From patchwork Mon Feb 13 15:32:19 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andreas Gruenbacher X-Patchwork-Id: 9570137 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 AF31A60572 for ; Mon, 13 Feb 2017 15:43:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A6AF128173 for ; Mon, 13 Feb 2017 15:43:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9B72028356; Mon, 13 Feb 2017 15:43:10 +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=unavailable 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 4862128173 for ; Mon, 13 Feb 2017 15:43:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753358AbdBMPdI (ORCPT ); Mon, 13 Feb 2017 10:33:08 -0500 Received: from mx1.redhat.com ([209.132.183.28]:44368 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753302AbdBMPcz (ORCPT ); Mon, 13 Feb 2017 10:32:55 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 24C486AAC7; Mon, 13 Feb 2017 15:32:56 +0000 (UTC) Received: from nux.redhat.com (ovpn-117-141.ams2.redhat.com [10.36.117.141]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v1DFWd4N006129; Mon, 13 Feb 2017 10:32:52 -0500 From: Andreas Gruenbacher To: Alexander Viro Cc: Andreas Gruenbacher , Christoph Hellwig , "Theodore Ts'o" , Andreas Dilger , "J. Bruce Fields" , Jeff Layton , Trond Myklebust , Anna Schumaker , Dave Chinner , linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, linux-api@vger.kernel.org Subject: [PATCH v28 03/21] vfs: Add MAY_DELETE_SELF and MAY_DELETE_CHILD permission flags Date: Mon, 13 Feb 2017 16:32:19 +0100 Message-Id: <1486999957-2381-4-git-send-email-agruenba@redhat.com> In-Reply-To: <1486999957-2381-1-git-send-email-agruenba@redhat.com> References: <1486999957-2381-1-git-send-email-agruenba@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Mon, 13 Feb 2017 15:32:56 +0000 (UTC) Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Normally, deleting a file requires MAY_WRITE access to the parent directory. With richacls, a file may be deleted with MAY_DELETE_CHILD access to the parent directory or with MAY_DELETE_SELF access to the file. To support that, pass the MAY_DELETE_CHILD mask flag to inode_permission() when checking for delete access inside a directory, and MAY_DELETE_SELF when checking for delete access to a file itself. In case we have MAY_DELETE_SELF access on a file, we still need to perform non-file-permission related checks (LSM, immutability, etc.). Use the mask flags (MAY_WRITE | MAY_DELETE_CHILD | MAY_DELETE_SELF) for that; the combination of MAY_DELETE_CHILD and MAY_DELETE_SELF isn't otherwise useful. The MAY_DELETE_SELF permission overrides the sticky directory check. Signed-off-by: Andreas Gruenbacher Reviewed-by: J. Bruce Fields Reviewed-by: Steve French Reviewed-by: Jeff Layton --- fs/namei.c | 18 ++++++++++++------ include/linux/fs.h | 2 ++ 2 files changed, 14 insertions(+), 6 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 4cc7064..ba91d8f 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -463,9 +463,9 @@ static int sb_permission(struct super_block *sb, struct inode *inode, int mask) * this, letting us set arbitrary permissions for filesystem access without * changing the "normal" UIDs which are used for other things. * - * MAY_WRITE must be set in @mask whenever MAY_APPEND, MAY_CREATE_FILE, or - * MAY_CREATE_DIR are set. That way, file systems that don't support these - * permissions will check for MAY_WRITE instead. + * MAY_WRITE must be set in @mask whenever MAY_APPEND, MAY_CREATE_FILE, + * MAY_CREATE_DIR, or MAY_DELETE_CHILD are set. That way, file systems that + * don't support these permissions will check for MAY_WRITE instead. */ int inode_permission(struct inode *inode, int mask) { @@ -2747,14 +2747,20 @@ static int may_delete_or_replace(struct inode *dir, struct dentry *victim, BUG_ON(victim->d_parent->d_inode != dir); audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE); - error = inode_permission(dir, mask); + error = inode_permission(dir, mask | MAY_DELETE_CHILD); + if (!error && check_sticky(dir, inode)) + error = -EPERM; + if (error && IS_RICHACL(inode) && + inode_permission(inode, MAY_DELETE_SELF) == 0 && + inode_permission(dir, mask | MAY_DELETE_CHILD | MAY_DELETE_SELF) == 0) + error = 0; if (error) return error; if (IS_APPEND(dir)) return -EPERM; - if (check_sticky(dir, inode) || IS_APPEND(inode) || - IS_IMMUTABLE(inode) || IS_SWAPFILE(inode) || HAS_UNMAPPED_ID(inode)) + if (IS_APPEND(inode) || IS_IMMUTABLE(inode) || + IS_SWAPFILE(inode) || HAS_UNMAPPED_ID(inode)) return -EPERM; if (isdir) { if (!d_is_dir(victim)) diff --git a/include/linux/fs.h b/include/linux/fs.h index 7141760..b495b6c 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -86,6 +86,8 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset, #define MAY_NOT_BLOCK 0x00000080 #define MAY_CREATE_FILE 0x00000100 #define MAY_CREATE_DIR 0x00000200 +#define MAY_DELETE_CHILD 0x00000400 +#define MAY_DELETE_SELF 0x00000800 /* * flags in file.f_mode. Note that FMODE_READ and FMODE_WRITE must correspond