1 files changed, 15 insertions, 3 deletions

diff --git a/kernel/fs/notify/inotify/inotify_user.c b/kernel/fs/notify/inotify/inotify_user.c
index 450648697..b8d08d0d0 100644
--- a/kernel/fs/notify/inotify/inotify_user.c
+++ b/kernel/fs/notify/inotify/inotify_user.c
@@ -26,7 +26,7 @@
 #include <linux/fs.h> /* struct inode */
 #include <linux/fsnotify_backend.h>
 #include <linux/idr.h>
-#include <linux/init.h> /* module_init */
+#include <linux/init.h> /* fs_initcall */
 #include <linux/inotify.h>
 #include <linux/kernel.h> /* roundup() */
 #include <linux/namei.h> /* LOOKUP_FOLLOW */
@@ -706,7 +706,19 @@ SYSCALL_DEFINE3(inotify_add_watch, int, fd, const char __user *, pathname,
 	int ret;
 	unsigned flags = 0;
 
-	/* don't allow invalid bits: we don't want flags set */
+	/*
+	 * We share a lot of code with fs/dnotify.  We also share
+	 * the bit layout between inotify's IN_* and the fsnotify
+	 * FS_*.  This check ensures that only the inotify IN_*
+	 * bits get passed in and set in watches/events.
+	 */
+	if (unlikely(mask & ~ALL_INOTIFY_BITS))
+		return -EINVAL;
+	/*
+	 * Require at least one valid bit set in the mask.
+	 * Without _something_ set, we would have no events to
+	 * watch for.
+	 */
 	if (unlikely(!(mask & ALL_INOTIFY_BITS)))
 		return -EINVAL;
 
@@ -812,4 +824,4 @@ static int __init inotify_user_setup(void)
 
 	return 0;
 }
-module_init(inotify_user_setup);
+fs_initcall(inotify_user_setup);