diff --git a/interfaces/kits/js/src/mod_fs/class_watcher/watcher_entity.cpp b/interfaces/kits/js/src/mod_fs/class_watcher/watcher_entity.cpp
index ee0c1b56d2b99a521eb29d533e8bcaf03a246f1a..54d9851bf661c9108e871f98db268bb486d7410a 100644
--- a/interfaces/kits/js/src/mod_fs/class_watcher/watcher_entity.cpp
+++ b/interfaces/kits/js/src/mod_fs/class_watcher/watcher_entity.cpp
@@ -194,7 +194,7 @@ void FileWatcher::ReadNotifyEvent(WatcherCallback callback)
     while (((len = read(notifyFd_, &buf, sizeof(buf))) < 0) && (errno == EINTR)) {};
     while (index < len) {
         event = reinterpret_cast<inotify_event *>(buf + index);
-        if (sizeof(struct inotify_event) > (len - index)) {
+        if ((len - index) < sizeof(struct inotify_event)) {
             HILOGE("out of bounds access, len:%{public}d, index: %{public}d, inotify: %{public}zu",
                    len, index, sizeof(struct inotify_event));
             break;