They all look as false positive. For example:

        if (_Unpickler_Read(self, &pdata, size) < 0)
            return -1;
        value = _PyLong_FromByteArray((unsigned char *)pdata, (size_t)size,
                                      1 /* little endian */ , 1 /* signed */ );

gcc is enough smart to determine that pdata can be not initialized in _Unpickler_Read(), but not enough smart to determine that in this case _Unpickler_Read() always returns -1.