On Wed, Oct 25, 2017 at 01:22:21PM -0700, Jerry Snitselaar wrote: > On Wed Oct 25 17, Jarkko Sakkinen wrote: > > On Wed, Oct 25, 2017 at 07:17:17AM -0700, Matthew Garrett wrote: > > > On Wed, Oct 25, 2017 at 6:44 AM, Jarkko Sakkinen > > > <jarkko.sakkinen@xxxxxxxxxxxxxxx> wrote: > > > > I'm implementing a fix for CVE-2017-15361 that simply blacklists > > > > vulnerable FW versions. I think this is the only responsible action from > > > > my side that I can do. > > > > > > I'm not sure this is ideal - do Infineon have any Linux tooling for > > > performing firmware updates, and if so will that continue working if > > > the device is blacklisted? It's also a poor user experience to have > > > systems using TPM-backed disk encryption keys suddenly rendered > > > unbootable, and making it as easy as possible for people to do an > > > upgrade and then re-seal secrets with new keys feels like the correct > > > approach. > > > > I talked today with Alexander Steffen in the KS unconference and we > > concluded that this would be a terrible idea. > > > > Alexander stated the following things about FW updates (Alexander, > > please correct me if I state something incorrectly or if you have > > something to add): > > > > * FW update can be constructed either in a way that the keys in the > > NVRAM are not cleared or in a way that they are cleared. > > * FW update cannot be directly applied to the TPM but must come as > > part of the firmware update from the vendor. > > If that is the case, can the two of you get Intel to update the fw > for the tpm in the nuc5i5myhe (slb9665) :) ? It has needed an update for a while, due > to issues with context management. My understanding (quite likely I misunderstood) > from a recent discussion with Peter was that it was possible to update the fw. I don't know but I can at least forward the complains to the mother ship :-) It is fairly intuitive why dTPM cannot be updated without full firmware update. It's part of the proprietary HW platform, not something connected through PCI, USB or any standard bus. /Jarkko
