Fix local connection and become issues (#84700)

* Fixed various become-related issues in `local` connection plugin.
* Fixed various issues in `sudo` and `su` become plugins.
* Added unit and integration test coverage.

Co-authored-by: Matt Clay <matt@mystile.com>
Co-authored-by: Matt Davis <nitzmahone@redhat.com>

changelogs/fragments/local-become-fixes.yml

@@ -0,0 +1,22 @@
+minor_changes:
+  - local connection plugin - A new ``become_success_timeout`` operation-wide timeout config (default 10s) was added for ``become``.
+  - local connection plugin - A new ``become_strip_preamble`` config option (default True) was added; disable to preserve diagnostic ``become`` output in task results.
+  - local connection plugin - When a ``become`` plugin's ``prompt`` value is a non-string after the ``check_password_prompt`` callback has completed, no prompt stripping will occur on stderr.
+
+bugfixes:
+  - local connection plugin - Fixed silent ignore of ``become`` failures and loss of task output when data arrived concurrently on stdout and stderr during ``become`` operation validation.
+  - local connection plugin - Fixed hang or spurious failure when data arrived concurrently on stdout and stderr during a successful ``become`` operation validation.
+  - local connection plugin - Fixed task output header truncation when post-become data arrived before ``become`` operation validation had completed.
+  - local connection plugin - Ensure ``become`` success validation always occurs, even when an active plugin does not set ``prompt``.
+  - local connection plugin - Fixed cases where the internal ``BECOME-SUCCESS`` message appeared in task output.
+  - local connection plugin - Fixed long timeout/hang for ``become`` plugins that repeat their prompt on failure (e.g., ``sudo``, some ``su`` implementations).
+  - local connection plugin - Fixed hang when an active become plugin incorrectly signals lack of prompt.
+  - local connection plugin - Fixed hang when a become plugin expects a prompt but a password was not provided.
+  - local connection plugin - Fixed hang when an internal become read timeout expired before the password prompt was written.
+  - local connection plugin - Fixed hang when only one of stdout or stderr was closed by the ``become_exe`` subprocess.
+  - local connection plugin - Become timeout errors now include all received data. Previously, the most recently-received data was discarded.
+  - sudo become plugin - The `sudo_chdir` config option allows the current directory to be set to the specified value before executing sudo to avoid permission errors when dropping privileges.
+  - su become plugin - Ensure generated regex from ``prompt_l10n`` config values is properly escaped.
+  - su become plugin - Ensure that password prompts are correctly detected in the presence of leading output. Previously, this case resulted in a timeout or hang.
+  - su become plugin - Ensure that trailing colon is expected on all ``prompt_l10n`` config values.
+  - ansible-test - Managed macOS instances now use the ``sudo_chdir`` option for the ``sudo`` become plugin to avoid permission errors when dropping privileges.

lib/ansible/plugins/become/__init__.py

@@ -3,6 +3,7 @@
 # GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
 from __future__ import annotations
 
+import re
 import shlex
 
 from abc import abstractmethod
@@ -13,6 +14,7 @@ from gettext import dgettext
 from ansible.errors import AnsibleError
 from ansible.module_utils.common.text.converters import to_bytes
 from ansible.plugins import AnsiblePlugin
+from ansible.utils import display as _display
 
 
 def _gen_id(length=32):
@@ -53,11 +55,11 @@ class BecomeBase(AnsiblePlugin):
 
             return getattr(playcontext, option, None)
 
-    def expect_prompt(self):
+    def expect_prompt(self) -> bool:
         """This function assists connection plugins in determining if they need to wait for
         a prompt. Both a prompt and a password are required.
         """
-        return self.prompt and self.get_option('become_pass')
+        return bool(self.prompt and self.get_option('become_pass'))
 
     def _build_success_command(self, cmd, shell, noexe=False):
         if not all((cmd, shell, self.success)):
@@ -65,9 +67,8 @@ class BecomeBase(AnsiblePlugin):
 
         try:
             cmd = shlex.quote('%s %s %s %s' % (shell.ECHO, self.success, shell.COMMAND_SEP, cmd))
-        except AttributeError:
-            # TODO: This should probably become some more robust functionality used to detect incompat
-            raise AnsibleError('The %s shell family is incompatible with the %s become plugin' % (shell.SHELL_FAMILY, self.name))
+        except AttributeError as ex:
+            raise AnsibleError(f'The {shell._load_name!r} shell plugin does not support become. It is missing the {ex.name!r} attribute.')
         exe = getattr(shell, 'executable', None)
         if exe and not noexe:
             cmd = '%s -c %s' % (exe, cmd)
@@ -78,6 +79,25 @@ class BecomeBase(AnsiblePlugin):
         self._id = _gen_id()
         self.success = 'BECOME-SUCCESS-%s' % self._id
 
+    def strip_become_prompt(self, data: bytes) -> bytes:
+        """
+        Strips the first found configured become prompt from `data`, trailing whitespace and anything that precedes the prompt, then returns the result.
+        If no prompt is expected, or the prompt is not `str` or `bytes`, `data` will be returned as-is.
+        """
+        if not self.prompt or not isinstance(self.prompt, (str, bytes)) or not self.expect_prompt():
+            return data
+
+        return self._strip_through_prefix(self.prompt, data)
+
+    def strip_become_success(self, data: bytes) -> bytes:
+        """Strips the first found success marker from `data`, trailing whitespace and anything that precedes the success marker, then returns the result."""
+        return self._strip_through_prefix(self.success, data)
+
+    @staticmethod
+    def _strip_through_prefix(match: str | bytes, data: bytes) -> bytes:
+        """Strips the first occurrence of `match` from `data`, trailing whitespace and anything that precedes `match`, then returns the result."""
+        return re.sub(br'^.*?' + re.escape(to_bytes(match)) + br'\s*', b'', data, count=1, flags=re.DOTALL)
+
     def check_success(self, b_output):
         b_success = to_bytes(self.success)
         return any(b_success in l.rstrip() for l in b_output.splitlines(True))

lib/ansible/plugins/become/su.py

@@ -93,7 +93,7 @@ DOCUMENTATION = """
 import re
 import shlex
 
-from ansible.module_utils.common.text.converters import to_bytes
+from ansible.module_utils.common.text.converters import to_text
 from ansible.plugins.become import BecomeBase
 
