Fix crash in c-extension-no-member check

ChangeLog

@@ -64,6 +64,11 @@ Release date: TBA
 
   Closes #1555
 
+* Fix crash (in unreleased development) in ``c-extension-no-member`` check when inspecting living objects
+  with ``extension-pkg-allow-list``.
+
+  Closes #6221
+
 * The concept of checker priority has been removed.
 
 * ``duplicate-argument-name`` now only raises once for each set of duplicated arguments.

pylint/checkers/typecheck.py

@@ -1053,6 +1053,10 @@ def visit_attribute(self, node: nodes.Attribute) -> None:
                 missingattr.add((owner, name))
                 continue
             else:
+                if isinstance(attr_nodes, nodes.NodeNG):
+                    # If owner was a living object, attr_nodes might be a node itself
+                    # Faster than retrieving the module object and testing _is_c_extension()
+                    break
                 for attr_node in attr_nodes:
                     attr_parent = attr_node.parent
                     # Skip augmented assignments