Patched code sample

import os

def create_workflow(workflow_name, workflow_definition, base_path="/app/workflows"):
    """
    Creates a workflow directory and definition file.  Mitigates path traversal.

    Args:
        workflow_name (str): The name of the workflow.
        workflow_definition (str): The workflow definition (e.g., JSON).
        base_path (str):  The base directory for workflows.

    Returns:
        str: Path to the created workflow file, or None on error.
    """

    # Sanitize the workflow name to prevent path traversal
    safe_workflow_name = os.path.basename(workflow_name)  # Extract filename only
    if safe_workflow_name != workflow_name:
        print(f"Warning: Workflow name '{workflow_name}' contained potentially unsafe characters. Using '{safe_workflow_name}' instead.")


    workflow_dir = os.path.join(base_path, safe_workflow_name)


    # Prevent creating directory outside of base path
    normalized_path = os.path.normpath(workflow_dir)
    if not normalized_path.startswith(os.path.normpath(base_path)):
        print("Error: Attempted path traversal. Workflow creation blocked.")
        return None

    try:
        os.makedirs(workflow_dir, exist_ok=True)  # Create directory if it doesn't exist
        workflow_file_path = os.path.join(workflow_dir, "workflow.json")  # Fixed filename

        with open(workflow_file_path, "w") as f:
            f.write(workflow_definition)

        return workflow_file_path

    except OSError as e:
        print(f"Error creating workflow: {e}")
        return None