 
@@ -139,15 +139,18 @@ class BecomeModule(BecomeBase):
         '口令',
     ]
 
-    def check_password_prompt(self, b_output):
+    def check_password_prompt(self, b_output: bytes) -> bool:
         """ checks if the expected password prompt exists in b_output """
-
         prompts = self.get_option('prompt_l10n') or self.SU_PROMPT_LOCALIZATIONS
-        b_password_string = b"|".join((br'(\w+\'s )?' + to_bytes(p)) for p in prompts)
+        password_prompt_strings = "|".join(re.escape(p) for p in prompts)
         # Colon or unicode fullwidth colon
-        b_password_string = b_password_string + to_bytes(u' ?(:|：) ?')
-        b_su_prompt_localizations_re = re.compile(b_password_string, flags=re.IGNORECASE)
-        return bool(b_su_prompt_localizations_re.match(b_output))
+        prompt_pattern = rf"(?:{password_prompt_strings})\s*[:：]"
+        match = re.search(prompt_pattern, to_text(b_output), flags=re.IGNORECASE)
+
+        if match:
+            self.prompt = match.group(0)  # preserve the actual matched string so we can scrub the output
+
+        return bool(match)
 
     def build_become_command(self, cmd, shell):
         super(BecomeModule, self).build_become_command(cmd, shell)

lib/ansible/plugins/become/sudo.py

@@ -72,12 +72,25 @@ DOCUMENTATION = """
             ini:
               - section: sudo_become_plugin
                 key: password
+        sudo_chdir:
+            description: Directory to change to before invoking sudo; can avoid permission errors when dropping privileges.
+            type: string
+            required: False
+            version_added: '2.19'
+            vars:
+              - name: ansible_sudo_chdir
+            env:
+              - name: ANSIBLE_SUDO_CHDIR
+            ini:
+              - section: sudo_become_plugin
+                key: chdir
 """
 
 import re
 import shlex
 
 from ansible.plugins.become import BecomeBase
+from ansible.errors import AnsibleError
 
 
 class BecomeModule(BecomeBase):
@@ -117,4 +130,10 @@ class BecomeModule(BecomeBase):
         if user:
             user = '-u %s' % (user)
 
+        if chdir := self.get_option('sudo_chdir'):
+            try:
+                becomecmd = f'{shell.CD} {shlex.quote(chdir)} {shell._SHELL_AND} {becomecmd}'
+            except AttributeError as ex:
+                raise AnsibleError(f'The {shell._load_name!r} shell plugin does not support sudo chdir. It is missing the {ex.name!r} attribute.')
+
         return ' '.join([becomecmd, flags, prompt, user, self._build_success_command(cmd, shell)])

lib/ansible/plugins/connection/local.py

@@ -11,19 +11,38 @@ DOCUMENTATION = """
         - This connection plugin allows ansible to execute tasks on the Ansible 'controller' instead of on a remote host.
     author: ansible (@core)
     version_added: historical
+    options:
+        become_success_timeout:
+            version_added: '2.19'
+            type: int
+            default: 10
+            description:
+                - Number of seconds to wait for become to succeed when enabled.
+                - The default will be used if the configured value is less than 1.
+            vars:
+                - name: ansible_local_become_success_timeout
+        become_strip_preamble:
+            version_added: '2.19'
+            type: bool
+            default: true
+            description:
+                - Strip internal become output preceding command execution. Disable for additional diagnostics.
+            vars:
+                - name: ansible_local_become_strip_preamble
     extends_documentation_fragment:
         - connection_pipelining
     notes:
         - The remote user is ignored, the user with which the ansible CLI was executed is used instead.
 """
 
-import fcntl
+import functools
 import getpass
 import os
 import pty
 import selectors
 import shutil
 import subprocess
+import time
 import typing as t
 
 import ansible.constants as C
@@ -86,7 +105,7 @@ class Connection(ConnectionBase):
         else:
             cmd = map(to_bytes, cmd)
 
-        master = None
+        pty_primary = None
         stdin = subprocess.PIPE
         if sudoable and self.become and self.become.expect_prompt() and not self.get_option('pipelining'):
             # Create a pty if sudoable for privilege escalation that needs it.
@@ -94,7 +113,7 @@ class Connection(ConnectionBase):
             # cause the command to fail in certain situations where we are escalating
             # privileges or the command otherwise needs a pty.
             try:
-                master, stdin = pty.openpty()
+                pty_primary, stdin = pty.openpty()
             except (IOError, OSError) as e:
                 display.debug("Unable to open pty: %s" % to_native(e))
 
@@ -108,60 +127,134 @@ class Connection(ConnectionBase):
             stderr=subprocess.PIPE,
         )
 
-        # if we created a master, we can close the other half of the pty now, otherwise master is stdin
-        if master is not None:
+        # if we created a pty, we can close the other half of the pty now, otherwise primary is stdin
+        if pty_primary is not None:
             os.close(stdin)
 
         display.debug("done running command with Popen()")
 
-        if self.become and self.become.expect_prompt() and sudoable:
-            fcntl.fcntl(p.stdout, fcntl.F_SETFL, fcntl.fcntl(p.stdout, fcntl.F_GETFL) | os.O_NONBLOCK)
-            fcntl.fcntl(p.stderr, fcntl.F_SETFL, fcntl.fcntl(p.stderr, fcntl.F_GETFL) | os.O_NONBLOCK)
-            selector = selectors.DefaultSelector()
-            selector.register(p.stdout, selectors.EVENT_READ)
-            selector.register(p.stderr, selectors.EVENT_READ)
-
-            become_output = b''
-            try:
-                while not self.become.check_success(become_output) and not self.become.check_password_prompt(become_output):
-                    events = selector.select(self._play_context.timeout)
-                    if not events:
-                        stdout, stderr = p.communicate()
-                        raise AnsibleError('timeout waiting for privilege escalation password prompt:\n' + to_native(become_output))
-
-                    for key, event in events:
-                        if key.fileobj == p.stdout:
-                            chunk = p.stdout.read()
-                        elif key.fileobj == p.stderr:
-                            chunk = p.stderr.read()
-
-                    if not chunk:
-                        stdout, stderr = p.communicate()
-                        raise AnsibleError('privilege output closed while waiting for password prompt:\n' + to_native(become_output))
-                    become_output += chunk
-            finally:
-                selector.close()
-
-            if not self.become.check_success(become_output):
-                become_pass = self.become.get_option('become_pass', playcontext=self._play_context)
-                if master is None:
-                    p.stdin.write(to_bytes(become_pass, errors='surrogate_or_strict') + b'\n')
-                else:
-                    os.write(master, to_bytes(become_pass, errors='surrogate_or_strict') + b'\n')
-
-            fcntl.fcntl(p.stdout, fcntl.F_SETFL, fcntl.fcntl(p.stdout, fcntl.F_GETFL) & ~os.O_NONBLOCK)
-            fcntl.fcntl(p.stderr, fcntl.F_SETFL, fcntl.fcntl(p.stderr, fcntl.F_GETFL) & ~os.O_NONBLOCK)
+        become_stdout_bytes, become_stderr_bytes = self._ensure_become_success(p, pty_primary, sudoable)
 
