Annotation should be deepcopied

torch/_functorch/_aot_autograd/utils.py

@@ -3,6 +3,7 @@
 Contains various utils for AOTAutograd, including those for handling collections.
 """
 
+import copy
 import dataclasses
 import logging
 import operator
@@ -459,7 +460,9 @@ def _copy_metadata_to_bw_nodes_in_subgraph(
             node.meta["fwd_nn_module_stack"] = fwd_node.meta.get("nn_module_stack")
             node.meta["fwd_source_fn_stack"] = fwd_node.meta.get("source_fn_stack")
             # TODO: better to change to a specific field of custom?
-            node.meta["custom"] = fwd_node.meta.get("custom")
+            custom = fwd_node.meta.get("custom")
+            if custom is not None:
+                node.meta["custom"] = copy.deepcopy(custom)
 
 
 def copy_fwd_metadata_to_bw_nodes(fx_g: torch.fx.GraphModule) -> None: