java-topology/defects/pytorch/pytorch-diamond-recursion-CLEAN.md

Diamond Recursion Scan (pytorch) — CLEAN (deeper scan)

Scan date: 2026-03-29 Pattern: Recursive cycle/dependency check without visited set (CWE-407 diamond recursion, O(2^D))

Files examined

• torch/_inductor/scheduler.py:topological_sort_schedule — uses seen = OrderedSet() — CLEAN
• torch/_inductor/memory.py:topological_sort_lpmf — uses seen OrderedSet — CLEAN
• torch/_inductor/memory.py:dfs_visit — uses color dict (WHITE/GRAY/BLACK) — CLEAN
• torch/_inductor/augmented_graph_helper.py:_get_all_ancestors — iterative with ancestors set — CLEAN
• torch/_inductor/fx_passes/overlap_scheduling.py:_collect_node_ancestors — iterative DP — CLEAN
• torch/_dynamo/graph_deduplication.py:_has_cycle — delegates to topological sort — CLEAN
• torch/package/_digraph.py — uses networkx DiGraph — CLEAN
• torch/utils/data/graph.py:traverse_dps — no DAG traversal without visited — CLEAN
• torch/autograd/ — engine is C++, Python wrappers don't do DAG traversal — CLEAN

Verdict: CLEAN — no diamond recursion CWE-407 found beyond existing pytorch-0001..0003