         display.debug("getting output with communicate()")
         stdout, stderr = p.communicate(in_data)
         display.debug("done communicating")
 
+        # preserve output from privilege escalation stage as `bytes`; it may contain actual output (eg `raw`) or error messages
+        stdout = become_stdout_bytes + stdout
+        stderr = become_stderr_bytes + stderr
+
         # finally, close the other half of the pty, if it was created
-        if master:
-            os.close(master)
+        if pty_primary:
+            os.close(pty_primary)
 
         display.debug("done with local.exec_command()")
-        return (p.returncode, stdout, stderr)
+        return p.returncode, stdout, stderr
+
+    def _ensure_become_success(self, p: subprocess.Popen, pty_primary: int, sudoable: bool) -> tuple[bytes, bytes]:
+        """
+        Ensure that become succeeds, returning a tuple containing stdout captured after success and all stderr.
+        Returns immediately if `self.become` or `sudoable` are False, or `build_become_command` was not called, without performing any additional checks.
+        """
+        if not self.become or not sudoable or not self.become._id:  # _id is set by build_become_command, if it was not called, assume no become
+            return b'', b''
+
+        start_seconds = time.monotonic()
+        become_stdout = bytearray()
+        become_stderr = bytearray()
+        last_stdout_prompt_offset = 0
+        last_stderr_prompt_offset = 0
+
+        # map the buffers to their associated stream for the selector reads
+        become_capture = {
+            p.stdout: become_stdout,
+            p.stderr: become_stderr,
+        }
+
+        expect_password_prompt = self.become.expect_prompt()
+        sent_password = False
+
+        def become_error(reason: str) -> t.NoReturn:
+            error_message = f'{reason} waiting for become success'
+
+            if expect_password_prompt and not sent_password:
+                error_message += ' or become password prompt'
+
+            error_message += '.'
+
+            if become_stdout:
+                error_message += f'\n>>> Standard Output\n{to_text(bytes(become_stdout))}'
+
+            if become_stderr:
+                error_message += f'\n>>> Standard Error\n{to_text(bytes(become_stderr))}'
+
+            raise AnsibleError(error_message)
+
+        os.set_blocking(p.stdout.fileno(), False)
+        os.set_blocking(p.stderr.fileno(), False)
+
+        with selectors.DefaultSelector() as selector:
+            selector.register(p.stdout, selectors.EVENT_READ, 'stdout')
+            selector.register(p.stderr, selectors.EVENT_READ, 'stderr')
+
+            while not self.become.check_success(become_stdout):
+                if not selector.get_map():  # we only reach end of stream after all descriptors are EOF
+                    become_error('Premature end of stream')
+
+                if expect_password_prompt and (
+                    self.become.check_password_prompt(become_stdout[last_stdout_prompt_offset:]) or
+                    self.become.check_password_prompt(become_stderr[last_stderr_prompt_offset:])
+                ):
+                    if sent_password:
+                        become_error('Duplicate become password prompt encountered')
+
+                    last_stdout_prompt_offset = len(become_stdout)
+                    last_stderr_prompt_offset = len(become_stderr)
+
+                    password_to_send = to_bytes(self.become.get_option('become_pass') or '') + b'\n'
+
+                    if pty_primary is None:
+                        p.stdin.write(password_to_send)
+                        p.stdin.flush()
+                    else:
+                        os.write(pty_primary, password_to_send)
+
+                    sent_password = True
+
+                remaining_timeout_seconds = self._become_success_timeout - (time.monotonic() - start_seconds)
+                events = selector.select(remaining_timeout_seconds) if remaining_timeout_seconds > 0 else []
+
+                if not events:
+                    # ignoring remaining output after timeout to prevent hanging
+                    become_error('Timed out')
+
+                # read all content (non-blocking) from streams that signaled available input and append to the associated buffer
+                for key, event in events:
+                    obj = t.cast(t.BinaryIO, key.fileobj)
+
+                    if chunk := obj.read():
+                        become_capture[obj] += chunk
+                    else:
+                        selector.unregister(obj)  # EOF on this obj, stop polling it
+
+        os.set_blocking(p.stdout.fileno(), True)
+        os.set_blocking(p.stderr.fileno(), True)
+
+        become_stdout_bytes = bytes(become_stdout)
+        become_stderr_bytes = bytes(become_stderr)
+
+        if self.get_option('become_strip_preamble'):
+            become_stdout_bytes = self.become.strip_become_success(self.become.strip_become_prompt(become_stdout_bytes))
+            become_stderr_bytes = self.become.strip_become_prompt(become_stderr_bytes)
+
+        return become_stdout_bytes, become_stderr_bytes
+
+    @functools.cached_property
+    def _become_success_timeout(self) -> int:
+        """Timeout value for become success in seconds."""
+        if (timeout := self.get_option('become_success_timeout')) < 1:
+            timeout = C.config.get_configuration_definitions('connection', 'local')['become_success_timeout']['default']
+
+        return timeout
 
     def put_file(self, in_path: str, out_path: str) -> None:
         """ transfer a file from local to local """

lib/ansible/plugins/shell/sh.py

@@ -29,6 +29,7 @@ class ShellModule(ShellBase):
 
