Potential integer overflow in instrumentation.c

[rialbat]

The arithmetic expression to * (int)sizeof(_Py_CODEUNIT) can overflow if the number of instructions in a function exceeds MAX_INT / 2, as to represents the instruction offset and sizeof(_Py_CODEUNIT) is 2.

cpython/Python/instrumentation.c

Line 1239 in 4b44b34

PyObject *to_obj = PyLong_FromLong(to * (int)sizeof(_Py_CODEUNIT));

Linked PRs

• gh-135177: Add assert to catch potential overflow #135179
• gh-135177: Raise OverflowError in _Py_call_instrumentation_jump to handle potential integer overflow #135202

[markshannon]

The number of instructions will not exceed MAX_INT / 2, the bytecode compiler ensures that.