Public bug reported:
[Impact]
Compressed kernels as we have on arm64 cause grub to fail in two ways:
1. In all versions, grub-check-signatures will fail to verify the
binaries using sbverify, complain about that in debconf, and then abort
the installation/upgrade of grub-efi-arm64-signed
2. In 2.06, the verifiers framework runs before any decompression,
causing the kernels to fail verification, as it tries to verify the
compressed data. In grub 2.04, we manually verified the file after we
had opened it (hence after all filters).
[Attack plan]
1. Modify grub-check-signatures to optionally decompress kernels before passing
them to sbverify
2. Modify grub to either
a) verify after decompress
b) disable shim_lock verifier on arm64, and only use the rhboot
We do not know if this is a long-term solution, we really should migrate
back to kernels that are proper EFI executables themselves such that we
can use standard EFI functions to run them as well.
[Test plan]
TBD
[Where problems could occur]
TBD
** Affects: grub2-unsigned (Ubuntu)
Importance: Undecided
Status: New
** Tags: regression-proposed
** Also affects: grub2 (Ubuntu)
Importance: Undecided
Status: New
** No longer affects: grub2 (Ubuntu)
** Tags added: regression-proposed
--
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1954683
Title:
grub is missing secure boot support for compressed kernels
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/grub2-unsigned/+bug/1954683/+subscriptions
--
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
