We now have signature check logic in grub which allows us to treat
files differently depending on their file type.
Treat a loaded device tree like an overlayed ACPI table.
Both describe hardware, so I suppose their threat level is the same.
Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
This module provides shim lock verification for various kernels
if UEFI secure boot is enabled on a machine.
It is recommended to put this module into GRUB2 standalone image
(avoid putting iorw and memrw modules into it; they are disallowed
if UEFI secure boot is enabled). However, it is also possible to use
it as a normal module. Though such configurations are more fragile
and less secure due to various limitations.
If the module is loaded and UEFI secure boot is enabled then:
- module itself cannot be unloaded (persistent module),
- the iorw and memrw modules cannot be loaded,
- if the iorw and memrw modules are loaded then
machine boot is disabled,
- GRUB2 defers modules and ACPI tables verification to
other verifiers.
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