     # commonly used
     ECHO = 'echo'
+    CD = 'cd'
     COMMAND_SEP = ';'
 
     # How to end lines in a python script one-liner

test/integration/targets/become_su/aliases

@@ -1,3 +1,9 @@
 destructive
-shippable/posix/group3
-context/controller
+shippable/posix/group1
+context/target
+gather_facts/no
+needs/target/setup_become_user_pair
+needs/target/setup_test_user
+setup/always/setup_passlib_controller  # required for setup_test_user
+skip/macos  # requires a TTY
+skip/freebsd  # appears to require a TTY (ignores password input from stdin)

test/integration/targets/become_su/files/sushim.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+# A command wrapper that delegates to su after lowering privilege through an intermediate user (via sudo).
+# This allows forcing an environment that always requires a password prompt for su.
+
+set -eu
+
+args=("${@}")
+
+for i in "${!args[@]}"; do
+  case "${args[$i]}" in
+    "--intermediate-user")
+      intermediate_user_idx="${i}"
+      ;;
+  esac
+done
+
+intermediate_user_name="${args[intermediate_user_idx+1]}"
+
+unset "args[intermediate_user_idx]"
+unset "args[intermediate_user_idx+1]"
+
+exec sudo -n -u "${intermediate_user_name}" su "${args[@]}"

test/integration/targets/become_su/runme.sh

@@ -1,6 +0,0 @@
-#!/usr/bin/env bash
-
-set -eux
-
-# ensure we execute su with a pseudo terminal
-[ "$(ansible -a whoami --become-method=su localhost --become)" != "su: requires a terminal to execute" ]

test/integration/targets/become_su/tasks/main.yml

@@ -0,0 +1,63 @@
+- name: create unprivileged user pair
+  include_role:
+    name: setup_become_user_pair
+    public: true  # this exports target_user_name, target_user_password, intermediate_user_name
+  vars:
+    intermediate_user_groups: "{{ 'staff,admin' if ansible_os_family == 'Darwin' else omit }}"  # this works, but requires a TTY; disabled MacOS su testing in CI for now via aliases
+
+- name: deploy su shim
+  copy:
+    src: sushim.sh
+    dest: /tmp/sushim.sh
+    mode: a+rx
+
+- name: ensure su is setuid on Alpine
+  file:
+    path: /bin/su
+    mode: +s
+  when: ansible_os_family == 'Alpine'
+
+- name: test su scenarios where a password prompt must be encountered
+  vars:
+    ansible_become: yes
+    ansible_become_method: su
+    ansible_become_exe: /tmp/sushim.sh
+    ansible_become_flags: --intermediate-user {{ intermediate_user_name | quote }}  # the default plugin flags are empty
+    ansible_become_user: "{{ target_user_name }}"
+    ansible_become_password: "{{ target_user_password }}"
+  block:
+    - name: basic success check
+      raw: whoami
+      register: success
+      # NOTE: The ssh connection plugin does not properly strip noise from raw stdout, unlike the local connection plugin.
+      #       Once that is fixed, this can be changed to a comparison against stdout, not stdout_lines[-1].
+      failed_when: success.stdout_lines[-1] != target_user_name
+
+    - name: validate that a password prompt is being used
+      vars:
+        ansible_become_password: BOGUSPASS
+      raw: exit 99
+      ignore_errors: yes
+      register: bogus_password
+
+    - assert:
+        that:
+          - |  # account for different failure behavior between local and ssh
+            bogus_password.msg is contains "Incorrect su password" or 
+            bogus_password.msg is contains "Premature end of stream waiting for become success." or
+            (bogus_password.stdout | default('')) is contains "Sorry"
+
+    - name: test wrong su prompt expected
+      raw: echo hi mom from $(whoami)
+      register: wrong_su_prompt
+      vars:
+        ansible_su_prompt_l10n: NOT_A_VALID_PROMPT
+        ansible_local_become_success_timeout: 3  # actual become success timeout
+        ansible_ssh_timeout: 3  # connection timeout, which results in an N+2 second select timeout
+      ignore_errors: yes
+
+    - assert:
+        that:
+          - wrong_su_prompt is failed
+          - ansible_connection != "local" or wrong_su_prompt.msg is contains "Timed out waiting for become success or become password prompt"
+          - ansible_connection != "ssh" or wrong_su_prompt.msg is contains "waiting for privilege escalation prompt"

test/integration/targets/become_sudo/aliases

@@ -0,0 +1,7 @@
+destructive
+shippable/posix/group1
+context/target
+gather_facts/no
+needs/target/setup_become_user_pair
+needs/target/setup_test_user
+setup/always/setup_passlib_controller  # required for setup_test_user

test/integration/targets/become_sudo/files/sudoshim.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+# A command wrapper that delegates to sudo after lowering privilege through an intermediate user (via sudo).
+# This allows forcing an environment that always requires a password prompt for sudo.
+
+set -eu
+
+args=("${@}")
+
+for i in "${!args[@]}"; do
+  case "${args[$i]}" in
+    "--intermediate-user")
+      intermediate_user_idx="${i}"
+      ;;
+  esac
+done
+
+intermediate_user_name="${args[intermediate_user_idx+1]}"
+
+unset "args[intermediate_user_idx]"
+unset "args[intermediate_user_idx+1]"
+
+exec sudo -n -u "${intermediate_user_name}" sudo -k "${args[@]}"

