From patchwork Thu Jan 21 13:19:39 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 12036607 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=-16.8 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 0C55AC433E9 for ; Thu, 21 Jan 2021 15:21:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B3DA823A03 for ; Thu, 21 Jan 2021 15:21:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732826AbhAUPUz (ORCPT ); Thu, 21 Jan 2021 10:20:55 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:54651 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732219AbhAUN0O (ORCPT ); Thu, 21 Jan 2021 08:26:14 -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 1l2Zu9-0005g7-Nn; Thu, 21 Jan 2021 13:21:41 +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?= , Linus Torvalds , 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-xfs@vger.kernel.org, linux-integrity@vger.kernel.org, selinux@vger.kernel.org, Christian Brauner Subject: [PATCH v6 20/40] init: handle idmapped mounts Date: Thu, 21 Jan 2021 14:19:39 +0100 Message-Id: <20210121131959.646623-21-christian.brauner@ubuntu.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210121131959.646623-1-christian.brauner@ubuntu.com> References: <20210121131959.646623-1-christian.brauner@ubuntu.com> MIME-Version: 1.0 X-Patch-Hashes: v=1; h=sha256; i=K1Mmb+2iBnpojBmIU4SJaafXPX8O2CFx1CDw+utpuOU=; m=S5fr/22/m+WbOwFrUpUHXheqOF01JiKNUA5zB/hY/Is=; p=MZSdRyOX771MwH+GLlcjB+0DrEr2A+58o5/RX/qOHFw=; g=45d6fad6f6d32f07d4014060b83492f4e5803561 X-Patch-Sig: m=pgp; i=christian.brauner@ubuntu.com; s=0x0x91C61BC06578DCA2; b=iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCYAl9pQAKCRCRxhvAZXjcovuOAQD0vz6 qwrpIJ0cuKYpZaxNYnIKAkRlsiy3S2ImpIjxs5wEAx6MHynYZhSK9hn2FPNdNgboF6ArU1F+IBR0A AU0LGgo= Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@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. Link: https://lore.kernel.org/r/20210112220124.837960-29-christian.brauner@ubuntu.com Cc: Christoph Hellwig Cc: David Howells Cc: Al Viro Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner Reviewed-by: Christoph Hellwig --- /* v2 */ patch introduced /* v3 */ unchanged /* v4 */ unchanged /* v5 */ unchanged base-commit: 7c53f6b671f4aba70ff15e1b05148b10d58c2837 /* v6 */ base-commit: 19c329f6808995b142b3966301f217c831e7cf31 - Christoph Hellwig : - Use new path_permission() helper. --- fs/init.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/fs/init.c b/fs/init.c index e65452750fa5..5c36adaa9b44 100644 --- a/fs/init.c +++ b/fs/init.c @@ -157,8 +157,8 @@ 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; } @@ -167,6 +167,7 @@ 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); @@ -181,14 +182,15 @@ 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: @@ -207,8 +209,8 @@ 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; } @@ -231,8 +233,8 @@ 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; }