diff --git a/libcxx/utils/libcxx/test/executor.py b/libcxx/utils/libcxx/test/executor.py
--- a/libcxx/utils/libcxx/test/executor.py
+++ b/libcxx/utils/libcxx/test/executor.py
@@ -158,10 +158,18 @@
                 srcs.extend(file_deps)
                 dsts.extend(dev_paths)
             self.copy_in(srcs, dsts)
+
+            # When testing executables that were cross-compiled on Windows for
+            # Linux, we may need to explicitly set the execution permission to
+            # avoid the 'Permission denied' error:
+            chmod_cmd = ['chmod', '+x', target_exe_path]
+
             # TODO(jroelofs): capture the copy_in and delete_remote commands,
             # and conjugate them with '&&'s around the first tuple element
             # returned here:
-            return self._execute_command_remote(cmd, target_cwd, env)
+            return self._execute_command_remote(chmod_cmd + ['&&'] + cmd,
+                                                target_cwd,
+                                                env)
         finally:
             if target_cwd:
                 self.delete_remote(target_cwd)