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Groups > linux.kernel > #1233794
| From | Andreas Gruenbacher <agruenba@redhat.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH v8 02/41] vfs: Add MAY_CREATE_FILE and MAY_CREATE_DIR permission flags |
| Date | 2015-09-28 00:50 +0200 |
| Message-ID | <qdsVz-419-3@gated-at.bofh.it> (permalink) |
| References | <qdsiR-3hB-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
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 <agruenba@redhat.com>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
---
fs/namei.c | 43 +++++++++++++++++++++++++------------------
include/linux/fs.h | 2 ++
2 files changed, 27 insertions(+), 18 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index 48c2752..7c0f310 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -453,7 +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.
*
- * When checking for MAY_APPEND, MAY_WRITE must also be set in @mask.
+ * 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.
*/
int inode_permission(struct inode *inode, int mask)
{
@@ -2545,10 +2547,11 @@ 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 = d_backing_inode(victim);
- int error;
+ int error, mask = MAY_WRITE | MAY_EXEC;
if (d_is_negative(victim))
return -ENOENT;
@@ -2557,7 +2560,9 @@ 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))
@@ -2588,14 +2593,16 @@ 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);
}
/*
@@ -2645,7 +2652,7 @@ 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;
@@ -3490,7 +3497,7 @@ 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;
@@ -3582,7 +3589,7 @@ 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)
@@ -3663,7 +3670,7 @@ 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;
@@ -3785,7 +3792,7 @@ 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;
@@ -3919,7 +3926,7 @@ 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;
@@ -4002,7 +4009,7 @@ 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;
@@ -4190,19 +4197,19 @@ 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;
@@ -4465,7 +4472,7 @@ 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 4efa435..d6e2330 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -82,6 +82,8 @@ typedef void (dax_iodone_t)(struct buffer_head *bh_map, int uptodate);
#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
--
2.4.3
--
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[PATCH v8 00/41] Richacls Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:10 +0200
[PATCH v8 31/41] nfsd: Add support for the v4.1 dacl attribute Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 15/41] richacl: Automatic Inheritance Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 03/41] vfs: Add MAY_DELETE_SELF and MAY_DELETE_CHILD permission flags Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 12/41] vfs: Cache richacl in struct inode Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 14/41] richacl: Create-time inheritance Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 33/41] richacl: Add support for unmapped identifiers Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 06/41] richacl: In-memory representation and helper functions Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 09/41] richacl: Update the file masks in chmod() Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
Re: [PATCH v8 09/41] richacl: Update the file masks in chmod() "J. Bruce Fields" <bfields@fieldses.org> - 2015-09-28 17:30 +0200
Re: [PATCH v8 09/41] richacl: Update the file masks in chmod() Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-29 01:50 +0200
[PATCH v8 13/41] richacl: Check if an acl is equivalent to a file mode Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 27/41] richacl: Create richacl from mode values Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 19/41] ext4: Add richacl feature flag Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 21/41] richacl: Move everyone@ aces down the acl Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 20/41] richacl: acl editing helper functions Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 32/41] nfsd: Add support for the MAY_CREATE_{FILE,DIR} permissions Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 26/41] richacl: Apply the file masks to a richacl Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 01/41] vfs: Add IS_ACL() and IS_RICHACL() tests Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 41/41] richacl: uapi header split Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 18/41] ext4: Add richacl support Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 17/41] vfs: Add richacl permission checking Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 35/41] sunrpc: Allow to demand-allocate pages to encode into Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 38/41] nfs: Remove unused xdr page offsets in getacl/setacl arguments Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 36/41] sunrpc: Add xdr_init_encode_pages Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 16/41] richacl: xattr mapping functions Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 25/41] richacl: Isolate the owner and group classes Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 40/41] nfs: Add support for the v4.1 dacl attribute Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 11/41] vfs: Cache base_acl objects in inodes Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 08/41] richacl: Compute maximum file masks from an acl Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 34/41] ext4: Don't allow unmapped identifiers in richacls Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 05/41] vfs: Add permission flags for setting file attributes Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 28/41] nfsd: Keep list of acls to dispose of in compoundargs Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 04/41] vfs: Make the inode passed to inode_change_ok non-const Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 22/41] richacl: Propagate everyone@ permissions to other aces Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 37/41] nfs: Fix GETATTR bitmap verification Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 29/41] nfsd: Use richacls as internal acl representation Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 39/41] nfs: Add richacl support Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 24/41] richacl: Set the other permissions to the other mask Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:30 +0200
[PATCH v8 23/41] richacl: Set the owner permissions to the owner mask Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:30 +0200
[PATCH v8 30/41] nfsd: Add richacl support Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:30 +0200
[PATCH v8 07/41] richacl: Permission mapping functions Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:40 +0200
[PATCH v8 10/41] richacl: Permission check algorithm Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:40 +0200
Re: [PATCH v8 10/41] richacl: Permission check algorithm "J. Bruce Fields" <bfields@fieldses.org> - 2015-09-28 18:10 +0200
Re: [PATCH v8 10/41] richacl: Permission check algorithm Andreas Grünbacher <andreas.gruenbacher@gmail.com> - 2015-09-28 18:30 +0200
Re: [PATCH v8 10/41] richacl: Permission check algorithm "J. Bruce Fields" <bfields@fieldses.org> - 2015-09-28 18:30 +0200
Re: [PATCH v8 10/41] richacl: Permission check algorithm Andreas Grünbacher <andreas.gruenbacher@gmail.com> - 2015-09-28 19:00 +0200
[PATCH v8 02/41] vfs: Add MAY_CREATE_FILE and MAY_CREATE_DIR permission flags Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:50 +0200
Re: [PATCH v8 00/41] Richacls "J. Bruce Fields" <bfields@fieldses.org> - 2015-09-28 18:40 +0200
Re: [PATCH v8 00/41] Richacls Andreas Grünbacher <andreas.gruenbacher@gmail.com> - 2015-09-28 19:20 +0200
Re: [PATCH v8 00/41] Richacls "J. Bruce Fields" <bfields@fieldses.org> - 2015-09-28 19:50 +0200
Re: [PATCH v8 00/41] Richacls Andreas Grünbacher <andreas.gruenbacher@gmail.com> - 2015-09-29 17:00 +0200
Re: [PATCH v8 00/41] Richacls Christoph Hellwig <hch@infradead.org> - 2015-10-04 08:30 +0200
Re: [PATCH v8 00/41] Richacls Andreas Gruenbacher <agruenba@redhat.com> - 2015-10-05 20:50 +0200
Re: [PATCH v8 00/41] Richacls Austin S Hemmelgarn <ahferroin7@gmail.com> - 2015-10-05 21:00 +0200
Re: [PATCH v8 00/41] Richacls Dave Chinner <david@fromorbit.com> - 2015-10-05 23:20 +0200
Re: [PATCH v8 00/41] Richacls Andreas Gruenbacher <agruenba@redhat.com> - 2015-10-06 00:10 +0200
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