LSM: Add security_path_chmod() and security_path_chown().

This patch allows pathname based LSM modules to check chmod()/chown()
operations. Since notify_change() does not receive "struct vfsmount *",
we add security_path_chmod() and security_path_chown() to the caller of
notify_change().

These hooks are used by TOMOYO.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 30 insertions, 0 deletions

diff --git a/include/linux/security.h b/include/linux/security.h
index 239e40d0450b..c8a584c26f7b 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -447,6 +447,18 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
  *      @new_dir contains the path structure for parent of the new link.
  *      @new_dentry contains the dentry structure of the new link.
  *      Return 0 if permission is granted.
+ * @path_chmod:
+ *      Check for permission to change DAC's permission of a file or directory.
+ *      @dentry contains the dentry structure.
+ *      @mnt contains the vfsmnt structure.
+ *      @mode contains DAC's mode.
+ *      Return 0 if permission is granted.
+ * @path_chown:
+ *      Check for permission to change owner/group of a file or directory.
+ *      @path contains the path structure.
+ *      @uid contains new owner's ID.
+ *      @gid contains new group's ID.
+ *      Return 0 if permission is granted.
  * @inode_readlink:
  *      Check the permission to read the symbolic link.
  *      @dentry contains the dentry structure for the file link.
@@ -1488,6 +1500,9 @@ struct security_operations {
                           struct dentry *new_dentry);
         int (*path_rename) (struct path *old_dir, struct dentry *old_dentry,
                             struct path *new_dir, struct dentry *new_dentry);
+        int (*path_chmod) (struct dentry *dentry, struct vfsmount *mnt,
+                           mode_t mode);
+        int (*path_chown) (struct path *path, uid_t uid, gid_t gid);
 #endif
 
         int (*inode_alloc_security) (struct inode *inode);
@@ -2952,6 +2967,9 @@ int security_path_link(struct dentry *old_dentry, struct path *new_dir,
                        struct dentry *new_dentry);
 int security_path_rename(struct path *old_dir, struct dentry *old_dentry,
                          struct path *new_dir, struct dentry *new_dentry);
+int security_path_chmod(struct dentry *dentry, struct vfsmount *mnt,
+                        mode_t mode);
+int security_path_chown(struct path *path, uid_t uid, gid_t gid);
 #else   /* CONFIG_SECURITY_PATH */
 static inline int security_path_unlink(struct path *dir, struct dentry *dentry)
 {
@@ -3001,6 +3019,18 @@ static inline int security_path_rename(struct path *old_dir,
 {
         return 0;
 }
+
+static inline int security_path_chmod(struct dentry *dentry,
+                                      struct vfsmount *mnt,
+                                      mode_t mode)
+{
+        return 0;
+}
+
+static inline int security_path_chown(struct path *path, uid_t uid, gid_t gid)
+{
+        return 0;
+}
 #endif  /* CONFIG_SECURITY_PATH */
 
 #ifdef CONFIG_KEYS