slackpkg upgrade-all for -current, and now no keyboard, mouse or network

I have a fairly clean slackware-current box. Today I did slackpkg upgrade-all. After the reboot, I have no mouse or keyboard control, and can't access it via network. I can't login, can't ping it, can't ssh into it. The mouse does not light up. Keyboard capslock does not toggle. It just sits there at the login prompt, cursor flashing, and dead in the water.

Is there any way to recover from this? Or do I have to do wipe/reinstall Slackware?