Re: [PATCH 1/3] integrity: Make arch_ima_get_secureboot integrity-wide

[Mimi Zohar <zohar@linux.ibm.com>]

On Fri, 2026-01-16 at 10:41 +0100, Ard Biesheuvel wrote:
> On Thu, 15 Jan 2026 at 01:43, Coiby Xu <coxu@redhat.com> wrote:
> > 
> > EVM and other LSMs need the ability to query the secure boot status of
> > the system, without directly calling the IMA arch_ima_get_secureboot
> > function. Refactor the secure boot status check into a general,
> > integrity-wide function named arch_integrity_get_secureboot.
> > 
> > Define a new Kconfig option CONFIG_INTEGRITY_SECURE_BOOT, which is
> > automatically configured by the supported architectures. The existing
> > IMA_SECURE_AND_OR_TRUSTED_BOOT Kconfig loads the architecture specific
> > IMA policy based on the refactored secure boot status code.
> > 
> > Reported-and-suggested-by: Mimi Zohar <zohar@linux.ibm.com>
> > Suggested-by: Roberto Sassu <roberto.sassu@huaweicloud.com>
> > Signed-off-by: Coiby Xu <coxu@redhat.com>
> > ---
> >  arch/arm64/Kconfig                            |  1 +
> >  arch/powerpc/Kconfig                          |  1 +
> >  arch/powerpc/kernel/Makefile                  |  2 +-
> >  arch/powerpc/kernel/ima_arch.c                |  5 --
> >  arch/powerpc/kernel/integrity_sb_arch.c       | 13 +++++
> >  arch/s390/Kconfig                             |  1 +
> >  arch/s390/kernel/Makefile                     |  1 +
> >  arch/s390/kernel/ima_arch.c                   |  6 --
> >  arch/s390/kernel/integrity_sb_arch.c          |  9 +++
> >  arch/x86/Kconfig                              |  1 +
> >  arch/x86/include/asm/efi.h                    |  4 +-
> >  arch/x86/platform/efi/efi.c                   |  2 +-
> >  include/linux/ima.h                           |  7 +--
> >  include/linux/integrity.h                     |  8 +++
> >  security/integrity/Kconfig                    |  6 ++
> >  security/integrity/Makefile                   |  3 +
> >  security/integrity/efi_secureboot.c           | 56 +++++++++++++++++++
> >  security/integrity/ima/ima_appraise.c         |  2 +-
> >  security/integrity/ima/ima_efi.c              | 47 +---------------
> >  security/integrity/ima/ima_main.c             |  4 +-
> >  security/integrity/platform_certs/load_uefi.c |  2 +-
> >  21 files changed, 111 insertions(+), 70 deletions(-)
> >  create mode 100644 arch/powerpc/kernel/integrity_sb_arch.c
> >  create mode 100644 arch/s390/kernel/integrity_sb_arch.c
> >  create mode 100644 security/integrity/efi_secureboot.c
> > 
> > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> > index 93173f0a09c7..4c265b7386bb 100644
> > --- a/arch/arm64/Kconfig
> > +++ b/arch/arm64/Kconfig
> > @@ -2427,6 +2427,7 @@ config EFI
> >         select EFI_STUB
> >         select EFI_GENERIC_STUB
> >         imply IMA_SECURE_AND_OR_TRUSTED_BOOT
> > +       imply INTEGRITY_SECURE_BOOT
> 
> This allows both to be en/disabled individually, which I don't think
> is what we want. It also results in more churn across the
> arch-specific Kconfigs than needed.
> 
> Wouldn't it be better if IMA_SECURE_AND_OR_TRUSTED_BOOT 'select'ed
> INTEGRITY_SECURE_BOOT in its Kconfig definition?

As much as possible, EVM (and other LSMs) shouldn't be dependent on another LSM,
in this case IMA, being configured.