[PATCH v2] integrity: Extract secure boot enquiry function out of IMA

[GONG Ruiqi]

On 7/8/2025 4:35 AM, Nayna Jain wrote:
> 
> On 7/2/25 10:07 PM, GONG Ruiqi wrote:
>> 
>> ...
>>
>> "We encountered a boot failure issue in an in-house testing, where the
>> kernel refused to load its modules since it couldn't verify their
>> signature. The root cause turned out to be the early return of
>> load_uefi_certs(), where arch_ima_get_secureboot() returned false
>> unconditionally due to CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT=n, even
>> though the secure boot was enabled.
> Thanks for sharing additional details.
> 
> From x86 Kconfig:
> 
> /For config x86:
> 
>     imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
> /
> And IMA_SECURE_AND_OR_TRUSTED_BOOT is dependent on IMA_ARCH_POLICY .
> 
> And from Linux Kernel Kbuild documentation( https://docs.kernel.org/
> kbuild/kconfig-language.html) :
> 
> /weak reverse dependencies: “imply” <symbol> [“if” <expr>]
> 
> This is similar to “select” as it enforces a lower limit on another
> symbol except that the “implied” symbol’s value may still be set to n
> from a direct dependency or with a visible prompt.
> 
> /Following the example from the documentation, if  it is EFI enabled and
> IMA_ARCH_POLICY is set to y then this config should be default enabled.
> 
> If it is EFI enabled and IMA_ARCH_POLICY is set to N, then the setting
> for IMA_SECURE_AND_OR_TRUSTED_BOOT should be prompted during the build.
> The default setting for prompt is N. So, the person doing the build
> should actually select Y to enable IMA_ARCH_POLICY.
> 
> Wondering what is the scenario for you? Unless you have IMA_ARCH_POLICY
> set to N, this config should have been ideally enabled. If you have
> explicitly set it to N, am curious any specific reason for that.

Hi Nayna. Sorry for the late reply. Super busy these days...

Yes, IMA_ARCH_POLICY was not set. The testing was conducted on
openEuler[1], a Linux distro mainly for arm64 & x86, and the kernel was
compiled based on its own openeuler_defconfig[2], which set
IMA_ARCH_POLICY to N.

-Ruiqi

[1]: https://www.openeuler.org/en/
[2]:
https://gitee.com/openeuler/kernel/blob/OLK-6.6/arch/arm64/configs/openeuler_defconfig


> 
> Thanks & Regards,
> 
>    - Nayna
>>
>> ...