_testbuffer.c's initialization does not handle errors

[sobolevn]

Bug report

I found three problematic places:

cpython/Modules/_testbuffer.c

Lines 2841 to 2844 in a768e12

	Struct = PyObject_GetAttrString(structmodule, "Struct");
	calcsize = PyObject_GetAttrString(structmodule, "calcsize");
	if (Struct == NULL || calcsize == NULL)
	return NULL;

Here the first AttributeError can be swallowed by the second one.

cpython/Modules/_testbuffer.c

Lines 2850 to 2879 in a768e12

	PyModule_AddIntMacro(m, ND_MAX_NDIM);
	PyModule_AddIntMacro(m, ND_VAREXPORT);
	PyModule_AddIntMacro(m, ND_WRITABLE);
	PyModule_AddIntMacro(m, ND_FORTRAN);
	PyModule_AddIntMacro(m, ND_SCALAR);
	PyModule_AddIntMacro(m, ND_PIL);
	PyModule_AddIntMacro(m, ND_GETBUF_FAIL);
	PyModule_AddIntMacro(m, ND_GETBUF_UNDEFINED);
	PyModule_AddIntMacro(m, ND_REDIRECT);
	PyModule_AddIntMacro(m, PyBUF_SIMPLE);
	PyModule_AddIntMacro(m, PyBUF_WRITABLE);
	PyModule_AddIntMacro(m, PyBUF_FORMAT);
	PyModule_AddIntMacro(m, PyBUF_ND);
	PyModule_AddIntMacro(m, PyBUF_STRIDES);
	PyModule_AddIntMacro(m, PyBUF_INDIRECT);
	PyModule_AddIntMacro(m, PyBUF_C_CONTIGUOUS);
	PyModule_AddIntMacro(m, PyBUF_F_CONTIGUOUS);
	PyModule_AddIntMacro(m, PyBUF_ANY_CONTIGUOUS);
	PyModule_AddIntMacro(m, PyBUF_FULL);
	PyModule_AddIntMacro(m, PyBUF_FULL_RO);
	PyModule_AddIntMacro(m, PyBUF_RECORDS);
	PyModule_AddIntMacro(m, PyBUF_RECORDS_RO);
	PyModule_AddIntMacro(m, PyBUF_STRIDED);
	PyModule_AddIntMacro(m, PyBUF_STRIDED_RO);
	PyModule_AddIntMacro(m, PyBUF_CONTIG);
	PyModule_AddIntMacro(m, PyBUF_CONTIG_RO);
	PyModule_AddIntMacro(m, PyBUF_READ);
	PyModule_AddIntMacro(m, PyBUF_WRITE);

Here PyModule_AddIntMacro can return an error. It is not checked.

cpython/Modules/_testbuffer.c

Lines 2829 to 2835 in a768e12

	Py_SET_TYPE(&NDArray_Type, &PyType_Type);
	Py_INCREF(&NDArray_Type);
	PyModule_AddObject(m, "ndarray", (PyObject *)&NDArray_Type);
	Py_SET_TYPE(&StaticArray_Type, &PyType_Type);
	Py_INCREF(&StaticArray_Type);
	PyModule_AddObject(m, "staticarray", (PyObject *)&StaticArray_Type);

PyModule_AddObject can also return an error.

I have a PR ready.

Linked PRs

• gh-114670: Fix _testbuffer module initialization #114672
• [3.11] gh-114670: Fix _testbuffer module initialization (GH-114672) #115271
• [3.12] gh-114670: Fix _testbuffer module initialization (GH-114672) #115272

[sobolevn]

Done! 🎉