diff --git a/fs/udf/unicode.c b/fs/udf/unicode.c
index 61a1738895b7..ad04dc227833 100644
--- a/fs/udf/unicode.c
+++ b/fs/udf/unicode.c
@@ -268,7 +268,7 @@ static int udf_name_from_CS0(uint8_t *str_o, int str_max_len,
 	}
 
 	if (translate) {
-		if (str_o_len <= 2 && str_o[0] == '.' &&
+		if (str_o_len > 0 && str_o_len <= 2 && str_o[0] == '.' &&
 		    (str_o_len == 1 || str_o[1] == '.'))
 			needsCRC = 1;
 		if (needsCRC) {