QAudioInputPrivate::read crashes in Windows. The "len" argument is not respected and this causes a access violation. The following code will reproduce the error (parts are missing obviously):

// start the device
QAudioInput *input = new QAudioInput;
QIODevice *inputIO = input->start();

// function after inputIO readyRead is emitted
int bytes = input->bytesReady();

if (bytes > 0) {
QByteArray data;
data.resize(bytes);
inputIO->read(data.data(), bytes);
}

In the QAudioInputPrivate::read function "len" needs to be checked against the total bytes written to the buffer. It currently only checks against the number of bytes read for each iteration of the while loop.