From mboxrd@z Thu Jan 1 00:00:00 1970 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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 A6B4CC2BA83 for ; Fri, 14 Feb 2020 18:40:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8356B222C2 for ; Fri, 14 Feb 2020 18:40:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730442AbgBNSkq (ORCPT ); Fri, 14 Feb 2020 13:40:46 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:33837 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729781AbgBNSkp (ORCPT ); Fri, 14 Feb 2020 13:40:45 -0500 Received: from ip5f5bf7ec.dynamic.kabel-deutschland.de ([95.91.247.236] 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 1j2fqj-0000uO-8o; Fri, 14 Feb 2020 18:38:01 +0000 From: Christian Brauner To: =?UTF-8?q?St=C3=A9phane=20Graber?= , "Eric W. Biederman" , Aleksa Sarai , Jann Horn Cc: smbarber@chromium.org, Seth Forshee , Alexander Viro , Alexey Dobriyan , Serge Hallyn , James Morris , Kees Cook , Jonathan Corbet , Phil Estes , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, containers@lists.linux-foundation.org, linux-security-module@vger.kernel.org, linux-api@vger.kernel.org, Christian Brauner Subject: [PATCH v2 22/28] attr: notify_change(): handle fsid mappings Date: Fri, 14 Feb 2020 19:35:48 +0100 Message-Id: <20200214183554.1133805-23-christian.brauner@ubuntu.com> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200214183554.1133805-1-christian.brauner@ubuntu.com> References: <20200214183554.1133805-1-christian.brauner@ubuntu.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Switch notify_change() to lookup fsids in the fsid mappings. If no fsid mappings are setup the behavior is unchanged, i.e. fsids are looked up in the id mappings. Filesystems that share a superblock in all user namespaces they are mounted in will retain their old semantics even with the introduction of fsidmappings. Signed-off-by: Christian Brauner --- /* v2 */ unchanged --- fs/attr.c | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-) diff --git a/fs/attr.c b/fs/attr.c index b4bbdbd4c8ca..b3fe9d9582d2 100644 --- a/fs/attr.c +++ b/fs/attr.c @@ -17,6 +17,8 @@ #include #include #include +#include +#include static bool chown_ok(const struct inode *inode, kuid_t uid) { @@ -310,12 +312,21 @@ int notify_change(struct dentry * dentry, struct iattr * attr, struct inode **de * Verify that uid/gid changes are valid in the target * namespace of the superblock. */ - if (ia_valid & ATTR_UID && - !kuid_has_mapping(inode->i_sb->s_user_ns, attr->ia_uid)) - return -EOVERFLOW; - if (ia_valid & ATTR_GID && - !kgid_has_mapping(inode->i_sb->s_user_ns, attr->ia_gid)) - return -EOVERFLOW; + if (is_userns_visible(inode->i_sb->s_iflags)) { + if (ia_valid & ATTR_UID && + !kuid_has_mapping(inode->i_sb->s_user_ns, attr->ia_uid)) + return -EOVERFLOW; + if (ia_valid & ATTR_GID && + !kgid_has_mapping(inode->i_sb->s_user_ns, attr->ia_gid)) + return -EOVERFLOW; + } else { + if (ia_valid & ATTR_UID && + !kfsuid_has_mapping(inode->i_sb->s_user_ns, attr->ia_uid)) + return -EOVERFLOW; + if (ia_valid & ATTR_GID && + !kfsgid_has_mapping(inode->i_sb->s_user_ns, attr->ia_gid)) + return -EOVERFLOW; + } /* Don't allow modifications of files with invalid uids or * gids unless those uids & gids are being made valid. -- 2.25.0