GeezerVison

Three bugs in the cross-interpreter data subsystem are fixed by this patch: a use-after-free in _ensure_notshareableerror where control falls through to code that dereferences a ctx pointer after ownership of the referenced object was transferred to the thread state via _PyErr_SetRaisedException, a leaked exception in _PyXI_UnwrapNotShareableError where _PyXI_InitFailure can fail under low-memory conditions leaving the exception removed from the thread error indicator and never restored, and a use-after-free in _get_xidata where obj is passed to _set_xid_lookup_failure for error-string formatting after it has already been released with Py_DECREF, meaning a concurrent deallocation would dereference a freed pointer.

• Issue: Umbrella issue: bugs found using cpython-review-toolkit #146102