Given the following code containing errors, provide Common Weakness Enumeration (CWE) identifiers and corresponding messages in JSON format. Each identified weakness should have a unique entry in the JSON array.
    Code: psutil_users(PyObject *self, PyObject *args) {
    PyObject *py_retlist = PyList_New(0);
    PyObject *py_username = NULL;
    PyObject *py_tty = NULL;
    PyObject *py_hostname = NULL;
    PyObject *py_tuple = NULL;

    if (py_retlist == NULL)
        return NULL;

#if (defined(__FreeBSD_version) && (__FreeBSD_version < 900000)) || PSUTIL_OPENBSD
    struct utmp ut;
    FILE *fp;

    fp = fopen(_PATH_UTMP, "r");
    if (fp == NULL) {
        PyErr_SetFromErrnoWithFilename(PyExc_OSError, _PATH_UTMP);
        goto error;
    }

    while (fread(&ut, sizeof(ut), 1, fp) == 1) {
        if (*ut.ut_name == '\0')
            continue;
        py_username = PyUnicode_DecodeFSDefault(ut.ut_name);
        if (! py_username)
            goto error;
        py_tty = PyUnicode_DecodeFSDefault(ut.ut_line);
        if (! py_tty)
            goto error;
        py_hostname = PyUnicode_DecodeFSDefault(ut.ut_host);
        if (! py_hostname)
            goto error;
        py_tuple = Py_BuildValue(
            "(OOOfi)",
            py_username,        // username
            py_tty,             // tty
            py_hostname,        // hostname
            (float)ut.ut_time,  // start time
#ifdef PSUTIL_OPENBSD
            -1                  // process id (set to None later)
#else
            ut.ut_pid           // process id
#endif
        );
        if (!py_tuple) {
            fclose(fp);
            goto error;
        }
        if (PyList_Append(py_retlist, py_tuple)) {
            fclose(fp);
            goto error;
        }
        Py_DECREF(py_username);
        Py_DECREF(py_tty);
        Py_DECREF(py_hostname);
        Py_DECREF(py_tuple);
    }

    fclose(fp);
#else
    struct utmpx *utx;
    setutxent();
    while ((utx = getutxent()) != NULL) {
        if (utx->ut_type != USER_PROCESS)
            continue;
        py_username = PyUnicode_DecodeFSDefault(utx->ut_user);
        if (! py_username)
            goto error;
        py_tty = PyUnicode_DecodeFSDefault(utx->ut_line);
        if (! py_tty)
            goto error;
        py_hostname = PyUnicode_DecodeFSDefault(utx->ut_host);
        if (! py_hostname)
            goto error;
        py_tuple = Py_BuildValue(
            "(OOOfi)",
            py_username,   // username
            py_tty,        // tty
            py_hostname,   // hostname
            (float)utx->ut_tv.tv_sec,  // start time
#ifdef PSUTIL_OPENBSD
            -1             // process id (set to None later)
#else
            utx->ut_pid    // process id
#endif
        );

        if (!py_tuple) {
            endutxent();
            goto error;
        }
        if (PyList_Append(py_retlist, py_tuple)) {
            endutxent();
            goto error;
        }
        Py_DECREF(py_username);
        Py_DECREF(py_tty);
        Py_DECREF(py_hostname);
        Py_DECREF(py_tuple);
    }

    endutxent();
#endif
    return py_retlist;

error:
    Py_XDECREF(py_username);
    Py_XDECREF(py_tty);
    Py_XDECREF(py_hostname);
    Py_XDECREF(py_tuple);
    Py_DECREF(py_retlist);
    return NULL;
} ; Sample JSON Format Confermily Expected output: "examples" => "cwe": "xxx"; "message": "xxx"
    
 'cwe': ['CWE-415'], 'message': 'Use Py_CLEAR instead of Py_DECREF to also set the variable to NULL (#1616)

These files contain loops that convert system data into python objects
and during the process they create objects and dereference their
refcounts after they have been added to the resulting list.

However, in case of errors during the creation of those python objects,
the refcount to previously allocated objects is dropped again with
Py_XDECREF, which should be a no-op in case the paramater is NULL. Even
so, in most of these loops the variables pointing to the objects are
never set to NULL, even after Py_DECREF is called at the end of the loop
iteration. This means, after the first iteration, if an error occurs
those python objects will get their refcount dropped two times,
resulting in a possible double-free.'