diff --git a/examples/file/listdir.c b/examples/file/listdir.c
index 98419db873f9d411fed7487961d2f84d14869bb6..3300389ab9bb2ecd8c49335b64aa3a5ab37a5c5e 100644
--- a/examples/file/listdir.c
+++ b/examples/file/listdir.c
@@ -13,7 +13,7 @@
 
 void list_dir(const char* path)
 {
-    char * fullpath;
+    char * fullpath = RT_NULL;
 	DIR *dir;
 
 	dir = opendir(path);
@@ -26,6 +26,7 @@ void list_dir(const char* path)
 	    if (fullpath == RT_NULL)
 	    {
 	        rt_kprintf("no memory\n");
+            closedir(dir);
 	        return;
 	    }
 
@@ -55,8 +56,13 @@ void list_dir(const char* path)
 	{
 	    rt_kprintf("open %s directory failed\n", path);
 	}
-
-	rt_free(fullpath);
+    
+	if (RT_NULL != fullpath)
+    {
+        rt_free(fullpath);
+        fullpath = RT_NULL;
+	}
+	
 }
 
 #ifdef RT_USING_FINSH