test/integration/targets/become_sudo/tasks/main.yml

@@ -0,0 +1,84 @@
+- name: create unprivileged become user pair
+  include_role:
+    name: setup_become_user_pair
+    public: true
+
+- name: capture config values
+  set_fact:
+    # this needs to be looked up and stored before setting ansible_become_flags
+    default_become_flags: "{{ lookup('config', 'become_flags', plugin_type='become', plugin_name='sudo') }}"
+    intermediate_flags: --intermediate-user {{ intermediate_user_name | quote }}
+
+- name: deploy sudo shim
+  copy:
+    src: sudoshim.sh
+    dest: /tmp/sudoshim.sh
+    mode: a+rx
+
+- name: apply shared become vars to all tasks that use the sudo test shim
+  vars:
+    ansible_become: yes
+    ansible_become_method: sudo
+    ansible_become_user: '{{ target_user_name }}'
+    ansible_become_password: '{{ intermediate_user_password }}'
+    ansible_become_exe: /tmp/sudoshim.sh
+    ansible_become_flags: '{{ default_become_flags }} {{ intermediate_flags }}'
+    ansible_local_become_strip_preamble: true
+  block:
+    - name: basic success check
+      raw: whoami
+      register: success
+      # NOTE: The ssh connection plugin does not properly strip noise from raw stdout, unlike the local connection plugin.
+      #       Once that is fixed, this can be changed to a comparison against stdout, not stdout_lines[-1].
+      failed_when: success.stdout_lines[-1] != target_user_name
+
+    - name: validate that a password prompt is being used and that the shim is invalidating the sudo timestamp
+      vars:
+        ansible_become_password: BOGUSPASS
+      raw: exit 99
+      ignore_errors: true
+      register: bogus_password
+
+    - assert:
+        that:
+          - bogus_password.msg is contains "Incorrect sudo password" or bogus_password.msg is contains "Duplicate become password prompt encountered"
+
+    - name: request sudo chdir to a nonexistent root dir; expected failure
+      raw: echo himom
+      vars:
+        ansible_sudo_chdir: /nonexistent_dir
+      ignore_errors: true
+      register: nonexistent_chdir
+
+    - assert:
+        that:
+          - nonexistent_chdir is failed
+          # deal with inconsistent failure behavior across different connection plugins
+          - (nonexistent_chdir.msg ~ (nonexistent_chdir.stdout | default('')) ~ (nonexistent_chdir.stderr | default(''))) is search "cd.*/nonexistent_dir"
+
+    - name: request sudo chdir to /; cwd should successfully be / before sudo runs
+      raw: echo "CWD IS <$(pwd)>"
+      vars:
+        ansible_sudo_chdir: /
+      register: chdir_root
+
+    - assert:
+        that:
+          - chdir_root.stdout is contains 'CWD IS </>'
+
+    - name: become with custom sudo `--` flags (similar to defaults)
+      vars:
+        ansible_become_flags: --set-home --stdin --non-interactive {{ intermediate_flags }}
+      raw: whoami
+      register: custom_flags
+
+    - name: become with no user
+      vars:
+        ansible_become_user: ""
+      raw: whoami
+      register: no_user
+
+    - assert:
+        that:
+          - custom_flags.stdout.strip() == test_user_name
+          - no_user.stdout.strip() == "root"

test/integration/targets/connection_local/aliases

@@ -1,2 +1,6 @@
 shippable/posix/group5
 needs/target/connection
+needs/target/setup_become_user_pair
+needs/target/setup_test_user
+setup/once/setup_passlib_controller
+destructive

test/integration/targets/connection_local/files/sudoshim.sh

@@ -0,0 +1,88 @@
+#!/usr/bin/env bash
+# A wrapper around `sudo` that replaces the expected password prompt string (if given) with a bogus value.
+# This allows testing situations where the expected password prompt is not found.
+# This wrapper also supports becoming an intermediate user before executing sudo, to support testing as root.
+
+set -eu
+
+args=("${@}")
+intermediate_user_idx=''
+original_prompt=''
+shell_executable=''
+shell_command=''
+original_prompt_idx=''
+
+# some args show up after others, but we need them before processing args that came before them
+for i in "${!args[@]}"; do
+  case "${args[$i]}" in
+    "-p")
+      original_prompt="${args[i+1]}"
+      original_prompt_idx="${i}"
+      ;;
+    "-c")
+      shell_executable="${args[i-1]}"
+      shell_command="${args[i+1]}"
+      ;;
+  esac
+done
+
+for i in "${!args[@]}"; do
+  case "${args[$i]}" in
+    "--inject-stdout-noise")
+      echo "stdout noise"
+      unset "args[i]"
+      ;;
+    "--inject-stderr-noise")
+      echo >&2 "stderr noise"
+      unset "args[i]"
+      ;;
+    "--bogus-prompt")
+      args[original_prompt_idx+1]="BOGUSPROMPT"
+      unset "args[i]"
+      ;;
+    "--intermediate-user")
+      intermediate_user_idx="${i}"
+      ;;
+    "--close-stderr")
+      >&2 echo "some injected stderr, EOF now"
+      exec 2>&-  # close stderr, doesn't seem to work on Ubuntu 24.04 (either not closed or not seen in Python?)
+      unset "args[i]"
+      ;;
+    "--sleep-before-sudo")
+      sleep 3
+      unset "args[i]"
+      ;;
+    "--pretend-to-be-broken-passwordless-sudo")
+      echo '{"hello":"not a module response"}'
+      exit 0
+      ;;
+    "--pretend-to-be-broken-sudo")
+      echo -n "${original_prompt}"
+      read -rs
+      echo
+      echo "success, but not invoking given command"
+      exit 0
+      ;;
+    "--pretend-to-be-sudo")
+      echo -n "${original_prompt}"
+      read -rs
+      echo
+      echo "success, invoking given command"
+      "${shell_executable}" -c "${shell_command}"
+      exit 0
+      ;;
+  esac
+done
+
+if [[ "${intermediate_user_idx}" ]]; then
+  # The current user can sudo without a password prompt, so delegate to an intermediate user first.
+  intermediate_user_name="${args[intermediate_user_idx+1]}"
+
+  unset "args[intermediate_user_idx]"
+  unset "args[intermediate_user_idx+1]"
+
+  exec sudo -n -u "${intermediate_user_name}" sudo -k "${args[@]}"
+else
+  # The current user requires a password to sudo, so sudo can be used directly.
+  exec sudo -k "${args[@]}"
+fi

test/integration/targets/connection_local/runme.sh

@@ -4,7 +4,7 @@ set -eux
 
 group=local
 
-cd ../connection
+pushd ../connection
 
 INVENTORY="../connection_${group}/test_connection.inventory" ./test.sh \
     -e target_hosts="${group}" \
@@ -19,3 +19,7 @@ ANSIBLE_CONNECTION_PLUGINS="../connection_${group}/connection_plugins" INVENTORY
     -e local_tmp=/tmp/ansible-local \
     -e remote_tmp=/tmp/ansible-remote \
     "$@"
+
+popd
+
+ANSIBLE_ROLES_PATH=../ ansible-playbook -i ../../inventory test_become_password_handling.yml "$@"

