How can I handle asynchronous in http requests of QT?

I'm trying to send http requests in QT5 but I can't find a solution

There is a class I use to handle all requests

class ClientCore : public QObject
{
    Q_OBJECT

public:
...
    QNetworkReply *sendGetRequset(QUrl &url);
...

private:
...
    QNetworkAccessManager *manager;
    QNetworkRequest request;
    QNetworkReply *reply;
};

The function

QNetworkReply *ClientCore::sendGetRequset(QUrl &url)

accepts a reference of a QUrl object as parameter, uses it as the target address and send the request

QEventLoop loop;
QTimer timer;
timer.setInterval(RETRYTIME);   // timeout after 8 seconds
timer.setSingleShot(true);      
connect(&timer, SIGNAL(timeout()), &loop, SLOT(quit()));
connect(reply, SIGNAL(finished()), &loop, SLOT(quit()));

request.setUrl(url);
int total = 1;      //try at most three times if failed
while (total <= 3) {
    reply = manager->get(request);
    total++;
    timer.start();
    loop.exec();    
    if (timer.isActive() && reply->error() == QNetworkReply::NoError) { 
        return reply;
    } else {        
        reply->abort();
        timer.stop();
    }
}
return nullptr;

I wonder that is there any hidden asynchronous danger which means the variable "reply" may be refreshed before returned?
For example, if I have serval pushbuttons on the UI layer, and each of them uses this function like below

QNetworkReply *reply = clientCore->sentGetRequset(url);
if (reply != nullptr){
    //much to do
}

In addition, is there any way I can improve these codes?