linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Andreas Gruenbacher <agruenba@redhat.com>
To: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Gruenbacher <agruenba@redhat.com>,
	Christoph Hellwig <hch@infradead.org>,
	"Theodore Ts'o" <tytso@mit.edu>,
	Andreas Dilger <adilger.kernel@dilger.ca>,
	"J. Bruce Fields" <bfields@fieldses.org>,
	Jeff Layton <jlayton@poochiereds.net>,
	Trond Myklebust <trond.myklebust@primarydata.com>,
	Anna Schumaker <anna.schumaker@netapp.com>,
	Dave Chinner <david@fromorbit.com>,
	linux-ext4@vger.kernel.org, xfs@oss.sgi.com,
	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 v23 03/22] vfs: Add MAY_DELETE_SELF and MAY_DELETE_CHILD permission flags
Date: Thu, 30 Jun 2016 15:46:54 +0200	[thread overview]
Message-ID: <1467294433-3222-4-git-send-email-agruenba@redhat.com> (raw)
In-Reply-To: <1467294433-3222-1-git-send-email-agruenba@redhat.com>

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 <agruenba@redhat.com>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
Reviewed-by: Steve French <steve.french@primarydata.com>
---
 fs/namei.c         | 20 ++++++++++++--------
 include/linux/fs.h |  2 ++
 2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index dc91858..663933e 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -454,9 +454,9 @@ 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)
 {
@@ -2778,14 +2778,18 @@ 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_WRITE | 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) == 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))
@@ -2803,7 +2807,7 @@ static int may_delete_or_replace(struct inode *dir, struct dentry *victim,
 
 static int may_delete(struct inode *dir, struct dentry *victim, bool isdir)
 {
-	return may_delete_or_replace(dir, victim, isdir, MAY_WRITE | MAY_EXEC);
+	return may_delete_or_replace(dir, victim, isdir, MAY_EXEC);
 }
 
 static int may_replace(struct inode *dir, struct dentry *victim, bool isdir)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index dd614ad..86bfa10 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
-- 
2.5.5

  parent reply	other threads:[~2016-06-30 13:50 UTC|newest]

