diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 45239ef63e8c..2018e3114655 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -82,13 +82,13 @@ static int ovl_casefold(struct ovl_readdir_data *rdd, const char *str, int len,
 	    name_is_dot_dotdot(str, len))
 		return 0;
 
-	cf_name = kmalloc(NAME_MAX, GFP_KERNEL);
+	cf_name = kmalloc(NAME_MAX + 1, GFP_KERNEL);
 	if (!cf_name) {
 		rdd->err = -ENOMEM;
 		return -ENOMEM;
 	}
 
-	cf_len = utf8_casefold(rdd->map, &qstr, cf_name, NAME_MAX);
+	cf_len = utf8_casefold(rdd->map, &qstr, cf_name, NAME_MAX + 1);
 	if (cf_len > 0)
 		*dst = cf_name;
 	else