Linux users may face yet another hurdle related to Secure Boot when the Microsoft-signed key used by many distributions to support the firmware-based security feature expires on September 11, leaving users at the mercy of distribution from OEMs, and systems possibly not receiving a necessary firmware update.
As LWN reported (paywall) that Microsoft will stop using the expiring key to sign the shim in September. “But the replacement key, which has been available since 2023, may not be installed on many systems; worse yet, it may require the hardware vendor to issue an update for the system firmware, which may or may not happen,” LWN said. “It seems that the vast majority of systems will not be lost in the shuffle, but it may require extra work from distributors and users.”
The report said manufacturers could add support for the new key in a full firmware update or by updating the KEK database. The former assumes that manufacturers would be interested in distributing a firmware update for a wide variety of products so a small percentage of their users could use Secure Boot with a non-Windows OS; the latter is an unproven mechanism that isn’t guaranteed to work on all devices. Both seem likely to leave at least some people to figure out a solution on their own.
If you start with a reasonably recent Windows machine, there’s a TPM with secure boot (and MS keys) enabled. If setting up dualboot Windows/Linux, you’re going through BIOS/UEFI, so expiring keys will affect you. Booting into Windows and doing an update should fix the problem.
If you disabled secureboot/FDE, then installed Linux and left it at that, you should be OK.
But under Linux, those who reenable fulldisk encryption or secure boot via the TPM may be impacted by this, and since they’ve removed Windows, they may be screwed: https://allthings.how/how-to-enable-tpm-encryption-and-secure-boot-on-ubuntu-24-04/
So why can’t Linux just do whatever the Windows update does?
Tools to do that exists.
fwupdis a tool to update firmwares. I just tested it on a thinkpad and went from 351 keys to 518 secureboot keys.GNOME Software also uses fwupd, that should take care of a good chunk of users.
So this is an exaggerated non-issue that is phrased as if it was the end of Linux? Crazy, this never happened before! See you all next week when Linux is doomed again.
Its an exaggerated
non-issueLinux is not a uniform userbase. Many systems will be affected by this. Many users will be fine because they use a well used and maintained distro. Many servers and embedded systems will not be fine.
That raspi running your pihole that is never updated? Yeah that might just stop booting next time there is a poweroutage and you wouldn’t know what’s up.
I don’t understand, a. Why is Linux using Microsoft keys?, and b. Why isn’t this a problem for Windows too?
From https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/8/html/managing_monitoring_and_updating_the_kernel/signing-a-kernel-and-modules-for-secure-boot_managing-monitoring-and-updating-the-kernel: “In addition, the signed first-stage boot loader and the signed kernel include embedded Red Hat public keys. These signed executable binaries and embedded keys enable RHEL 8 to install, boot, and run with the Microsoft UEFI Secure Boot Certification Authority keys. These keys are provided by the UEFI firmware on systems that support UEFI Secure Boot.”
Basically the Microsoft keys are ones that the firmware vendor (motherboard or chip manufacturer) recognizes as secure by default (via CA validation). You can override them. It’s not a Linux issue but a hardware-vendor-defaulting-to-Microsoft issue.
Another way that secure boot is snake oil, useless, locked in bullshit.
Works fine for me and the billions of business using it 🤷♂️
Same thing for all the trusted certs at the os level.
Wow, billions of business. 🙄
You’re an idiot if you think you’re privacy would be better off without trusted root certs and businesss taking liability around protecting them 🤷♂️