Thread overview: 56+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-30 13:46 [PATCH v23 00/22] Richacls (Core and Ext4) Andreas Gruenbacher
2016-06-30 13:46 ` [PATCH v23 01/22] vfs: Add IS_ACL() and IS_RICHACL() tests Andreas Gruenbacher
2016-07-05 11:00   ` Jeff Layton
2016-06-30 13:46 ` [PATCH v23 02/22] vfs: Add MAY_CREATE_FILE and MAY_CREATE_DIR permission flags Andreas Gruenbacher
2016-07-05 11:02   ` Jeff Layton
2016-06-30 13:46 ` Andreas Gruenbacher [this message]
2016-07-05 11:07   ` [PATCH v23 03/22] vfs: Add MAY_DELETE_SELF and MAY_DELETE_CHILD " Jeff Layton
2016-06-30 13:46 ` [PATCH v23 04/22] vfs: Make the inode passed to inode_change_ok non-const Andreas Gruenbacher
2016-07-05 11:12   ` Jeff Layton
2016-06-30 13:46 ` [PATCH v23 05/22] vfs: Add permission flags for setting file attributes Andreas Gruenbacher
2016-07-05 11:18   ` Jeff Layton
2016-06-30 13:46 ` [PATCH v23 06/22] richacl: In-memory representation and helper functions Andreas Gruenbacher
2016-07-05 11:34   ` Jeff Layton
2016-07-11 10:11     ` Andreas Gruenbacher
2016-06-30 13:46 ` [PATCH v23 07/22] richacl: Permission mapping functions Andreas Gruenbacher
2016-07-05 13:39   ` Jeff Layton
2016-07-11 13:26     ` Andreas Gruenbacher
2016-06-30 13:46 ` [PATCH v23 08/22] richacl: Compute maximum file masks from an acl Andreas Gruenbacher
2016-07-05 14:22   ` Jeff Layton
2016-07-05 17:08     ` Frank Filz
2016-07-13 12:34       ` Andreas Gruenbacher
2016-07-13 19:38         ` Frank Filz
2016-06-30 13:47 ` [PATCH v23 09/22] richacl: Permission check algorithm Andreas Gruenbacher
2016-07-05 14:59   ` Jeff Layton
2016-07-11 13:28     ` Andreas Gruenbacher
2016-06-30 13:47 ` [PATCH v23 10/22] posix_acl: Improve xattr fixup code Andreas Gruenbacher
2016-07-05 15:38   ` Jeff Layton
2016-06-30 13:47 ` [PATCH v23 11/22] vfs: Cache base_acl objects in inodes Andreas Gruenbacher
2016-07-05 15:56   ` Jeff Layton
2016-06-30 13:47 ` [PATCH v23 12/22] vfs: Add get_richacl and set_richacl inode operations Andreas Gruenbacher
2016-07-06 18:31   ` Jeff Layton
2016-06-30 13:47 ` [PATCH v23 13/22] vfs: Cache richacl in struct inode Andreas Gruenbacher
2016-07-06 18:57   ` Jeff Layton
2016-07-14 20:02     ` Andreas Gruenbacher
2016-07-07 14:14   ` David Howells
2016-06-30 13:47 ` [PATCH v23 14/22] richacl: Update the file masks in chmod() Andreas Gruenbacher
2016-07-12 11:36   ` Jeff Layton
2016-06-30 13:47 ` [PATCH v23 15/22] richacl: Check if an acl is equivalent to a file mode Andreas Gruenbacher
2016-07-12 11:39   ` Jeff Layton
2016-06-30 13:47 ` [PATCH v23 16/22] richacl: Create-time inheritance Andreas Gruenbacher
2016-07-12 11:41   ` Jeff Layton
2016-06-30 13:47 ` [PATCH v23 17/22] richacl: Automatic Inheritance Andreas Gruenbacher
2016-07-12 11:56   ` Jeff Layton
2016-07-12 19:11     ` J. Bruce Fields
2016-07-12 20:28       ` Andreas Gruenbacher
2016-06-30 13:47 ` [PATCH v23 18/22] richacl: xattr mapping functions Andreas Gruenbacher
2016-07-12 12:02   ` Jeff Layton
2016-07-14 20:33     ` Andreas Gruenbacher
2016-06-30 13:47 ` [PATCH v23 19/22] richacl: Add richacl xattr handler Andreas Gruenbacher
2016-07-12 12:13   ` Jeff Layton
2016-06-30 13:47 ` [PATCH v23 20/22] vfs: Add richacl permission checking Andreas Gruenbacher
2016-07-12 12:13   ` Jeff Layton
2016-07-14 20:59     ` Andreas Gruenbacher
2016-06-30 13:47 ` [PATCH v23 21/22] ext4: Add richacl support Andreas Gruenbacher
2016-06-30 13:47 ` [PATCH v23 22/22] ext4: Add richacl feature flag Andreas Gruenbacher
2016-06-30 14:11 ` [PATCH v23 00/22] Richacls (Core and Ext4) Volker Lendecke

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1467294433-3222-4-git-send-email-agruenba@redhat.com \
    --to=agruenba@redhat.com \
    --cc=adilger.kernel@dilger.ca \
    --cc=anna.schumaker@netapp.com \
    --cc=bfields@fieldses.org \
    --cc=david@fromorbit.com \
    --cc=hch@infradead.org \
    --cc=jlayton@poochiereds.net \
    --cc=linux-api@vger.kernel.org \
    --cc=linux-cifs@vger.kernel.org \
    --cc=linux-ext4@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-nfs@vger.kernel.org \
    --cc=trond.myklebust@primarydata.com \
    --cc=tytso@mit.edu \
    --cc=viro@zeniv.linux.org.uk \
    --cc=xfs@oss.sgi.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).