From: Andreas Gruenbacher <agruenba@redhat.com>
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: [RFC v7 03/41] vfs: Add MAY_DELETE_SELF and MAY_DELETE_CHILD permission flags
Date: Sat, 5 Sep 2015 12:26:58 +0200 [thread overview]
Message-ID: <1441448856-13478-4-git-send-email-agruenba@redhat.com> (raw)
In-Reply-To: <1441448856-13478-1-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 does not override the sticky directory
check. It probably should.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
---
fs/namei.c | 19 +++++++++++++------
include/linux/fs.h | 2 ++
2 files changed, 15 insertions(+), 6 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index 428b4a6..d7bd134 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;
@@ -2538,8 +2538,15 @@ 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 && IS_RICHACL(inode)) {
+ /* Deleting is also permitted with MAY_EXEC on the directory
+ * and MAY_DELETE_SELF on the inode. */
+ if (!inode_permission(inode, MAY_DELETE_SELF) &&
+ !inode_permission(dir, mask))
+ error = 0;
+ }
if (error)
return error;
if (IS_APPEND(dir))
diff --git a/include/linux/fs.h b/include/linux/fs.h
index e4d701c..8e130e1 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
--
2.4.3
next prev parent reply other threads:[~2015-09-05 10:29 UTC|newest]
Thread overview: 109+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-05 10:26 [RFC v7 00/41] Richacls Andreas Gruenbacher
2015-09-05 10:26 ` [RFC v7 01/41] vfs: Add IS_ACL() and IS_RICHACL() tests Andreas Gruenbacher
2015-09-05 10:26 ` [RFC v7 02/41] vfs: Add MAY_CREATE_FILE and MAY_CREATE_DIR permission flags Andreas Gruenbacher
2015-09-05 10:26 ` Andreas Gruenbacher [this message]
2015-09-06 8:14 ` [PATCH] vfs: Add MAY_DELETE_SELF and MAY_DELETE_CHILD " Andreas Gruenbacher
2015-09-11 20:30 ` J. Bruce Fields
2015-09-05 10:26 ` [RFC v7 04/41] vfs: Make the inode passed to inode_change_ok non-const Andreas Gruenbacher
2015-09-05 10:27 ` [RFC v7 05/41] vfs: Add permission flags for setting file attributes Andreas Gruenbacher
2015-09-05 10:27 ` [RFC v7 06/41] richacl: In-memory representation and helper functions Andreas Gruenbacher
2015-09-05 10:27 ` [RFC v7 07/41] richacl: Permission mapping functions Andreas Gruenbacher
2015-09-05 10:27 ` [RFC v7 08/41] richacl: Compute maximum file masks from an acl Andreas Gruenbacher
2015-09-05 10:27 ` [RFC v7 09/41] richacl: Update the file masks in chmod() Andreas Gruenbacher
2015-09-11 20:35 ` J. Bruce Fields
2015-09-05 10:27 ` [RFC v7 10/41] richacl: Permission check algorithm Andreas Gruenbacher
2015-09-11 21:16 ` J. Bruce Fields
2015-09-11 22:12 ` Andreas Grünbacher
2015-09-17 17:30 ` J. Bruce Fields
2015-09-05 10:27 ` [RFC v7 11/41] vfs: Cache base_acl objects in inodes Andreas Gruenbacher
2015-09-05 10:27 ` [RFC v7 12/41] vfs: Cache richacl in struct inode Andreas Gruenbacher
2015-09-05 10:27 ` [RFC v7 13/41] richacl: Check if an acl is equivalent to a file mode Andreas Gruenbacher
2015-09-17 18:22 ` J. Bruce Fields
2015-09-18 0:56 ` J. Bruce Fields
2015-09-21 13:59 ` Austin S Hemmelgarn
2015-09-21 14:38 ` J. Bruce Fields
2015-09-21 17:00 ` Austin S Hemmelgarn
2015-09-21 17:48 ` J. Bruce Fields
2015-09-21 15:31 ` J. Bruce Fields
2015-09-21 23:26 ` Andreas Gruenbacher
2015-09-21 23:20 ` Andreas Gruenbacher
2015-09-17 18:37 ` J. Bruce Fields
2015-09-05 10:27 ` [RFC v7 14/41] richacl: Create-time inheritance Andreas Gruenbacher
2015-09-18 17:58 ` J. Bruce Fields
2015-09-21 20:37 ` Andreas Gruenbacher
2015-09-05 10:27 ` [RFC v7 15/41] richacl: Automatic Inheritance Andreas Gruenbacher
2015-09-18 18:40 ` J. Bruce Fields
2015-09-21 21:19 ` Andreas Gruenbacher
2015-09-22 1:51 ` J. Bruce Fields
2015-09-23 13:55 ` J. Bruce Fields
2015-09-05 10:27 ` [RFC v7 16/41] richacl: xattr mapping functions Andreas Gruenbacher
2015-09-05 10:27 ` [RFC v7 17/41] vfs: Add richacl permission checking Andreas Gruenbacher
2015-09-05 10:27 ` [RFC v7 18/41] ext4: Add richacl support Andreas Gruenbacher
