fix: validate stack name to prevent crash with special characters

Author: Kiro

samcli/commands/deploy/deploy_context.py

@@ -17,6 +17,7 @@
 
 import logging
 import os
+import re
 from typing import Dict, List, Optional
 
 import boto3
@@ -120,6 +121,9 @@ def run(self):
         Execute deployment based on the argument provided by customers and samconfig.toml.
         """
 
+        if not re.match(r"^[a-zA-Z][-a-zA-Z0-9]*$", self.stack_name) or len(self.stack_name) > 128:
+            raise deploy_exceptions.DeployInvalidStackNameError(stack_name=self.stack_name)
+
         # Parse parameters
         with open(self.template_file, "r") as handle:
             template_str = handle.read()

samcli/commands/deploy/exceptions.py

@@ -43,6 +43,16 @@ def parse_findmap_error(error_message: str) -> Optional[Tuple[str, str]]:
     return None
 
 
+class DeployInvalidStackNameError(UserException):
+    def __init__(self, stack_name):
+        self.stack_name = stack_name
+        message_fmt = (
+            "Invalid stack name '{stack_name}'. Stack names must start with a letter, "
+            "contain only letters, numbers, and hyphens, and be at most 128 characters."
+        )
+        super().__init__(message=message_fmt.format(stack_name=self.stack_name))
+
+
 class ChangeEmptyError(UserException):
     def __init__(self, stack_name):
         self.stack_name = stack_name

tests/unit/commands/deploy/test_deploy_context.py

@@ -6,7 +6,7 @@
 
 from samcli.lib.deploy.deployer import Deployer
 from samcli.commands.deploy.deploy_context import DeployContext
-from samcli.commands.deploy.exceptions import DeployBucketRequiredError, DeployFailedError, ChangeEmptyError
+from samcli.commands.deploy.exceptions import DeployBucketRequiredError, DeployFailedError, ChangeEmptyError, DeployInvalidStackNameError
 from samcli.lib.deploy.utils import FailureMode
 from samcli.commands.deploy.exceptions import DeployFailedError
 
@@ -41,6 +41,21 @@ def setUp(self):
             max_wait_duration=60,
         )
 
+    def test_invalid_stack_name_special_chars(self):
+        self.deploy_command_context.stack_name = "my-stack@v2"
+        with self.assertRaises(DeployInvalidStackNameError):
+            self.deploy_command_context.run()
+
+    def test_invalid_stack_name_starts_with_digit(self):
+        self.deploy_command_context.stack_name = "1stack"
+        with self.assertRaises(DeployInvalidStackNameError):
+            self.deploy_command_context.run()
+
+    def test_invalid_stack_name_too_long(self):
+        self.deploy_command_context.stack_name = "a" * 129
+        with self.assertRaises(DeployInvalidStackNameError):
+            self.deploy_command_context.run()
+
     @patch("boto3.client")
     @patch("boto3.Session")
     def test_template_improper(self, mock_session, mock_boto):