[3.14] gh-148660: Fix use-after-free in OrderedDict.copy() on reentrant mutation (GH-151573)#152541
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…t mutation (pythonGH-151573) * pythongh-148660: Fix use-after-free in OrderedDict.copy() on reentrant 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. * pythongh-148660: fix NEWS nit, suppress undocumented OrderedDict.copy xref (cherry picked from commit 7d128e3) Co-authored-by: Gregory P. Smith <68491+gpshead@users.noreply.github.com>
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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.
(cherry picked from commit 7d128e3)
Co-authored-by: Gregory P. Smith 68491+gpshead@users.noreply.github.com