From patchwork Sun Sep 6 08:14:06 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andreas Gruenbacher X-Patchwork-Id: 7131161 Return-Path: X-Original-To: patchwork-linux-fsdevel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id E6E4D9F32B for ; Sun, 6 Sep 2015 08:15:01 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 463A520738 for ; Sun, 6 Sep 2015 08:15:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4113D2073D for ; Sun, 6 Sep 2015 08:14:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751972AbbIFIOi (ORCPT ); Sun, 6 Sep 2015 04:14:38 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51148 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751952AbbIFIOL (ORCPT ); Sun, 6 Sep 2015 04:14:11 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (Postfix) with ESMTPS id D8A49A3039; Sun, 6 Sep 2015 08:14:10 +0000 (UTC) Received: from nuc.home.com (vpn1-7-169.ams2.redhat.com [10.36.7.169]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t868E84u025440; Sun, 6 Sep 2015 04:14:09 -0400 From: Andreas Gruenbacher To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-api@vger.kernel.org, linux-cifs@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH] vfs: Add MAY_DELETE_SELF and MAY_DELETE_CHILD permission flags Date: Sun, 6 Sep 2015 10:14:06 +0200 Message-Id: <1441527246-18189-1-git-send-email-agruenba@redhat.com> In-Reply-To: <1441448856-13478-4-git-send-email-agruenba@redhat.com> References: <1441448856-13478-4-git-send-email-agruenba@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Spam-Status: No, score=-5.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, SUSPICIOUS_RECIPS, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP [This replaces v7 of this patch; MAY_DELETE_SELF now properly overrides the sticky check.] 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 itelf. The MAY_DELETE_SELF permission overrides the sticky directory check. Signed-off-by: Andreas Gruenbacher Reviewed-by: J. Bruce Fields --- fs/namei.c | 21 ++++++++++++--------- include/linux/fs.h | 2 ++ 2 files changed, 14 insertions(+), 9 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 428b4a6..1a3f0d8 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -453,9 +453,9 @@ 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) { @@ -2528,7 +2528,7 @@ static int may_delete(struct inode *dir, struct dentry *victim, bool isdir, bool replace) { struct inode *inode = d_backing_inode(victim); - int error, mask = MAY_WRITE | MAY_EXEC; + int error, mask = MAY_EXEC; if (d_is_negative(victim)) return -ENOENT; @@ -2538,15 +2538,18 @@ static int may_delete(struct inode *dir, struct dentry *victim, audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE); if (replace) - mask |= isdir ? MAY_CREATE_DIR : MAY_CREATE_FILE; - error = inode_permission(dir, mask); + mask |= MAY_WRITE | (isdir ? MAY_CREATE_DIR : MAY_CREATE_FILE); + error = inode_permission(dir, mask | MAY_WRITE | MAY_DELETE_CHILD); + if (!error && check_sticky(dir, inode)) + error = -EPERM; + if (error && IS_RICHACL(inode) && + inode_permission(inode, 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)) + if (IS_APPEND(inode) || IS_IMMUTABLE(inode) || IS_SWAPFILE(inode)) return -EPERM; if (isdir) { if (!d_is_dir(victim)) diff --git a/include/linux/fs.h b/include/linux/fs.h index b2f1b1b..99c95d1 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -84,6 +84,8 @@ typedef void (dax_iodone_t)(struct buffer_head *bh_map, int uptodate); #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