On Thu, Mar 28, 2019 at 12:23 PM James Morris <jmorris@xxxxxxxxx> wrote: > > On Thu, 28 Mar 2019, Matthew Garrett wrote: > > > On Wed, Mar 27, 2019 at 8:15 PM James Morris <jmorris@xxxxxxxxx> wrote: > > > OTOH, this seems like a combination of mechanism and policy. The 3 modes > > > are a help here, but I wonder if they may be too coarse grained still, > > > e.g. if someone wants to allow a specific mechanism according to their own > > > threat model and mitigations. > > > > In general the interfaces blocked by these patches could also be > > blocked with an LSM, and I'd guess that people with more fine-grained > > requirements would probably take that approach. > > So... I have to ask, why not use LSM for this in the first place? > > Either with an existing module or perhaps a lockdown LSM? Some of it isn't really achievable that way - for instance, enforcing module or kexec signatures. We have other mechanisms that can be used to enable that which could be done at the more fine-grained level, but a design goal was to make it possible to automatically enable a full set of integrity protections under specified circumstances.
