My wife had exactly the same experience last night with her 2015 MacBook Pro. She was getting regular kernel panics so I went to the updater to see if it was just a software problem. It says Safari is out of date so I clicked "update", and literally 5 hours later (I clicked the button around 20:00, it didn't finish until sometime after 01:00) it finally finished. I'd thought I had it set up to auto-update, but apparently it got stuck on something.