[patch 5/8] vfs: annotate permission operations
From: Miklos Szeredi
Date: Thu May 29 2008 - 07:35:48 EST
From: Miklos Szeredi <mszeredi@xxxxxxx>
Add more PERM_OP_ flags to permission() calls. This allows
filesystems like NFS and security modules like AppArmor to make
precise decisions about whent permissions need to be checked, and when
they will be checked later together with the actual operation.
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxx>
---
fs/namei.c | 16 ++++++++--------
fs/nfsd/nfsfh.c | 2 +-
fs/open.c | 6 +++---
fs/utimes.c | 2 +-
fs/xattr.c | 2 +-
include/linux/fs.h | 19 +++++++++++++++++++
6 files changed, 33 insertions(+), 14 deletions(-)
Index: linux-2.6/fs/namei.c
===================================================================
--- linux-2.6.orig/fs/namei.c 2008-05-29 12:46:20.000000000 +0200
+++ linux-2.6/fs/namei.c 2008-05-29 12:46:24.000000000 +0200
@@ -492,7 +492,7 @@ static int exec_permission_lite(struct i
return -EACCES;
ok:
- return security_inode_permission(inode, MAY_EXEC);
+ return security_inode_permission(inode, MAY_LOOKUP);
}
/*
@@ -899,7 +899,7 @@ static int __link_path_walk(const char *
nd->flags |= LOOKUP_CONTINUE;
err = exec_permission_lite(inode);
if (err == -EAGAIN)
- err = path_permission(&nd->path, MAY_EXEC);
+ err = path_permission(&nd->path, MAY_LOOKUP);
if (err)
break;
@@ -1174,7 +1174,7 @@ static int do_path_lookup(int dfd, const
if (!S_ISDIR(dentry->d_inode->i_mode))
goto fput_fail;
- retval = file_permission(file, MAY_EXEC);
+ retval = file_permission(file, MAY_LOOKUP);
if (retval)
goto fput_fail;
@@ -1347,7 +1347,7 @@ static struct dentry *lookup_hash(struct
{
int err;
- err = path_permission(&nd->path, MAY_EXEC);
+ err = path_permission(&nd->path, MAY_LOOKUP);
if (err)
return ERR_PTR(err);
return __lookup_hash(&nd->last, nd->path.dentry, nd);
@@ -1395,7 +1395,7 @@ struct dentry *lookup_one_len(const char
if (err)
return ERR_PTR(err);
- err = dentry_permission(base, MAY_EXEC);
+ err = dentry_permission(base, MAY_LOOKUP);
if (err)
return ERR_PTR(err);
return __lookup_hash(&this, base, NULL);
@@ -1487,7 +1487,7 @@ static int may_delete(struct dentry *dir
BUG_ON(victim->d_parent->d_inode != dir);
audit_inode_child(victim->d_name.name, victim, dir);
- error = dentry_permission(dir_dentry, MAY_WRITE | MAY_EXEC);
+ error = dentry_permission(dir_dentry, MAY_DELETE);
if (error)
return error;
if (IS_APPEND(dir))
@@ -1523,7 +1523,7 @@ static inline int may_create(struct dent
return -EEXIST;
if (IS_DEADDIR(dir_dentry->d_inode))
return -ENOENT;
- return dentry_permission(dir_dentry, MAY_WRITE | MAY_EXEC);
+ return dentry_permission(dir_dentry, MAY_CREATE);
}
/*
@@ -2687,7 +2687,7 @@ static int vfs_rename_dir(struct inode *
* we'll need to flip '..'.
