From patchwork Fri Mar 27 16:50:03 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Andreas_Gr=C3=BCnbacher?= X-Patchwork-Id: 6110691 Return-Path: X-Original-To: patchwork-linux-nfs@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 C42F79F399 for ; Fri, 27 Mar 2015 17:04:48 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id C140D203AD for ; Fri, 27 Mar 2015 17:04:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9E9542035E for ; Fri, 27 Mar 2015 17:04:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754717AbbC0REa (ORCPT ); Fri, 27 Mar 2015 13:04:30 -0400 Received: from mail-wi0-f177.google.com ([209.85.212.177]:37130 "EHLO mail-wi0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753861AbbC0Qvq (ORCPT ); Fri, 27 Mar 2015 12:51:46 -0400 Received: by wiaa2 with SMTP id a2so39189261wia.0; Fri, 27 Mar 2015 09:51:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:subject:date:message-id:in-reply-to:references:in-reply-to :references; bh=6tbrrQo3iBayzmpVynlxWtQ5I+PA6K/YvdlGKS+OEG8=; b=O7oUFUuU7eqhrmbVf8hbE/xD0uOhITKYclhw5katC1iP0INBx0b5BkvKKf5wpOus29 UfvNEmCVHBRNXF2awuaFql0Nur9KrvRmfTxxtCf/PguiHdLPOjqQDcW2pupDmkud9OOB /+IgtDs7oBZu4xMWkgXSqDdNIKQvDvEm4CgMMxsFDG4XUwa1VNLVkACEX2XC9zZnqUbZ 9WKdYJPLb2h7BWt9cGtTdcy9+a+TP9W3eq/XwT/kvIFEW8hhlPGxyyoBkE2IK3WlpwKC AHppWAWxDZKFEmtVAdILY7TlvSWHpfLQf7zJXrT+A2os3zNqJEpUiuOT4/RWRh9SmEQo 2Cmg== X-Received: by 10.180.74.112 with SMTP id s16mr57619688wiv.73.1427475104292; Fri, 27 Mar 2015 09:51:44 -0700 (PDT) Received: from nuc.home.com (80-110-94-70.cgn.dynamic.surfer.at. [80.110.94.70]) by mx.google.com with ESMTPSA id j7sm3592306wix.4.2015.03.27.09.51.42 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 27 Mar 2015 09:51:43 -0700 (PDT) From: Andreas Gruenbacher X-Google-Original-From: Andreas Gruenbacher To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org Subject: [RFC 05/39] vfs: Add MAY_CREATE_FILE and MAY_CREATE_DIR permission flags Date: Fri, 27 Mar 2015 17:50:03 +0100 Message-Id: <920552d15ee393b70fdcb0557c62a9336a2fb7df.1427471526.git.agruenba@redhat.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: References: In-Reply-To: References: Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Spam-Status: No, score=-6.8 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, T_DKIM_INVALID, T_RP_MATCHES_RCVD, 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 Richacls distinguish between creating non-directories and directories. To support that, add an isdir parameter to may_create(). When checking inode_permission() for create permission, pass in an additional MAY_CREATE_FILE or MAY_CREATE_DIR mask flag. To allow checking for delete *and* create access when replacing an existing file via vfs_rename(), add a replace parameter to may_delete(). Signed-off-by: Andreas Gruenbacher --- fs/namei.c | 42 ++++++++++++++++++++++++------------------ include/linux/fs.h | 2 ++ 2 files changed, 26 insertions(+), 18 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 0ba4bbc..a8bc030 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -454,7 +454,8 @@ 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. * - * When checking for MAY_APPEND, MAY_WRITE must also be set in @mask. + * When checking for MAY_APPEND, MAY_CREATE_FILE, MAY_CREATE_DIR, + * MAY_WRITE must also be set in @mask. */ int inode_permission(struct inode *inode, int mask) { @@ -2447,10 +2448,11 @@ EXPORT_SYMBOL(__check_sticky); * 10. We don't allow removal of NFS sillyrenamed files; it's handled by * nfs_async_unlink(). */ -static int may_delete(struct inode *dir, struct dentry *victim, bool isdir) +static int may_delete(struct inode *dir, struct dentry *victim, + bool isdir, bool replace) { struct inode *inode = victim->d_inode; - int error; + int error, mask = MAY_WRITE | MAY_EXEC; if (d_is_negative(victim)) return -ENOENT; @@ -2459,7 +2461,9 @@ static int may_delete(struct inode *dir, struct dentry *victim, bool isdir) BUG_ON(victim->d_parent->d_inode != dir); audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE); - error = inode_permission(dir, MAY_WRITE | MAY_EXEC); + if (replace) + mask |= isdir ? MAY_CREATE_DIR : MAY_CREATE_FILE; + error = inode_permission(dir, mask); if (error) return error; if (IS_APPEND(dir)) @@ -2490,14 +2494,16 @@ static int may_delete(struct inode *dir, struct dentry *victim, bool isdir) * 3. We should have write and exec permissions on dir * 4. We can't do it if dir is immutable (done in permission()) */ -static inline int may_create(struct inode *dir, struct dentry *child) +static inline int may_create(struct inode *dir, struct dentry *child, bool isdir) { + int mask = isdir ? MAY_CREATE_DIR : MAY_CREATE_FILE; + audit_inode_child(dir, child, AUDIT_TYPE_CHILD_CREATE); if (child->d_inode) return -EEXIST; if (IS_DEADDIR(dir)) return -ENOENT; - return inode_permission(dir, MAY_WRITE | MAY_EXEC); + return inode_permission(dir, MAY_WRITE | MAY_EXEC | mask); } /* @@ -2547,7 +2553,7 @@ EXPORT_SYMBOL(unlock_rename); int vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool want_excl) { - int error = may_create(dir, dentry); + int error = may_create(dir, dentry, false); if (error) return error; @@ -3422,7 +3428,7 @@ EXPORT_SYMBOL(user_path_create); int vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) { - int error = may_create(dir, dentry); + int error = may_create(dir, dentry, false); if (error) return error; @@ -3514,7 +3520,7 @@ SYSCALL_DEFINE3(mknod, const char __user *, filename, umode_t, mode, unsigned, d int vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) { - int error = may_create(dir, dentry); + int error = may_create(dir, dentry, true); unsigned max_links = dir->i_sb->s_max_links; if (error) @@ -3595,7 +3601,7 @@ EXPORT_SYMBOL(dentry_unhash); int vfs_rmdir(struct inode *dir, struct dentry *dentry) { - int error = may_delete(dir, dentry, 1); + int error = may_delete(dir, dentry, true, false); if (error) return error; @@ -3715,7 +3721,7 @@ SYSCALL_DEFINE1(rmdir, const char __user *, pathname) int vfs_unlink(struct inode *dir, struct dentry *dentry, struct inode **delegated_inode) { struct inode *target = dentry->d_inode; - int error = may_delete(dir, dentry, 0); + int error = may_delete(dir, dentry, false, false); if (error) return error; @@ -3847,7 +3853,7 @@ SYSCALL_DEFINE1(unlink, const char __user *, pathname) int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname) { - int error = may_create(dir, dentry); + int error = may_create(dir, dentry, false); if (error) return error; @@ -3930,7 +3936,7 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de if (!inode) return -ENOENT; - error = may_create(dir, new_dentry); + error = may_create(dir, new_dentry, false); if (error) return error; @@ -4118,19 +4124,19 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, if (source == target) return 0; - error = may_delete(old_dir, old_dentry, is_dir); + error = may_delete(old_dir, old_dentry, is_dir, false); if (error) return error; if (!target) { - error = may_create(new_dir, new_dentry); + error = may_create(new_dir, new_dentry, is_dir); } else { new_is_dir = d_is_dir(new_dentry); if (!(flags & RENAME_EXCHANGE)) - error = may_delete(new_dir, new_dentry, is_dir); + error = may_delete(new_dir, new_dentry, is_dir, true); else - error = may_delete(new_dir, new_dentry, new_is_dir); + error = may_delete(new_dir, new_dentry, new_is_dir, true); } if (error) return error; @@ -4394,7 +4400,7 @@ SYSCALL_DEFINE2(rename, const char __user *, oldname, const char __user *, newna int vfs_whiteout(struct inode *dir, struct dentry *dentry) { - int error = may_create(dir, dentry); + int error = may_create(dir, dentry, false); if (error) return error; diff --git a/include/linux/fs.h b/include/linux/fs.h index f64eb45..bbe1d26 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -80,6 +80,8 @@ typedef void (dio_iodone_t)(struct kiocb *iocb, loff_t offset, #define MAY_CHDIR 0x00000040 /* called from RCU mode, don't block */ #define MAY_NOT_BLOCK 0x00000080 +#define MAY_CREATE_FILE 0x00000100 +#define MAY_CREATE_DIR 0x00000200 /* * flags in file.f_mode. Note that FMODE_READ and FMODE_WRITE must correspond