Pass Role And Get Role

To pass a role to a service, you need iam:PassRole. To get a role, you need iam:GetRole

Note: PassRole determines who should have the privilege to pass role to a service. Whereas AssumeRole is for the service to assume a role.

For example, this IAM Policy allows to pass S3Access to the ec2 instances.

Can any services assume role?

No, see Trust Policy