test/integration/targets/connection_local/test_become_password_handling.yml

@@ -0,0 +1,199 @@
+- hosts: testhost
+  gather_facts: no
+  tasks:
+  - name: skip this test for non-root users
+    block:
+      - debug:
+          msg: Skipping sudo test for non-root user.
+      - meta: end_play
+    when: lookup('pipe', 'whoami') != 'root'
+
+  - name: attempt root-to-root sudo become (no-op, should succeed)
+    vars:
+      ansible_become: yes
+      ansible_become_user: root
+      ansible_become_method: sudo
+    raw: whoami
+    register: root_noop_sudo
+
+  - assert:
+      that:
+        - root_noop_sudo.stdout is contains "root"
+
+  - name: create an unprivileged become user pair
+    include_role:
+      name: setup_become_user_pair
+      public: true
+
+  - name: deploy sudo shim
+    copy:
+      src: sudoshim.sh
+      dest: /tmp/sudoshim.sh
+      mode: u+x
+
+  - set_fact:
+      default_sudo_flags: "{{ lookup('config', 'become_flags', plugin_type='become', plugin_name='sudo') }}"
+
+  - name: apply shared become vars to all tasks that use the sudo test shim
+    vars:
+      ansible_become: yes
+      ansible_become_method: sudo
+      ansible_become_user: '{{ target_user_name }}'
+      ansible_become_password: '{{ target_user_password }}'
+      ansible_become_exe: /tmp/sudoshim.sh
+      ansible_local_become_strip_preamble: true
+      intermediate: "{{ ((' --intermediate-user ' + intermediate_user_name) if intermediate_user_name is defined else '') }}"
+    block:
+      - name: verify stdout/stderr noise is present with preamble strip disabled
+        raw: echo $(whoami) ran
+        vars:
+          ansible_become_flags: "{{ default_sudo_flags ~ intermediate ~ ' --inject-stdout-noise --inject-stderr-noise' }}"
+          ansible_become_password: "{{ intermediate_user_password }}"
+          ansible_local_become_strip_preamble: false
+          ansible_pipelining: true
+        register: preamble_visible
+
+      - name: verify stdout/stderr noise is stripped with preamble strip enabled
+        raw: echo $(whoami) ran
+        vars:
+          ansible_become_flags: "{{ default_sudo_flags ~ intermediate ~ ' --inject-stdout-noise --inject-stderr-noise' }}"
+          ansible_become_password: "{{ intermediate_user_password }}"
+          ansible_pipelining: true
+        register: preamble_stripped
+
+      - assert:
+          that:
+            - preamble_visible.stdout is contains(target_user_name ~ " ran")
+            - preamble_stripped.stdout is contains(target_user_name ~ " ran")
+            - preamble_visible.stdout is contains "stdout noise"
+            - preamble_stripped.stdout is not contains "stdout noise"
+            - preamble_visible.stderr is contains "stderr noise"
+            - preamble_stripped.stderr is not contains "stderr noise"
+
+      - name: verify sudo succeeds with a password (no PTY/pipelined)
+        raw: echo $(whoami) ran
+        vars:
+          ansible_become_flags: "{{ default_sudo_flags ~ intermediate }}"
+          ansible_become_password: "{{ intermediate_user_password }}"
+          ansible_local_become_strip_preamble: false  # allow prompt sniffing from the output
+          ansible_pipelining: true
+        register: success_pipelined
+
+      - assert:
+          that:
+            - success_pipelined.stdout is contains(target_user_name ~ " ran")
+            - success_pipelined.stderr is search 'sudo via ansible.*password\:'
+
+      - name: verify sudo works with a PTY allocated (pipelining disabled)
+        raw: echo $(whoami) ran without pipelining
+        vars:
+          ansible_become_flags: "{{ default_sudo_flags ~ intermediate }}"
+          ansible_become_password: "{{ intermediate_user_password }}"
+          ansible_local_become_strip_preamble: false
+          ansible_pipelining: no  # a PTY is allocated by the local plugin only when pipelining is disabled
+        register: pty_non_pipelined
+
+      - assert:
+          that:
+            - pty_non_pipelined.stdout is contains(test_user_name ~ " ran without pipelining")
+
+      - name: verify early-closed stderr still sees success
+        # this test triggers early EOF (which unregisters the associated selector) on most OSs, but not on Ubuntu 24.04
+        vars:
+          ansible_become_flags: --close-stderr --sleep-before-sudo --pretend-to-be-sudo
+          ansible_local_become_success_timeout: 5
+        raw: echo ran_ok
+        register: stderr_closed
+
+      - assert:
+          that:
+            - stderr_closed.stderr is contains "some injected stderr, EOF now"
+            - stderr_closed.stdout is contains "ran_ok"
+
+      - name: verify timeout handling by setting a sudo prompt that won't trigger password send
+        vars:
+          ansible_become_flags: "{{ default_sudo_flags ~ intermediate }} --bogus-prompt"
+          ansible_local_become_success_timeout: 2
+        raw: exit 99
+        ignore_errors: true
+        register: prompt_timeout
+
+      - assert:
+          that:
+            - prompt_timeout is failed
+            - prompt_timeout.msg is contains "Timed out waiting for become success or become password prompt"
+            - prompt_timeout.msg is contains "BOGUSPROMPT"
+            - prompt_timeout.rc is not defined
+
+      - name: verify sub 1s timeout is always increased
+        vars:
+          ansible_become_flags: "{{ default_sudo_flags ~ ' --sleep-before-sudo' }}"
+          ansible_local_become_success_timeout: 0  # a 0s timeout would always cause select to be skipped in the current impl, but added a 2s sleep in the shim in case that changes
+        raw: whoami
+        register: timeout_increased
+
+      - assert:
+          that:
+            - timeout_increased.stdout is contains target_user_name
+
+      - name: verify handling of premature exit/stream closure
+        vars:
+          ansible_become_exe: /bogus
+        raw: exit 99
+        ignore_errors: true
+        register: early_close
+
+      - assert:
+          that:
+            - early_close is failed
+            - early_close.msg is contains "Premature end of stream"
+
+      - name: verify lack of required password fails as expected
+        raw: exit 99
+        vars:
+          ansible_become_flags: "{{ default_sudo_flags ~ intermediate }}"
+          ansible_become_password: ~
+        ignore_errors: true
+        register: missing_required_password
+
+      - assert:
+          that:
+            - missing_required_password is failed
+            - missing_required_password.msg is contains "password is required"
+
+      - name: verify duplicate password prompts are handled (due to incorrect password)
+        raw: echo hi mom
+        vars:
+          ansible_become_flags: "{{ default_sudo_flags ~ intermediate }}"
+          ansible_become_password: not_the_correct_password
+        ignore_errors: yes
+        register: incorrect_password
+
+      - assert:
+          that:
+            - incorrect_password is failed
+            - incorrect_password.msg is contains "Duplicate become password prompt encountered"
+
+      - name: no error, but no become success message
+        vars:
+          ansible_become_flags: --pretend-to-be-broken-sudo  # handle password prompt, but return no output
+        raw: exit 99  # should never actually run anyway
+        ignore_errors: true
+        register: no_become_success
+
+      - assert:
+          that:
+            - no_become_success is failed
+            - no_become_success.msg is contains "Premature end of stream waiting for become success"
+
+      - name: test broken passwordless sudo
+        raw: echo hi mom
+        vars:
+          ansible_become_flags: --pretend-to-be-broken-passwordless-sudo
+        ignore_errors: yes
+        register: broken_passwordless_sudo
+
+      - assert:
+          that:
+            - broken_passwordless_sudo is failed
+            - broken_passwordless_sudo.msg is contains "not a module response"

