On Wed, Apr 04, 2018 at 03:02:33PM +0200, Greg Kroah-Hartman wrote: > On Wed, Apr 04, 2018 at 08:57:43AM -0400, Theodore Y. Ts'o wrote: > > On Wed, Apr 04, 2018 at 04:30:18AM +0000, Matthew Garrett wrote: > > > What I'm afraid of is this turning into a "security" feature that ends up > > > being circumvented in most scenarios where it's currently deployed - eg, > > > module signatures are mostly worthless in the non-lockdown case because you > > > can just grab the sig_enforce symbol address and then kexec a preamble that > > > flips it back to N regardless of the kernel config. > > > > Whoa. Why doesn't lockdown prevent kexec? Put another away, why > > isn't this a problem for people who are fearful that Linux could be > > used as part of a Windows boot virus in a Secure UEFI context? > > Because no one is afraid of that :) Well, this is the excuse used by Windows. Some more cynical people believe it's really an anti-competitvie thing, but we should acknowledge this is what is causing the fear that some distros have that their UEFI secure boot certs will be revoked by Microsoft if they don't have this crazy lockdown enforcement for UEFI Secure Boot. So how about this as a compromise. We can have a config option for the behavior that those distros (and Matthew) want, and we can have separate config options that turn things on in what others would say is a more rational way. And I would all be for having the Kconfig description says, "This config option is only needed by distros who are fearful of Microsoft revoking their UEFI secure boot certificate." - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
