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>

2 files changed, 28 insertions, 0 deletions

diff --git a/security/capability.c b/security/capability.c
index fce07a7bc825..09279a8d4a14 100644
--- a/security/capability.c
+++ b/security/capability.c
@@ -308,6 +308,17 @@ static int cap_path_truncate(struct path *path, loff_t length,
 {
         return 0;
 }
+
+static int cap_path_chmod(struct dentry *dentry, struct vfsmount *mnt,
+                          mode_t mode)
+{
+        return 0;
+}
+
+static int cap_path_chown(struct path *path, uid_t uid, gid_t gid)
+{
+        return 0;
+}
 #endif
 
 static int cap_file_permission(struct file *file, int mask)
@@ -977,6 +988,8 @@ void security_fixup_ops(struct security_operations *ops)
         set_to_cap_if_null(ops, path_link);
         set_to_cap_if_null(ops, path_rename);
         set_to_cap_if_null(ops, path_truncate);
+        set_to_cap_if_null(ops, path_chmod);
+        set_to_cap_if_null(ops, path_chown);
 #endif
         set_to_cap_if_null(ops, file_permission);
         set_to_cap_if_null(ops, file_alloc_security);
diff --git a/security/security.c b/security/security.c
index c4c673240c1c..5259270e558f 100644
--- a/security/security.c
+++ b/security/security.c
@@ -434,6 +434,21 @@ int security_path_truncate(struct path *path, loff_t length,
                 return 0;
         return security_ops->path_truncate(path, length, time_attrs);
 }
+
+int security_path_chmod(struct dentry *dentry, struct vfsmount *mnt,
+                        mode_t mode)
+{
+        if (unlikely(IS_PRIVATE(dentry->d_inode)))
+                return 0;
+        return security_ops->path_chmod(dentry, mnt, mode);
+}
+
+int security_path_chown(struct path *path, uid_t uid, gid_t gid)
+{
+        if (unlikely(IS_PRIVATE(path->dentry->d_inode)))
+                return 0;
+        return security_ops->path_chown(path, uid, gid);
+}
 #endif
 
 int security_inode_create(struct inode *dir, struct dentry *dentry, int mode)