test/integration/targets/module_utils/module_utils_basic_setcwd.yml

@@ -4,6 +4,7 @@
     - name: make sure the test user is available
       include_role:
         name: setup_test_user
+        public: yes
 
     - name: verify AnsibleModule works when cwd is missing
       test_cwd_missing:

test/integration/targets/setup_become_user_pair/defaults/main.yml

@@ -0,0 +1,2 @@
+target_user_name: ansibletest0  # target unprivileged user
+intermediate_user_name: ansibletest1  # an intermediate user

test/integration/targets/setup_become_user_pair/tasks/main.yml

@@ -0,0 +1,24 @@
+- name: create an unprivileged user on target
+  include_role:
+    name: setup_test_user
+    public: true
+  vars:
+    test_user_name: '{{ target_user_name }}'
+    test_user_groups: '{{ target_user_groups | default(omit) }}'
+
+- name: capture target user password
+  set_fact:
+    target_user_password: '{{ test_user_plaintext_password }}'
+
+- name: create an intermediate user on target with password-required sudo ability
+  include_role:
+    name: setup_test_user
+    public: true
+  vars:
+    test_user_name: "{{ intermediate_user_name }}"
+    test_user_groups: '{{ intermediate_user_groups | default(omit) }}'
+    test_user_allow_sudo: true
+
+- name: capture config values, intermediate user password from role
+  set_fact:
+    intermediate_user_password: "{{ test_user_plaintext_password }}"

test/integration/targets/setup_test_user/defaults/main.yml

@@ -0,0 +1,5 @@
+# true/false/nopasswd
+test_user_allow_sudo: false
+test_user_name: ansibletest0
+test_user_group: ~
+test_user_groups: ~

test/integration/targets/setup_test_user/handlers/main.yml

@@ -1,6 +1,7 @@
 - name: delete test user
   user:
-    name: "{{ test_user_name }}"
+    name: "{{ item }}"
     state: absent
     remove: yes
     force: yes
+  loop: "{{ delete_users }}"

test/integration/targets/setup_test_user/tasks/default.yml

@@ -1,8 +1,3 @@
-- name: set variables
-  set_fact:
-    test_user_name: ansibletest0
-    test_user_group: null
-
 - name: set plaintext password
   no_log: yes
   set_fact:

test/integration/targets/setup_test_user/tasks/macosx.yml

@@ -1,6 +1,5 @@
 - name: set variables
   set_fact:
-    test_user_name: ansibletest0
     test_user_group: staff
 
 - name: set plaintext password

test/integration/targets/setup_test_user/tasks/main.yml

@@ -13,15 +13,23 @@
       paths:
         - tasks
 
+- set_fact:
+    delete_users: "{{ (delete_users | default([])) + [test_user_name] }}"
+
 - name: create test user
   user:
     name: "{{ test_user_name }}"
     group: "{{ test_user_group or omit }}"
+    groups: "{{ test_user_groups or omit }}"
     password: "{{ test_user_hashed_password or omit }}"
   register: test_user
   notify:
     - delete test user
 
+- name: maybe configure sudo
+  include_tasks: sudo_config.yml
+  when: test_user_allow_sudo != False
+
 - name: run whoami as the test user
   shell: whoami
   vars:

test/integration/targets/setup_test_user/tasks/sudo_config.yml

@@ -0,0 +1,14 @@
+- name: probe for sudoers config path
+  shell: visudo -c
+  ignore_errors: true
+  register: visudo_result
+
+- set_fact:
+    sudoers_path: '{{ ((visudo_result.stdout ~ visudo_result.stderr) | regex_search("(/.*sudoers).*:", "\1"))[0] }}'
+
+- name: allow the user to use sudo {{"with no password" if test_user_allow_sudo == "nopasswd" else "with a password"}}
+  copy:
+    content: |
+      {{ test_user_name }}  ALL=(ALL)  {{"NOPASSWD: " if test_user_allow_sudo == "nopasswd" else ""}} ALL
+    mode: '0440'
+    dest: '{{ sudoers_path ~ ".d/" ~ test_user_name }}'

test/lib/ansible_test/_internal/inventory.py

@@ -2,6 +2,7 @@
 from __future__ import annotations
 
 import shutil
+import sys
 import typing as t
 
 from .config import (
@@ -13,6 +14,11 @@ from .util import (
     exclude_none_values,
 )
 
+from .host_configs import (
+    ControllerConfig,
+    PosixRemoteConfig,
+)
+
 from .host_profiles import (
     ControllerHostProfile,
     ControllerProfile,
@@ -30,12 +36,37 @@ from .ssh import (
 )
 
