diff --git a/fs/udf/unicode.c b/fs/udf/unicode.c
index ae6e809fa3aa..32c7f3d27f74 100644
--- a/fs/udf/unicode.c
+++ b/fs/udf/unicode.c
@@ -243,7 +243,7 @@ static int udf_name_from_CS0(struct super_block *sb,
 	}
 
 	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) {