gh-143635: Fix crash in _Py_typing_type_repr
#143670
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sobolevn
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needs backport to 3.13
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This needs NEWS since it fixes a user-visible crash. |
JelleZijlstra
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Jan 14, 2026
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JelleZijlstra
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Actually this is incorrect. The crash can be triggered if the list is cleared while we're iterating over it in ga_repr_items_list. INCREFing here is insufficient to protect us because the item may not be valid in the first place any more by the time we receive it.
My repro case in #143823 makes this clearer.
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Thank you! I refactored the PR to include the fix for the third case. |
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I also added one more test case for a second possible crash in the same function.
_Py_typing_type_reprvia re-entrant__origin__lookup duringGenericAliasrepr #143635