gh-148660: Fix use-after-free in OrderedDict.copy() on reentrant mutation#151573
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gpshead wants to merge 1 commit into
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gh-148660: Fix use-after-free in OrderedDict.copy() on reentrant mutation#151573gpshead wants to merge 1 commit into
gpshead wants to merge 1 commit into
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…t mutation OrderedDict.copy() walks the internal linked list while building the new dict. The loop body can run arbitrary Python (a key's __eq__/__hash__, or a subclass __getitem__/__setitem__) which can clear the source dict and free the nodes being iterated. Detect this the same way OrderedDict.__eq__ already does (pythongh-119004): snapshot od_state before the loop, hold a strong reference to the key and read the hash before any reentrant call, and raise RuntimeError if the state changed before advancing to the next node.
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OrderedDict.copy() walks the internal linked list while building the new dict. The loop body can run arbitrary Python (a key's
__eq__/__hash__, or a subclass__getitem__/__setitem__) which can clear the source dict and free the nodes being iterated.Detect this the same way OrderedDict.
__eq__already does (gh-119004): snapshot od_state before the loop, hold a strong reference to the key and read the hash before any reentrant call, and raise RuntimeError if the state changed before advancing to the next node.