The steps to reproduce the problem:
1) Create a batch task.
2) Kick it off and put in the build queue.
3) Click the red cross icon to cancel.
4) Observe it redirects to 404 error page.

Please note that the link associated with the icon doesn't contain neither job name nor task name.
e.g. http://ci-test.tva.tvworks.com/hudson/cancelQueue

I set P2 because I can't find the way to cancel the task other than this way.

I confirmed the issue with build 1.218.