*/
if (new_dir != old_dir) {
- error = dentry_permission(old_dentry, MAY_WRITE);
+ error = dentry_permission(old_dentry, MAY_MOVE_DIR);
if (error)
return error;
}
Index: linux-2.6/fs/nfsd/nfsfh.c
===================================================================
--- linux-2.6.orig/fs/nfsd/nfsfh.c 2008-05-29 12:46:23.000000000 +0200
+++ linux-2.6/fs/nfsd/nfsfh.c 2008-05-29 12:46:24.000000000 +0200
@@ -52,7 +52,7 @@ static int nfsd_acceptable(void *expv, s
int err;
parent.dentry = dget_parent(tdentry);
- err = path_permission(&parent, MAY_EXEC);
+ err = path_permission(&parent, MAY_LOOKUP);
if (err < 0) {
dput(parent.dentry);
break;
Index: linux-2.6/fs/open.c
===================================================================
--- linux-2.6.orig/fs/open.c 2008-05-29 12:46:20.000000000 +0200
+++ linux-2.6/fs/open.c 2008-05-29 12:46:24.000000000 +0200
@@ -513,7 +513,7 @@ asmlinkage long sys_chdir(const char __u
if (error)
goto out;
- error = path_permission(&nd.path, MAY_EXEC | PERM_OP_CHDIR);
+ error = path_permission(&nd.path, MAY_CHDIR);
if (error)
goto dput_and_out;
@@ -542,7 +542,7 @@ asmlinkage long sys_fchdir(unsigned int
if (!S_ISDIR(inode->i_mode))
goto out_putf;
- error = file_permission(file, MAY_EXEC | PERM_OP_CHDIR);
+ error = file_permission(file, MAY_CHDIR);
if (!error)
set_fs_pwd(current->fs, &file->f_path);
out_putf:
@@ -560,7 +560,7 @@ asmlinkage long sys_chroot(const char __
if (error)
goto out;
- error = path_permission(&nd.path, MAY_EXEC);
+ error = path_permission(&nd.path, MAY_CHROOT);
if (error)
goto dput_and_out;
Index: linux-2.6/fs/utimes.c
===================================================================
--- linux-2.6.orig/fs/utimes.c 2008-05-29 12:46:20.000000000 +0200
+++ linux-2.6/fs/utimes.c 2008-05-29 12:46:24.000000000 +0200
@@ -141,7 +141,7 @@ static int do_utimes_name(int dfd, char
goto out_path_put;
if (!is_owner_or_cap(inode)) {
- error = path_permission(&nd.path, MAY_WRITE);
+ error = path_permission(&nd.path, MAY_UTIMES);
if (error)
goto out_path_put;
}
Index: linux-2.6/fs/xattr.c
===================================================================
--- linux-2.6.orig/fs/xattr.c 2008-05-29 12:46:20.000000000 +0200
+++ linux-2.6/fs/xattr.c 2008-05-29 12:46:24.000000000 +0200
@@ -65,7 +65,7 @@ xattr_permission(struct path *path, cons
return -EPERM;
}
- return path_permission(path, mask);
+ return path_permission(path, mask | PERM_OP_XATTR);
}
static int
Index: linux-2.6/include/linux/fs.h
===================================================================
--- linux-2.6.orig/include/linux/fs.h 2008-05-29 12:46:20.000000000 +0200
+++ linux-2.6/include/linux/fs.h 2008-05-29 12:46:24.000000000 +0200
@@ -70,6 +70,25 @@ extern int dir_notify_enable;
#define PERM_OP_OPEN (0x1 << 28)
#define PERM_OP_ACCESS (0x2 << 28)
#define PERM_OP_CHDIR (0x3 << 28)
+#define PERM_OP_CHROOT (0x4 << 28)
+#define PERM_OP_LOOKUP (0x5 << 28)
+#define PERM_OP_CREATE (0x6 << 28)
+#define PERM_OP_DELETE (0x7 << 28)
+#define PERM_OP_MOVE_DIR (0x8 << 28)
+#define PERM_OP_UTIMES (0x9 << 28)
+#define PERM_OP_XATTR (0xa << 28)
+
+/*
+ * Combined MAY_ flags
+ */
+#define MAY_CHDIR (PERM_OP_CHDIR | MAY_EXEC)
+#define MAY_CHROOT (PERM_OP_CHROOT | MAY_EXEC)
+#define MAY_LOOKUP (PERM_OP_LOOKUP | MAY_EXEC)
+#define MAY_CREATE (PERM_OP_CREATE | MAY_EXEC | MAY_WRITE)
+#define MAY_DELETE (PERM_OP_DELETE | MAY_EXEC | MAY_WRITE)
+#define MAY_MOVE_DIR (PERM_OP_MOVE_DIR | MAY_WRITE)
+#define MAY_UTIMES (PERM_OP_UTIMES | MAY_WRITE)
+
#define FMODE_READ 1
#define FMODE_WRITE 2
--
--
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