If you deleted the function outside of CloudFormation, then you can manually create a new function of the same name. This sometimes helps.

You can also wait till the rollback timeouts. And it usually does after a while, but the time varies.

Another reason why it gets stuck in this state could be due to nested stacks:

• Nested Stacks are Stuck in UPDATE_COMPLETE_CLEANUP_IN_PROGRESS, UPDATE_ROLLBACK_COMPLETE_CLEANUP_IN_PROGRESS, or UPDATE_ROLLBACK_IN_PROGRESS

In this case a recommended option is indeed to contact support:

To fix the stack, contact AWS customer support.

Recent AWS blog post also describes the issue and possible solutions:

• Why is my AWS CloudFormation stack stuck in the state CREATE_IN_PROGRESS, UPDATE_IN_PROGRESS, UPDATE_ROLLBACK_IN_PROGRESS, or DELETE_IN_PROGRESS?

Regarding the time to wait, the timeout varies:

In most situations, you must wait for your AWS CloudFormation stack to time out. The timeout length varies, and is based on the individual resource stabilization requirements that AWS CloudFormation waits for to reach the desired state.

In our case, we have mistakenly passed wrong image name to cloudformation template. After realising the mistake, we tried to stop the stack update, which made the stack stuck for forever in UPDATE_ROLLBACK_IN_PROGRESS status. SO during ECS service creation it got stuck. Solution:

1. in Stack event check in which step is in progress. (our case ECS service update)
2. Go to ECS service.
3. Click on Update service.
4. Choose older task definitions.
5. And Update.

Your Task definition is reset to previous version. And roll back will complete successfully.