demonstrate the bug?

Author: maurycy

Lib/test/test_external_inspection.py

@@ -3660,5 +3660,36 @@ def test_get_stats_disabled_raises(self):
             client_socket.sendall(b"done")
 
 
+@requires_remote_subprocess_debugging()
+@unittest.skipUnless(sys.platform == "linux", "requires /proc/self/mem")
+@unittest.skipIf(
+    not PROCESS_VM_READV_SUPPORTED,
+    "Run on Linux with process_vm_readv support",
+)
+class TestInvalidDebugOffsets(RemoteInspectionTestBase):
+    @skip_if_not_supported
+    @unittest.skipUnless(
+        os.environ.get("PYTHON_REMOTE_DEBUG_UBSAN_PROBE") == "1",
+        "with UBSan probe",
+    )
+    def test_ubsan_probe_misaligned_interpreter_state_id_offset(self):
+        poison_code = textwrap.dedent(
+            """\
+            interpreter_state_offset = 8 + 8 + 8 + 3 * 8
+            interpreter_id_offset = interpreter_state_offset + 8
+            fd = os.open(f"/proc/{pid}/mem", os.O_WRONLY)
+            os.lseek(fd, addr + interpreter_id_offset, 0)
+            os.write(fd, struct.pack("<Q", 1))
+            os.close(fd)
+            """
+        )
+
+        with self._poisoned_debug_offsets_process(poison_code) as (_, info):
+            with self.assertRaisesRegex(RuntimeError, "Invalid debug offsets"):
+                unwinder = RemoteUnwinder(info["pid"], debug=True)
+                stack_trace = unwinder.get_stack_trace()
+                self.assertTrue(stack_trace)
+
+
 if __name__ == "__main__":
     unittest.main()