For guests that do not make use of the EBC feature the boot should not
be impacted by this module. This requires removing the boot.mount unit
because it will unconditionally create a dependency on a unit that
conflicts with that idea. The downside is that mounting of the boot
partition has to be done manually.
Fixes: https://github.com/ibm-s390-linux/s390-tools/issues/202
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Finn Callies <fcallies@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Include the required kernel modules unconditionally when this module is
installed into an initramfs.
The new .conf file contains a list of kernel modules that are loaded by
the systemd-modules-load.service systemd unit.
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Finn Callies <fcallies@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Add 95ibm-sel-ebc dracut module for secure boot-time customization of
SEL guests.
Introduce the IBM SEL EBC dracut module (95ibm-sel-ebc) that enables
Early Boot Customization for SEL guests during the initramfs phase.
The module implements a critical security architecture to prevent
injection attacks: all EBC resources (.asr and .pol files) are copied from
/boot/sics (which resides in the qcow2 image on the host filesystem) to
/run/ibm-sel-ebc (a tmpfs/RAM-backed directory). Since guest RAM is
protected by the Ultravisor, this prevents malicious hosts from modifying
EBC resources during boot.
Systemd units and their purposes:
- ibm-sel-ebc.target: Groups all EBC-related units
- boot.mount: Mounts /dev/disk/by-label/boot to /boot
- ibm-sel-ebc-ensure-sics.service: Fallback to create /boot/sics/ if boot
partition mount fails (supports Kata VM scenarios)
- ibm-sel-ebc-pvebc.service: Main unit that copies EBC resources to RAM,
invokes pvebc tool to verify integrity and add ASRs to UV, retrieves
LUKS passphrase from UV secret store
- ibm-sel-ebc-override-crypttab.service: Replaces /etc/crypttab with
prepared IBM SEL EBC crypttab, reloads systemd daemon, starts cryptsetup
service
- ibm-sel-ebc-paes-enforce.service: Verifies root filesystem uses PAES
encryption to prevent root filesystem substitution attacks
All units write logs to /boot/sics/log for debugging, accessible even if
root filesystem fails to mount. Units are triggered by rd.ibm-sel-ebc
kernel parameter and only execute in initramfs
(ConditionPathExists=/etc/initrd-release).
Assisted-by: IBM Bob:1.0.1
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Finn Callies <fcallies@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
