MLS-C01 Modeling Practice Question

Exhibit

Refer to the exhibit.

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "sagemaker:CreateTrainingJob",
        "sagemaker:CreateModel",
        "sagemaker:CreateEndpointConfig",
        "sagemaker:CreateEndpoint"
      ],
      "Resource": "*"
    },
    {
      "Effect": "Allow",
      "Action": "s3:GetObject",
      "Resource": "arn:aws:s3:::my-bucket/training-data/*"
    }
  ]
}

A data scientist has this IAM policy attached to an IAM role used by SageMaker. When trying to create a training job, the scientist gets an access denied error. The training data is in 's3://my-bucket/training-data/'. What is the most likely cause?

⚠ Common exam trap

The MLS-C01 exam often tests the misconception that only s3:GetObject is needed to read objects from S3, but SageMaker's training job creation also requires s3:ListBucket to validate the bucket, making the missing ListBucket permission a common trap.

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

✓

Missing s3:ListBucket permission

The error occurs because the IAM policy grants s3:GetObject permission on the training data objects but lacks s3:ListBucket permission on the bucket itself. SageMaker's CreateTrainingJob API first performs a ListBucket call to verify the bucket exists and to enumerate objects, even if the exact object key is known. Without s3:ListBucket, the ListBucket call fails, resulting in an access denied error.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✗
The bucket name is misspelled
Why it's wrong here
The bucket name matches.
✗
The S3 resource ARN is incorrect
Why it's wrong here
The ARN matches the bucket and prefix.
✓
Missing s3:ListBucket permission
Why this is correct
SageMaker needs ListBucket permission to access objects.
✗
The sagemaker:CreateTrainingJob action is not allowed
Why it's wrong here
It is allowed with Resource '*'.

Quick reference

AWS S3 Storage Class Comparison

Storage Class	Min Duration	Retrieval	Use Case
S3 Standard	None	Immediate	Frequently accessed data
S3 Standard-IA	30 days	Immediate	Infrequent access, rapid retrieval
S3 One Zone-IA	30 days	Immediate	Non-critical infrequent data
S3 Intelligent-Tiering	None	Immediate–hours	Unknown or changing access patterns
S3 Glacier Instant	90 days	Milliseconds	Archive with instant retrieval
S3 Glacier Flexible	90 days	Minutes–hours	Archive, flexible retrieval
S3 Glacier Deep Archive	180 days	Hours	Long-term compliance archive

Go deeper

MLS-C01 Modeling Practice Question

Exhibit

Why each option matters

Option-by-option breakdown

AWS S3 Storage Class Comparison

Related to this question