2015-09-23 2:30 ` Aneesh Kumar K.V
2015-09-05 10:27 ` [RFC v7 19/41] ext4: Add richacl feature flag Andreas Gruenbacher
2015-09-23 2:31 ` Aneesh Kumar K.V
2015-09-05 10:27 ` [RFC v7 20/41] richacl: acl editing helper functions Andreas Gruenbacher
2015-09-18 18:54 ` J. Bruce Fields
2015-09-05 10:27 ` [RFC v7 21/41] richacl: Move everyone@ aces down the acl Andreas Gruenbacher
2015-09-18 19:35 ` J. Bruce Fields
2015-09-21 21:43 ` Andreas Gruenbacher
2015-09-22 1:52 ` J. Bruce Fields
2015-09-05 10:27 ` [RFC v7 22/41] richacl: Propagate everyone@ permissions to other aces Andreas Gruenbacher
2015-09-18 21:36 ` J. Bruce Fields
2015-09-21 23:44 ` Andreas Gruenbacher
2015-09-18 21:56 ` J. Bruce Fields
2015-09-21 19:24 ` J. Bruce Fields
2015-09-23 1:24 ` Andreas Gruenbacher
2015-09-23 1:39 ` Andreas Gruenbacher
2015-09-23 1:46 ` J. Bruce Fields
2015-09-05 10:27 ` [RFC v7 23/41] richacl: Set the owner permissions to the owner mask Andreas Gruenbacher
2015-09-21 21:00 ` J. Bruce Fields
2015-09-05 10:27 ` [RFC v7 24/41] richacl: Set the other permissions to the other mask Andreas Gruenbacher
2015-09-23 14:03 ` J. Bruce Fields
2015-09-23 14:12 ` Andreas Grünbacher
2015-09-05 10:27 ` [RFC v7 25/41] richacl: Isolate the owner and group classes Andreas Gruenbacher
2015-09-22 16:06 ` J. Bruce Fields
2015-09-23 13:11 ` Andreas Gruenbacher
2015-09-23 13:15 ` J. Bruce Fields
2015-09-22 19:02 ` J. Bruce Fields
2015-09-23 13:33 ` Andreas Gruenbacher
2015-09-25 11:25 ` Andreas Gruenbacher
2015-09-25 20:17 ` J. Bruce Fields
2015-09-22 19:02 ` J. Bruce Fields
2015-09-05 10:27 ` [RFC v7 26/41] richacl: Apply the file masks to a richacl Andreas Gruenbacher
2015-09-22 19:11 ` J. Bruce Fields
2015-09-23 19:18 ` J. Bruce Fields
2015-09-23 20:29 ` Andreas Gruenbacher
2015-09-23 20:33 ` J. Bruce Fields
2015-09-23 20:40 ` Andreas Gruenbacher
2015-09-23 21:05 ` J. Bruce Fields
2015-09-23 22:14 ` Andreas Gruenbacher
2015-09-24 15:28 ` J. Bruce Fields
2015-09-24 15:48 ` Andreas Gruenbacher
2015-09-22 20:50 ` J. Bruce Fields
2015-09-24 18:33 ` J. Bruce Fields
2015-09-25 16:21 ` [PATCH] richacl: Possible other write-through fix Andreas Gruenbacher
2015-09-25 16:45 ` Andreas Gruenbacher
2015-09-25 18:36 ` J. Bruce Fields
2015-09-05 10:27 ` [RFC v7 27/41] richacl: Create richacl from mode values Andreas Gruenbacher
2015-09-23 20:11 ` J. Bruce Fields
2015-09-05 10:27 ` [RFC v7 28/41] nfsd: Keep list of acls to dispose of in compoundargs Andreas Gruenbacher
2015-09-23 20:28 ` J. Bruce Fields
2015-09-05 10:27 ` [RFC v7 29/41] nfsd: Use richacls as internal acl representation Andreas Gruenbacher
2015-09-24 19:29 ` J. Bruce Fields
2015-09-05 10:27 ` [RFC v7 30/41] nfsd: Add richacl support Andreas Gruenbacher
2015-09-24 19:38 ` J. Bruce Fields
2015-09-05 10:27 ` [RFC v7 31/41] nfsd: Add support for the v4.1 dacl attribute Andreas Gruenbacher
2015-09-24 19:59 ` J. Bruce Fields
2015-09-25 16:37 ` Andreas Gruenbacher
2015-09-05 10:27 ` [RFC v7 32/41] nfsd: Add support for the MAY_CREATE_{FILE,DIR} permissions Andreas Gruenbacher
2015-09-24 20:01 ` J. Bruce Fields
2015-09-05 10:27 ` [RFC v7 33/41] richacl: Add support for unmapped identifiers Andreas Gruenbacher
2015-09-05 10:27 ` [RFC v7 34/41] ext4: Don't allow unmapped identifiers in richacls Andreas Gruenbacher
2015-09-05 10:27 ` [RFC v7 35/41] sunrpc: Allow to demand-allocate pages to encode into Andreas Gruenbacher
2015-09-05 10:27 ` [RFC v7 36/41] sunrpc: Add xdr_init_encode_pages Andreas Gruenbacher
2015-09-05 10:27 ` [RFC v7 37/41] nfs: Fix GETATTR bitmap verification Andreas Gruenbacher
2015-09-05 10:27 ` [RFC v7 38/41] nfs: Remove unused xdr page offsets in getacl/setacl arguments Andreas Gruenbacher
2015-09-05 10:27 ` [RFC v7 39/41] nfs: Add richacl support Andreas Gruenbacher
2015-09-05 10:27 ` [RFC v7 40/41] nfs: Add support for the v4.1 dacl attribute Andreas Gruenbacher
2015-09-05 10:27 ` [RFC v7 41/41] richacl: uapi header split Andreas Gruenbacher
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