Do not decref borrowed module dict reference - #264
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PyModule_GetDict() returns a borrowed reference. The InitOperators() error path called Py_XDECREF(d) on it, dropping the module dict's refcount one too many. That can free the dict prematurely and lead to a use-after-free. Remove the erroneous decref; only the owned module object m needs releasing on this path.
antonwolfy
requested review from
jharlow-intel,
ndgrigorian,
vlad-perevezentsev and
xaleryb
as code owners
August 31, 2026 14:18
ndgrigorian
approved these changes
Aug 31, 2026
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Summary
PyModule_GetDict()returns a borrowed reference. InPyInit__ufuncs, theInitOperators()error path calledPy_XDECREF(d)on that borrowed reference, dropping the module dict's refcount one too many. This can free the dict prematurely and lead to a use-after-free (e.g. on the next access or during interpreter shutdown).Only the module object
m— the owned reference fromPyModule_Create()— needs to be released on this error path. This removes the erroneousPy_XDECREF(d).Notes
Latent, pre-existing bug; only reachable when
InitOperators()fails at module init.