gh-154670: Fix use-after-free in itertools.count via re-entrant step#154671
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tonghuaroot wants to merge 4 commits into
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gh-154670: Fix use-after-free in itertools.count via re-entrant step#154671tonghuaroot wants to merge 4 commits into
tonghuaroot wants to merge 4 commits into
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kumaraditya303
approved these changes
Jul 25, 2026
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count_nextlong()borrowslz->long_cntwithoutPy_INCREF, then callsPyNumber_Addwhich can re-enter viastep.__radd__. The innernext()returns the same pointer; when the caller releases it, the outer call holds a dangling pointer.Fix:
Py_NewRefthe borrowed value before the callback,Py_SETREFfor the swap.