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[Pavel Rojtberg <pavel@xxxxxxxxxxxx>]

1. asks for a password
2. Setting SB State Failed
3. nothing says I should reboot
4. upon reboot configuration screen pops up and asks random characters from the password entered before
5. allows me to disable verification

in case the above is the correct user story, I have the following
remark:

this seems to disable all verification after shim. Before the change the kernel was still verified and only the the modules were not.
Therefore I would say things were more secure before.

Is it possible to just disable signed module enforcement again?

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https://bugs.launchpad.net/bugs/1571691

Title:
  linux: MokSBState is ignored

Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Xenial:
  Fix Released

Bug description:
  Ubuntu-4.4.0-20.36 was released with signed module enforcement
  enabled, but contained no way of disabling secure boot for DKMS.
  Without these kernel patches it is possible to get your machine in an
  unbootable state, especially if you don't have a fallback kernel.

  This patch set implements the ability to disable secure boot on demand
  from user space (with some password shennaigans). If one boots in
  secure boot mode and then installs a third party module (such as
  DKMS), then a dialog is displayed giving the user an option to disable
  secure boot, thereby also disabling module signature verification.
  Patch 1/2 is a scaffold patch of which only the GUID macros are
  actually used. The rest of the code is fenced by
  CONFIG_MODULE_SIG_UEFI which will not be enabled until a later series.
  Patch 2/2 is where MOKSBState is read and implemented. Patch 3/3
  simply prints a bit more informative state information.

  Information regarding secure boot and signed module enforcement will
  appear in the kernel log thusly:

  'Secure boot enabled' - normal secure boot operation with signed module enforcement.
  'Secure boot MOKSBState disabled' - UEFI Secure boot state has been over-ridden by MOKSBState. No signed module enforcement.

  In the absense of a 'Secure boot' string assume that secure boot is
  disabled or does not exist.

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