Restrict role param vars to tasks within that role

Fixes #12460

lib/ansible/playbook/role/__init__.py

@@ -254,21 +254,23 @@ class Role(Base, Become, Conditional, Taggable):
         default_vars = combine_vars(default_vars, self._default_vars)
         return default_vars
 
-    def get_inherited_vars(self, dep_chain=[]):
+    def get_inherited_vars(self, dep_chain=[], include_params=True):
         inherited_vars = dict()
 
         for parent in dep_chain:
             inherited_vars = combine_vars(inherited_vars, parent._role_vars)
+            if include_params:
                 inherited_vars = combine_vars(inherited_vars, parent._role_params)
         return inherited_vars
 
-    def get_vars(self, dep_chain=[]):
+    def get_vars(self, dep_chain=[], include_params=True):
-        all_vars = self.get_inherited_vars(dep_chain)
+        all_vars = self.get_inherited_vars(dep_chain, include_params=include_params)
 
         for dep in self.get_all_dependencies():
-            all_vars = combine_vars(all_vars, dep.get_vars())
+            all_vars = combine_vars(all_vars, dep.get_vars(include_params=include_params))
 
         all_vars = combine_vars(all_vars, self._role_vars)
+        if include_params:
             all_vars = combine_vars(all_vars, self._role_params)
 
         return all_vars

lib/ansible/vars/__init__.py

@@ -256,7 +256,7 @@ class VariableManager:
 
             if not C.DEFAULT_PRIVATE_ROLE_VARS:
                 for role in play.get_roles():
-                    all_vars = combine_vars(all_vars, role.get_vars())
+                    all_vars = combine_vars(all_vars, role.get_vars(include_params=False))
 
         if task:
             if task._role: