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New Secure Boot Patches Break Hibernation
hypnosec writes "Matthew Garrett published some patches today which break hibernate and kexec support on Linux when Secure Boot is used. The reason for disabling hibernation is that currently the Linux kernel doesn't have the capability of verifying the resume image when returning from hibernation, which compromises the Secure Boot trust model. The reason for disabling the kexec support while running in Secure Boot is that the kernel execution mechanism may be used to load a modified kernel thus bypassing the trust model of Secure Boot."
Before arming your tactical nuclear flame cannon, note that mjg says "These patches break functionality that people rely on without providing any functional equivalent, so I'm not suggesting that they be merged as-is." Support for signed kexec should come eventually, but it looks like hibernation will require some clever hacking to support properly in a Restricted Boot environment.
It's my goddamn computer, my goddamn hardware, and it's MINE. I will run any fucking operating system I goddamn well please on it, and if Microsoft doesn't like that, they can FUCK THEMSELVES right in the GODDAMN EAR.
The kernel can execute ring 0 instructions. Your initrd can't. The difference is that you could construct an appropriately modified hibernation image that booted an arbitrary kernel - or even an entirely separate OS. In that scenario, your kernel is effectively a new bootloader, except unlike the signed bootloaders it'll happily boot an entirely unsigned OS. That's unlikely to end well.
But, conceptually, you're right. Secure Boot doesn't magically make a system secure, but it *is* a vital part of system security - if you can't trust your kernel, any other security you attempt to build is pretty much pointless.
"DRM is to promote sales through reducing piracy "
No, the point of DRM is to increase profits by removing a potential threat to sales. The point of secure boot is potentially lock hardware to the operating system. The chain of proof is just a selling tactic at best but irrelevant as there are a myriad of ways to compromise a system for those with the will to do so. It's more effective as a wedge to eventually control hardware manufacture. Remember this kind of behavior wouldn't be new for Microsoft.