Re: [PATCH 0/3] Apple M1 DART IOMMU driver

[Arnd Bergmann]

On Fri, Mar 26, 2021 at 6:28 PM Mark Kettenis <mark.kettenis@xxxxxxxxx> wrote:

> I haven't figured out how the bypass stuff really works.  Corellium
> added support for it in their codebase when they added support for
> Thunderbolt, and some of the DARTs that seem to be related to
> Thunderbolt do indeed have a "bypass" property.  But it is unclear to
> me how the different puzzle pieces fit together for Thunderbolt.

As a general observation, bypass mode for Thunderbolt is what enabled
the http://thunderclap.io/ attack. This is extremely useful for debugging
a running kernel from another machine, but it's also something that
should never be done in a production kernel.

         Arnd