Before you get all angry and upset on the matter, you should know that there’s a good reason for this commit, and this is – security of course. It’s suppose to make your phone more secure by preventing apps / programs from executing malicious code on the /data partition.
A recent commit to the AOSP master tree prevents the unconfined domain (everything you run through su by default) from executing files located on the /data partition. …This will no longer work out-of-the-box, and generate an access denied error.
The good news though, are that app developers will be able to go around the issue, as long as they will be informed about it. So, now might be a good time for you to contact your favourite root-app developer and let him know about the issue.