[Bug 1845289] Re: Grub EFI amd64 no longer start EFI/Microsoft/Boot/bootmgfw.efi

[Mathieu Trudel-Lapierre]

It has nothing to do with whether the file handle is closed or not; this
is just confusing code because of how it's built.

Shim is supposed to be installed by the installer when you set up the
system in UEFI mode; this is done for you by the installer, and isn't a
dependency of grub because grub does not require shim to work; but
things *will* work better with shim installed. So, I strongly recommend
anyone running into such issues make sure it is installed on their
system, as it is supposed to be.

Now, after tracing more of the code, it looks like the issue is that
grub_load_and_start_image() is insufficient to complete the boot process
in handle_image()... You get the image loaded, but StartImage is never
called, which would explain why you're seeing things go back to the
menu.

Now, I don't think it's worth digging more into this code path, since if
SB is disabled then shim_verify should be letting images work,
unvalidated but accepted; so it would otherwise not get run. I'll go
ahead and drop the extra check for SB state in
linuxefi_secure_validate().

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to grub2 in Ubuntu.
https://bugs.launchpad.net/bugs/1845289

Title:
  Grub EFI amd64 no longer start EFI/Microsoft/Boot/bootmgfw.efi

Status in grub2 package in Ubuntu:
  In Progress
Status in grub2 source package in Eoan:
  Triaged

Bug description:
  [Impact]
  Dual-boot users who have somehow had shim uninstalled from their system / Secure Boot disabled.

  [Test case]
  (system with dual-boot setup for Ubuntu and Windows)
  1) uninstall shim/shim-signed from the system
  2) Run 'sudo grub-install -v'; ensure grubx64.efi is installed as the ubuntu bootentry (check 'sudo efibootmgr -v')
  3) Reboot.
  4) In system firmware, ensure Secure Boot is disabled.
  5) Attempt to start Windows from the Grub menu.

  Verify that Windows is chainloaded from Grub successfully; without
  returning to the GRUB menu or restarting the whole system.

  [Regression potential]
  Minimal; this is returning the state of the code paths for linuxefi validation back to how they were in GRUB 2.02; the extra check for the Secure Boot state is unnecessary at that point since it will be run again later when validating the images. This affects all validation code paths on UEFI but the net effect of reverting that change should be nil due to the duplication of code that already exists.

  ---

  On a dual boot computer with Windows 10 Pro and Ubuntu 19.10, since a
  month, Grub was unable to boot Windows 10. Hitting the Windows entry
  line give me a 0.1s black screen and get me back to Grub Menu.

  sudo update-grub give me :

  Sourcing file `/etc/default/grub'
  Sourcing file `/etc/default/grub.d/init-select.cfg'
  Generating grub configuration file ...
  Found linux image: /boot/vmlinuz-5.3.0-10-generic
  Found initrd image: /boot/initrd.img-5.3.0-10-generic
  Found Windows Boot Manager on /dev/sda1@/EFI/Microsoft/Boot/bootmgfw.efi
  Adding boot menu entry for EFI firmware configuration
  done

  ProblemType: Bug
  DistroRelease: Ubuntu 19.10
  Package: grub-efi-amd64 2.04-1ubuntu5
  ProcVersionSignature: Ubuntu 5.3.0-10.11-generic 5.3.0-rc8
  Uname: Linux 5.3.0-10-generic x86_64
  ApportVersion: 2.20.11-0ubuntu7
  Architecture: amd64
  CurrentDesktop: ubuntu:GNOME
  Date: Wed Sep 25 08:01:05 2019
  ProcEnviron:
   TERM=xterm-256color
   PATH=(custom, no user)
   XDG_RUNTIME_DIR=<set>
   LANG=fr_FR.UTF-8
   SHELL=/bin/bash
  SourcePackage: grub2
  UpgradeStatus: Upgraded to eoan on 2018-11-14 (314 days ago)

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1845289/+subscriptions