Accessing session data in passport js

passport.js

var LocalStrategy    = require('passport-local').Strategy;
var FacebookStrategy = require('passport-facebook').Strategy;
var User = require('../models/User.js');
var configAuth = require('./auth.js');

module.exports = function(passport) {

    passport.serializeUser(function(user, done) {
        done(null, user.id);
    });

    passport.deserializeUser(function(id, done) {
        User.findOne({ 'id' : id }, function(err, user) {
            done(err, user);
        });
    });


    // =========================================================================
    // FACEBOOK ================================================================
    // =========================================================================
    passport.use(new FacebookStrategy({
        // pull in our app id and secret from our auth.js file
        clientID        : configAuth.facebookAuth.clientID, clientSecret    : configAuth.facebookAuth.clientSecret,
        callbackURL     : configAuth.facebookAuth.callbackURL, profileFields   : configAuth.facebookAuth.profileFields
    },

    // facebook will send back the token and profile
    function(token, refreshToken, profile, done) {

        // asynchronous
        process.nextTick(function() {

            // find the user in the database based on their facebook id
            User.findOne({ 'facebook.facebook_id' : profile.id }, function(err, user) {

                // if there is an error, stop everything and return that
                if (err)
                    return done(err);

                // if the user is found, then log them in
                if (user) {
                    return done(null, user); // user found, return that user
                } else {  // if there is no user found with that facebook id, create them

                    var newUser = new User();
                    

                    // set all of the facebook information in our user model
                    newUser.facebook.facebook_id    = profile.id; // set the users facebook id
                    newUser.facebook.facebook_token = token; // we will save the token that facebook provides to the user
                    newUser.firstname  = profile.name.givenName; // store first
                   ///////////////////////////////////////////////////////////////////////////////////
                   //////////////////////////////////  HERE /////////////////////////////////////////
                   /////////////////////////////////////////////////////////////////////////////////
                    newUser.utm.campaign_source = req.session.campaign_source;
                    newUser.utm.campaign_medium = req.session.campaign_medium;
                    newUser.utm.campaign_name = req.session.campaign_name;
                    newUser.utm.campaign_content = req.session.campaign_content;
                    newUser.utm.referral_code = req.session.referral_code;

                    newUser.save(function(err) {
                        if (err)
                            throw err;

                        // if successful, return the new user
                        return done(null, newUser);
                    });
                }

            });
        });

    }));

};