Potential memory leak after CFSocketCreateWithNative

This is driving me mad! What is wrong here?

There is no guarantee that the reference hasn't been modified by another thread. Assign the socket to a local variable on creation, modify it, set the property, and release the local variable:

CFSocketRef socket = CFSocketCreateWithNative(...);
if (socket) {
    ...
    self.listeningSocket = socket;
    CFRelease(socket);
}