[Bug 2107457] Re: Can't boot after installation with TPM backed FDE on xps9320

[Chris Coulson]

I've just figured out what the issue is here - this device has a
debugging endpoint built into the firmware which is indicated in PCR7

7    a62bd67b2cc295976651b354468c0047f8d1547d25056ded5952aaf5991762a3
EV_EFI_ACTION  UEFI Debug Mode

This causes us to silently mis-predict the PCR7 value today. This will
eventually be detected here and will prevent FDE from being enabled:

https://github.com/canonical/secboot/blob/2972449df0baab78eee8f5d99e01d479673651b0/efi/preinstall/check_host_security.go#L67

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to subiquity in Ubuntu.
https://bugs.launchpad.net/bugs/2107457

Title:
  Can't boot after installation with TPM backed FDE on xps9320

Status in subiquity package in Ubuntu:
  New

Bug description:
  I tried installing Ubuntu 25.04 desktop with TPM backed FDE on two
  different XPS 9320 units.

  The installation seems to succeed.

  However, on first boot, it is asking me for a recovery key.

  Please enter the recovery key for volume ubuntu-
  data-a2b3ba2e-2555-4957-a47b-94804d4c119 for device /dev/disk/by-
  uuid/6bdc5a11-5d7d-4d64-89f-05d9464191e (press TAB for no echo)

  Inputting the passphrase entered during the installation does not work

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/subiquity/+bug/2107457/+subscriptions