Can I use a surge protector with an adapter on travel?
If the adapter passive, it probably can handle use anywhere.

Cheap surge suppressors typically just put MOVs (metal oxide varistors) across the inputs, so any voltage over the nominal is shorted through the varistor and the voltage your electronics see never exceeds that voltage.

That said, a suppressor made for US markets will be built with varistors that clamp voltage somewhere over a bit over 120 Vac. In much of the world, wall voltage is 220+ Vac, so its possible that a US market suppressor will immediately fail in, say, 220 V Europe.

Conversely, using a suppressor designed for 220 Vac regions will not give you much protection in the US, since a spike up to, say, 200 Vac in the US (which would fry many devices) would not be caught by a Euro suppressor.