Windows update gives error in dual boot

In recent years, many users prefer to use a dual boot system to enjoy both Windows and a Linux distribution of their choice on their computers.

This coexistence between the operating systems has been mostly peaceful. But a recent update from Microsoft has caused unexpected chaos, leaving many users unable to boot Linux on their dual boot devices.

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The cause of the problem on dual boot devices

On Tuesday, several users began reporting problems when trying to boot Linux on their dual-boot systems. Instead of loading normally, the devices displayed a cryptic message that included the phrase: “Something went very wrong.”

This error ended up leaving many without access to the system, generating a wave of complaints and requests for help on support forums.

PLEASE HELP Error message: Verifying shim SBAT data failed: Security policy violation Something went seriously wrong: SBAT self-test failed: Security Policy Violation
byu/paku1234 inlinuxquestions

The cause of this problem was an update released by Microsoft as part of its monthly patch release. This update was intended to fix a two-year-old vulnerability in GRUB, the boot manager widely used by Linux distributions.

The vulnerability, identified as CVE-2022-2601, allowed hackers to bypass Secure Boot, an important security feature for ensuring that software running at boot time is legitimate.

Although the vulnerability was discovered in 2022, Microsoft only released the fix now. Unfortunately, this fix has had unforeseen consequences. Upon installing the update, devices configured to dual boot between Windows and Linux were unable to boot Linux.

When users tried to load the system, they were greeted with the error message: “SBAT shim data verification failed: security policy violation. Something went terribly wrong: SBAT self-verification failed: security policy violation.”

The impact on the Linux community

Immediately after the update was released, discussion and support forums were flooded with reports of the issue. Popular distributions such as Debian, Ubuntu, Mint, Zorin OS, Puppy Linux, and more were affected. The bug left users frustrated, especially those who rely on dual boot for their work or studies.

So far, Microsoft has not publicly acknowledged the bug or explained why it was not detected during testing. In the official bulletin for CVE-2022-2601, the company had explained that the update would install an SBAT (a Linux mechanism for revoking various components during boot), but that this would only occur on devices configured to run only Windows.

Microsoft assured that dual-boot systems would not be affected, although it did warn that older versions of Linux could experience issues. But that’s not exactly what happened.

That’s because the update was applied to devices running both Windows and Linux, including not only dual-boot systems, but also Windows devices that can boot Linux from an ISO, USB thumb drive, or optical media. Additionally, many of the affected systems were running recently released versions of Linux, which contradicts Microsoft’s prediction that only older versions would be impacted.

Fonte: pplware