From: KP Singh <kpsingh@kernel.org>
To: linux-security-module@vger.kernel.org, bpf@vger.kernel.org
Cc: ast@kernel.org, daniel@iogearbox.net, memxor@gmail.com,
James.Bottomley@HansenPartnership.com, paul@paul-moore.com,
KP Singh <kpsingh@kernel.org>
Subject: [PATCH bpf-next 10/13] bpf: invoke security_bpf_prog_load_post_integrity from the metadata kfunc
Date: Fri, 22 May 2026 04:32:30 +0200 [thread overview]
Message-ID: <20260522023234.3778588-11-kpsingh@kernel.org> (raw)
In-Reply-To: <20260522023234.3778588-1-kpsingh@kernel.org>
Call security_bpf_prog_load_post_integrity from
bpf_loader_verify_metadata just before promoting
prog->aux->sig.verdict from BPF_SIG_OK to BPF_SIG_METADATA_VERIFIED.
This lets policy LSMs deny the metadata-verified transition.
A non-zero return aborts the kfunc and leaves the verdict at
BPF_SIG_OK; observers that key off METADATA_VERIFIED never see a
verdict the LSM denied.
Signed-off-by: KP Singh <kpsingh@kernel.org>
---
kernel/bpf/helpers.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 9afa71fbcac3..52e71fb6e200 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -4300,6 +4300,14 @@ __bpf_kfunc int bpf_loader_verify_metadata(struct bpf_map *map,
if (memcmp(sha, hash, SHA256_DIGEST_SIZE))
return -EBADMSG;
+ /* Metadata integrity is decided by the checks above; the LSM hook
+ * is an observer of that verdict and may apply policy (e.g. deny),
+ * but cannot vouch for integrity it did not verify itself.
+ */
+ err = security_bpf_prog_load_post_integrity(aux__ign->prog);
+ if (err)
+ return err;
+
aux__ign->sig.verdict = BPF_SIG_METADATA_VERIFIED;
return 0;
}
--
2.53.0
next prev parent reply other threads:[~2026-05-22 2:32 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-22 2:32 [PATCH bpf-next 00/13] Signed BPF + IPE Policies KP Singh
2026-05-22 2:32 ` [PATCH bpf-next 01/13] bpf: expose signature verdict to LSMs via bpf_prog_aux KP Singh
2026-05-22 2:32 ` [PATCH bpf-next 02/13] bpf: include prog BTF in the signed loader signature scope KP Singh
2026-05-22 2:32 ` [PATCH bpf-next 03/13] bpf, libbpf: load prog BTF in the skel_internal loader KP Singh
2026-05-22 2:32 ` [PATCH bpf-next 04/13] bpf: add bpf_loader_verify_metadata kfunc KP Singh
2026-05-22 2:32 ` [PATCH bpf-next 05/13] bpf: compute prog->digest at BPF_PROG_LOAD entry KP Singh
2026-05-22 2:32 ` [PATCH bpf-next 06/13] bpf: resolve loader-style kfunc CALLs against prog BTF KP Singh
2026-05-22 2:32 ` [PATCH bpf-next 07/13] libbpf: generate prog BTF for loader programs KP Singh
2026-05-22 2:32 ` [PATCH bpf-next 08/13] bpftool gen: embed loader prog BTF in the lskel header KP Singh
2026-05-22 2:32 ` [PATCH bpf-next 09/13] lsm: add bpf_prog_load_post_integrity hook KP Singh
2026-05-22 2:32 ` KP Singh [this message]
2026-05-22 2:32 ` [PATCH bpf-next 11/13] ipe: add BPF program signature properties KP Singh
2026-05-22 2:32 ` [PATCH bpf-next 12/13] ipe: gate post-integrity BPF program loads KP Singh
2026-05-22 2:32 ` [PATCH bpf-next 13/13] selftests/bpf: add IPE BPF policy integration tests KP Singh
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