 
+def get_common_variables(target_profile: HostProfile, controller: bool = False) -> dict[str, t.Any]:
+    """Get variables common to all scenarios, but dependent on the target profile."""
+    target_config = target_profile.config
+
+    if controller or isinstance(target_config, ControllerConfig):
+        # The current process is running on the controller, so consult the controller directly when it is the target.
+        macos = sys.platform == 'darwin'
+    elif isinstance(target_config, PosixRemoteConfig):
+        # The target is not the controller, so consult the remote config for that target.
+        macos = target_config.name.startswith('macos/')
+    else:
+        # The target is a type which either cannot be macOS or for which the OS is unknown.
+        # There is currently no means for the user to override this for user provided hosts.
+        macos = False
+
+    common_variables: dict[str, t.Any] = {}
+
+    if macos:
+        # When using sudo on macOS we may encounter permission denied errors when dropping privileges due to inability to access the current working directory.
+        # To compensate for this we'll perform a `cd /` before running any commands after `sudo` succeeds.
+        common_variables.update(ansible_sudo_chdir='/')
+
+    return common_variables
+
+
 def create_controller_inventory(args: EnvironmentConfig, path: str, controller_host: ControllerHostProfile) -> None:
     """Create and return inventory for use in controller-only integration tests."""
     inventory = Inventory(
         host_groups=dict(
             testgroup=dict(
-                testhost=dict(
+                testhost=get_common_variables(controller_host, controller=True) | dict(
                     ansible_connection='local',
                     ansible_pipelining='yes',
                     ansible_python_interpreter=controller_host.python.path,
@@ -129,7 +160,7 @@ def create_posix_inventory(args: EnvironmentConfig, path: str, target_hosts: lis
         inventory = Inventory(
             host_groups=dict(
                 testgroup=dict(
-                    testhost=dict(
+                    testhost=get_common_variables(target_host) | dict(
                         ansible_connection='local',
                         ansible_pipelining='yes',
                         ansible_python_interpreter=target_host.python.path,
@@ -145,7 +176,7 @@ def create_posix_inventory(args: EnvironmentConfig, path: str, target_hosts: lis
 
         ssh = connections[0]
 
-        testhost: dict[str, t.Optional[t.Union[str, int]]] = dict(
+        testhost: dict[str, t.Optional[t.Union[str, int]]] = get_common_variables(target_host) | dict(
             ansible_connection='ssh',
             ansible_pipelining='yes',
             ansible_python_interpreter=ssh.settings.python_interpreter,

test/lib/ansible_test/_util/target/setup/bootstrap.sh

@@ -229,6 +229,7 @@ prefer-binary = yes
 
     # enable sudo without a password for the wheel group, allowing ansible to use the sudo become plugin
     echo '%wheel ALL=(ALL:ALL) NOPASSWD: ALL' > /usr/local/etc/sudoers.d/ansible-test
+    chmod 440 /usr/local/etc/sudoers.d/ansible-test
 }
 
 bootstrap_remote_macos()

test/units/plugins/become/test_su.py

@@ -7,6 +7,8 @@ from __future__ import annotations
 
 import re
 
+import pytest
+
 from ansible import context
 from ansible.plugins.loader import become_loader, shell_loader
 
@@ -26,3 +28,46 @@ def test_su(mocker, parser, reset_cli_args):
 
     cmd = su.build_become_command('/bin/foo', sh)
     assert re.match(r"""su\s+foo -c '/bin/bash -c '"'"'echo BECOME-SUCCESS-.+?; /bin/foo'"'"''""", cmd)
+
+
+def test_no_cmd() -> None:
+    cmd = ''
+
+    assert become_loader.get('su').build_become_command(cmd, shell_loader.get('sh')) is cmd
+
+
+@pytest.mark.parametrize("prefix, prompt", (
+    ("", "Password:"),
+    (" ", "Password :"),
+    ("\n", "Password ："),
+    ("x", "Password ："),
+    ("", "口令:"),
+    (" ", "口令 :"),
+    ("\n", "口令 ："),
+    ("x", "口令 ："),
+))
+def test_check_password_prompt_success(prefix: str, prompt: str) -> None:
+    become = become_loader.get('su')
+
+    assert become.check_password_prompt((prefix + prompt).encode()) is True
+    assert become.prompt == prompt
+
+
+@pytest.mark.parametrize("data", (
+    "Password",
+    "Passwort",
+    "Pass:",
+))
+def test_check_password_prompt_failure(data: str) -> None:
+    become = become_loader.get('su')
+
+    assert become.check_password_prompt(data.encode()) is False
+    assert become.prompt == ''
+
+
+def test_check_password_prompt_escaping(mocker) -> None:
+    become = become_loader.get('su')
+
+    mocker.patch.object(become, 'get_option', return_value=['(invalid regex'])
+
+    assert become.check_password_prompt('(invalid regex:') is True

test/units/plugins/become/test_sudo.py

@@ -5,9 +5,13 @@
 
 from __future__ import annotations
 
+import pytest
 import re
 
+from pytest_mock import MockerFixture
+
 from ansible import context
+from ansible.errors import AnsibleError
 from ansible.plugins.loader import become_loader, shell_loader
 
 
@@ -63,3 +67,37 @@ def test_sudo(mocker, parser, reset_cli_args):
 
     cmd = sudo.build_become_command('/bin/foo', sh)
     assert re.match(r"""sudo\s+-C5\s-s\s-H\s+-p "\[sudo via ansible, key=.+?\] password:" -u foo /bin/bash -c 'echo BECOME-SUCCESS-.+? ; /bin/foo'""", cmd), cmd
+
+
+@pytest.mark.parametrize("del_attr_name, expected_error_pattern", (
+    ("ECHO", ".*does not support become.*missing the 'ECHO' attribute"),  # BecomeBase
+    ("CD", ".*does not support sudo chdir.*missing the 'CD' attribute"),  # sudo
+))
+def test_invalid_shell_plugin(del_attr_name: str, expected_error_pattern: str, mocker: MockerFixture) -> None:
+    def badprop(_self):
+        raise AttributeError(del_attr_name)
+
+    sh = shell_loader.get('sh')
+    mocker.patch.object(type(sh), del_attr_name, property(fget=badprop))
+
+    sudo = become_loader.get('sudo')
+    sudo.set_options(direct=dict(sudo_chdir='/'))
+
+    with pytest.raises(AnsibleError, match=expected_error_pattern):
+        sudo.build_become_command('/stuff', sh)
+
+
+def test_no_flags() -> None:
+    sudo = become_loader.get('sudo')
+    sudo.set_options(direct=dict(become_pass='x', become_flags=''))
+
+    result = sudo.build_become_command('/stuff', shell_loader.get('sh'))
+
+    # ensure no flags were in the final command other than -p and -u
+    assert re.search(r'''^sudo +-p "[^"]*" -u root '[^']*'$''', result)
+
+
+def test_no_cmd() -> None:
+    cmd = ''
+
+    assert become_loader.get('sudo').build_become_command(cmd, shell_loader.get('sh')) is cmd