[ojn]

FireWire (or at least OHCI-1394) had another fun feature: It exposed memory from the machine over the bus.

https://www.kernel.org/doc/html/latest/core-api/debugging-vi...

[EDIT: This was 100% feature, not bug]

[orev]

This (Direct Memory Access - DMA) is still a feature of Thunderbolt (which is really just an evolution of FireWire), and thunderbolt is coming to USB4.