How to add one onClick Event to multiple UI buttons

Hello, I must be missing something essential here. This is what I've tried:

 void Start()
 {
         // Assign the callback to all buttons
         foreach(Button subbutton in canvas.transform.GetComponentsInChildren<Button>())
         {
             if(subbutton.tag == "subbutton")
             {
                 subbutton.onClick.AddListener(() => { OnSubButtonPressed(subbutton); });
             }
         }
 }

 public void OnSubButtonPressed(Button button)
 {
         // Shows the last button from the foreach loop, no matter what button I click.
         Debug.Log("button '" + button + "' was pressed");
 }

Now, the problem is that each button callback has the last button from the array (GetComponentsInChildren()) assigned as parameter, but in the foreach loop I want to attach the same callback to every button with the current button as a parameter. Is that even possible? Or is there another way to achieve that?