Re: [PATCH v4 10/10] ipe: Add BPF program load policy enforcement via Hornet integration

Fan Wu
2026-04-16T21:04:03Z

On Thu, Apr 16, 2026 at 10:35 AM Blaise Boscaccy
<bboscaccy@linux.microsoft.com> wrote:
>
> Add support for the bpf_prog_load_post_integrity LSM hook, enabling IPE
> to make policy decisions about BPF program loading based on integrity
> verdicts provided by the Hornet LSM.
>
> New policy operation:
> op=BPF_PROG_LOAD - Matches BPF program load events
>
> New policy properties:
> bpf_signature=NONE - No Verdict
> bpf_signature=OK - Program signature and map hashes verified
> bpf_signature=UNSIGNED - No signature provided
> bpf_signature=PARTIALSIG - Signature OK but no map hash data
> bpf_signature=UNKNOWNKEY - Cert not trusted
> bpf_signature=UNEXPECTED - An unexpected hash value was encountered
> bpf_signature=FAULT - System error during verification
> bpf_signature=BADSIG - Signature or map hash verification failed
> bpf_keyring=BUILTIN - Program was signed using a builtin keyring
> bpf_keyring=SECONDARY - Program was signed using the secondary keyring
> bpf_keyring=PLATFORM - Program was signed using the platform keyring
> bpf_kernel=TRUE - Program originated from kernelspace
> bpf_kernel=FALSE - Program originated from userspace
>
> These properties map directly to the lsm_integrity_verdict enum values
> provided by the Hornet LSM through security_bpf_prog_load_post_integrity.
>
> The feature is gated on CONFIG_IPE_PROP_BPF_SIGNATURE which depends on
> CONFIG_SECURITY_HORNET.
>
> Example policy for bpf signature enforcement:
> DEFAULT op=BPF_PROG_LOAD action=DENY
> op=BPF_PROG_LOAD is_kernel=TRUE action=ALLOW
> op=BPF_PROG_LOAD bpf_signature=OK action=ALLOW
>
> Signed-off-by: Blaise Boscaccy <bboscaccy@linux.microsoft.com>

Hi Blaise,

I have not finished reviewing the code yet, so I do not have
implementation comments at this point.

Since this code introduces new policy semantics, it would be helpful
to also reflect that in the IPE documentation, and perhaps include a
link to the Hornet documentation for context.

-Fan