt_user_ns(path.mnt), d_inode(path.dentry), MAY_ACCESS); path_put(&path); return error; @@ -160,8 +160,8 @@ int __init init_mknod(const char *filename, umode_t mode, unsigned int dev) mode &= ~current_umask(); error = security_path_mknod(&path, dentry, mode, dev); if (!error) - error = vfs_mknod(&init_user_ns, path.dentry->d_inode, dentry, - mode, new_decode_dev(dev)); + error = vfs_mknod(mnt_user_ns(path.mnt), path.dentry->d_inode, + dentry, mode, new_decode_dev(dev)); done_path_create(&path, dentry); return error; } @@ -170,6 +170,7 @@ int __init init_link(const char *oldname, const char *newname) { struct dentry *new_dentry; struct path old_path, new_path; + struct user_namespace *mnt_userns; int error; error = kern_path(oldname, 0, &old_path); @@ -184,14 +185,15 @@ int __init init_link(const char *oldname, const char *newname) error = -EXDEV; if (old_path.mnt != new_path.mnt) goto out_dput; - error = may_linkat(&init_user_ns, &old_path); + mnt_userns = mnt_user_ns(new_path.mnt); + error = may_linkat(mnt_userns, &old_path); if (unlikely(error)) goto out_dput; error = security_path_link(old_path.dentry, &new_path, new_dentry); if (error) goto out_dput; - error = vfs_link(old_path.dentry, &init_user_ns, - new_path.dentry->d_inode, new_dentry, NULL); + error = vfs_link(old_path.dentry, mnt_userns, new_path.dentry->d_inode, + new_dentry, NULL); out_dput: done_path_create(&new_path, new_dentry); out: @@ -210,7 +212,8 @@ int __init init_symlink(const char *oldname, const char *newname) return PTR_ERR(dentry); error = security_path_symlink(&path, dentry, oldname); if (!error) - error = vfs_symlink(&init_user_ns, path.dentry->d_inode, dentry, oldname); + error = vfs_symlink(mnt_user_ns(path.mnt), path.dentry->d_inode, + dentry, oldname); done_path_create(&path, dentry); return error; } @@ -233,7 +236,8 @@ int __init init_mkdir(const char *pathname, umode_t mode) mode &= ~current_umask(); error = security_path_mkdir(&path, dentry, mode); if (!error) - error = vfs_mkdir(&init_user_ns, path.dentry->d_inode, dentry, mode); + error = vfs_mkdir(mnt_user_ns(path.mnt), path.dentry->d_inode, + dentry, mode); done_path_create(&path, dentry); return error; }