Prevent ansible_failed_task from further templating (#74290)

* Prevent ansible_failed_task from further templating

Fixes #74036

* Add changelog

changelogs/fragments/74036-unsafe-ansible_failed_task.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - Prevent ``ansible_failed_task`` from further templating (https://github.com/ansible/ansible/issues/74036)

lib/ansible/plugins/strategy/__init__.py

@@ -50,6 +50,7 @@ from ansible.playbook.task_include import TaskInclude
 from ansible.plugins import loader as plugin_loader
 from ansible.template import Templar
 from ansible.utils.display import Display
+from ansible.utils.unsafe_proxy import wrap_var
 from ansible.utils.vars import combine_vars
 from ansible.vars.clean import strip_internal_keys, module_response_deepcopy
 
@@ -572,7 +573,7 @@ class StrategyBase:
                         self._variable_manager.set_nonpersistent_facts(
                             original_host.name,
                             dict(
-                                ansible_failed_task=original_task.serialize(),
+                                ansible_failed_task=wrap_var(original_task.serialize()),
                                 ansible_failed_result=task_result._result,
                             ),
                         )

test/integration/targets/blocks/runme.sh

@@ -103,3 +103,5 @@ rm -f role_complete_test.out
 
 # test notify inheritance
 ansible-playbook inherit_notify.yml "$@"
+
+ansible-playbook unsafe_failed_task.yml "$@"

test/integration/targets/blocks/unsafe_failed_task.yml

@@ -0,0 +1,17 @@
+- hosts: localhost
+  gather_facts: false
+  vars:
+    - data: {}
+  tasks:
+    - block:
+        - name: template error
+          debug:
+            msg: "{{ data.value }}"
+      rescue:
+        - debug:
+            msg: "{{ ansible_failed_task.action }}"
+
+        - assert:
+            that:
+              - ansible_failed_task.name == "template error"
+              - ansible_failed_task.action == "debug"