IAM Policy to grant access to just one S3 bucket

iam-s3-policy.json

{
  "Statement": [
    {
      "Action": "s3:*",
      "Effect": "Allow",
      "Resource": [
        "arn:aws:s3:::mybucket",    
        "arn:aws:s3:::mybucket/*"
      ]
    }
  ]
}