Ensure FMODE_NONOTIFY is not set by userspace

[Lino Sanfilippo]

    In fsnotify_open() ensure that FMODE_NONOTIFY is never set by userspace.
    Also always call fsnotify_parent and fsnotify.

Signed-off-by: Lino Sanfilippo <LinoSanfilippo@xxxxxx>
---
This patch applies against commit 3970d817558a426cc2f53eaa01182eb9452e0cb1
of branch 'origin/for-next' from git.infradead.org/users/eparis/notify.git


diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h
index ecb43b3..5c185fa 100644
--- a/include/linux/fsnotify.h
+++ b/include/linux/fsnotify.h
@@ -235,10 +235,11 @@ static inline void fsnotify_open(struct file *file)
 	if (S_ISDIR(inode->i_mode))
 		mask |= FS_ISDIR;
 
-	if (!(file->f_mode & FMODE_NONOTIFY)) {
-		fsnotify_parent(path, NULL, mask);
-		fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
-	}
+	/* FMODE_NONOTIFY must never be set from user */
+	file->f_mode &= ~FMODE_NONOTIFY;
+
+	fsnotify_parent(path, NULL, mask);
+	fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
 }
 
 /*
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/