[PATCH v4 00/10] Reintroduce Hornet LSM

[PATCH v4 00/10] Reintroduce Hornet LSM

[Blaise Boscaccy]

This patch series introduces the next iteration of the Hornet LSM.
Hornet’s goal is to provide a secure and extensible in-kernel
signature verification mechanism for eBPF programs.

Hornet addresses concerns from users who require strict audit trails and
verification guarantees for eBPF programs, especially in
security-sensitive environments. Many production systems need assurance
that only authorized, unmodified eBPF programs are loaded into the
kernel. Hornet provides this assurance through cryptographic signature
verification.

The currently accepted loader-plus-map signature verification scheme,
mandated by Alexei and KP, is simple to implement and generally
acceptable if users and administrators are satisfied with it. However,
verifying both the loader and the maps offers additional benefits
beyond verifying the loader alone:

1. Security and Audit Integrity

A key advantage is that the LSM hook for authorizing BPF program loads
can operate after signature verification. This ensures:

* Access control decisions are based on verified signature status.
* Accurate system state measurement and logging.
* Log entries claiming a verified signature are truthful, avoiding
  misleading records where only the loader was verified while the actual
  BPF program verification occurs later without logging.

2. TOCTOU Attack Prevention

The current map hash implementation may be vulnerable to a TOCTOU
attack because it allows unfrozen maps to cache a previously
calculated hash. The accepted “trusted loader” scheme cannot detect
this and may permit loading altered maps.

3. Supply Chain Integrity

Verify that eBPF programs and their associated map data have not been
modified since they were built and signed, in the kernel proper, may
aid in protecting against supply chain attacks.

This approach addresses concerns from users who require strict audit
trails and verification guarantees, especially in security-sensitive
environments. Map hashes for extended verification are passed via the
existing PKCS#7 UAPI and verified by the crypto subsystem. Hornet then
calculates the program’s verification state.  Hornet itself does not
enforce a policy on whether unsigned or partially signed programs
should be rejected. It delegates that decision to downstream LSMs
hook, making it a composable building block in a larger security
architecture.

Changes in V4:
- IPE integration
- Arbitrary keyring support

Link to V3: https://lore.kernel.org/linux-security-module/20260326060655.2550595-1-bboscaccy@linux.microsoft.com/

Changes in V3:
- Updated for signed attribute patch series changes
- Added some new result enum values
- Minor documentation clarification
- Misc style fixes
- Added missing signed-off-by tags

Link to V2: https://lore.kernel.org/linux-security-module/20260227233930.2418522-1-bboscaccy@linux.microsoft.com/

Changes in V2:
- Addressed possible TocTou races in hash verification
- Improved documentation and tooling
- Added Alexie's nack

Link to RFC: https://lore.kernel.org/linux-security-module/20251211021257.1208712-1-bboscaccy@linux.microsoft.com/


Blaise Boscaccy (6):
  lsm: security: Add additional enum values for bpf integrity checks
  security: Hornet LSM
  hornet: Introduce gen_sig
  hornet: Add a light skeleton data extractor scripts
  selftests/hornet: Add a selftest for the Hornet LSM
  ipe: Add BPF program load policy enforcement via Hornet integration

James Bottomley (3):
  crypto: pkcs7: add flag for validated trust on a signed info block
  crypto: pkcs7: add ability to extract signed attributes by OID
  crypto: pkcs7: add tests for pkcs7_get_authattr

Paul Moore (1):
  lsm: framework for BPF integrity verification

 Documentation/admin-guide/LSM/Hornet.rst     | 321 +++++++++++++++
 Documentation/admin-guide/LSM/index.rst      |   1 +
 MAINTAINERS                                  |   9 +
 certs/system_keyring.c                       |   1 +
 crypto/asymmetric_keys/Makefile              |   4 +-
 crypto/asymmetric_keys/pkcs7_aa.asn1         |  18 +
 crypto/asymmetric_keys/pkcs7_key_type.c      |  44 ++-
 crypto/asymmetric_keys/pkcs7_parser.c        |  81 ++++
 crypto/asymmetric_keys/pkcs7_parser.h        |   1 +
 crypto/asymmetric_keys/pkcs7_trust.c         |   1 +
 include/crypto/pkcs7.h                       |   4 +
 include/linux/lsm_hook_defs.h                |   5 +
 include/linux/oid_registry.h                 |   3 +
 include/linux/security.h                     |  28 ++
 include/uapi/linux/lsm.h                     |   1 +
 scripts/Makefile                             |   1 +
 scripts/hornet/Makefile                      |   5 +
 scripts/hornet/extract-insn.sh               |  27 ++
 scripts/hornet/extract-map.sh                |  27 ++
 scripts/hornet/extract-skel.sh               |  27 ++
 scripts/hornet/gen_sig.c                     | 392 +++++++++++++++++++
 scripts/hornet/write-sig.sh                  |  27 ++
 security/Kconfig                             |   3 +-
 security/Makefile                            |   1 +
 security/hornet/Kconfig                      |  11 +
 security/hornet/Makefile                     |   7 +
 security/hornet/hornet.asn1                  |  13 +
 security/hornet/hornet_lsm.c                 | 346 ++++++++++++++++
 security/ipe/Kconfig                         |  14 +
 security/ipe/audit.c                         |  15 +
 security/ipe/eval.c                          |  73 +++-
 security/ipe/eval.h                          |   5 +
 security/ipe/hooks.c                         |  37 ++
 security/ipe/hooks.h                         |  11 +
 security/ipe/ipe.c                           |   3 +
 security/ipe/policy.h                        |  14 +
 security/ipe/policy_parser.c                 |  27 ++
 security/security.c                          |  75 +++-
 tools/testing/selftests/Makefile             |   1 +
 tools/testing/selftests/hornet/Makefile      |  63 +++
 tools/testing/selftests/hornet/loader.c      |  21 +
 tools/testing/selftests/hornet/trivial.bpf.c |  33 ++
 42 files changed, 1794 insertions(+), 7 deletions(-)
 create mode 100644 Documentation/admin-guide/LSM/Hornet.rst
 create mode 100644 crypto/asymmetric_keys/pkcs7_aa.asn1
 create mode 100644 scripts/hornet/Makefile
 create mode 100755 scripts/hornet/extract-insn.sh
 create mode 100755 scripts/hornet/extract-map.sh
 create mode 100755 scripts/hornet/extract-skel.sh
 create mode 100644 scripts/hornet/gen_sig.c
 create mode 100755 scripts/hornet/write-sig.sh
 create mode 100644 security/hornet/Kconfig
 create mode 100644 security/hornet/Makefile
 create mode 100644 security/hornet/hornet.asn1
 create mode 100644 security/hornet/hornet_lsm.c
 create mode 100644 tools/testing/selftests/hornet/Makefile
 create mode 100644 tools/testing/selftests/hornet/loader.c
 create mode 100644 tools/testing/selftests/hornet/trivial.bpf.c

-- 
2.53.0

[PATCH v4 01/10] crypto: pkcs7: add flag for validated trust on a signed info block

[Blaise Boscaccy]

From: James Bottomley <James.Bottomley@HansenPartnership.com>

Allow consumers of struct pkcs7_message to tell if any of the sinfo
fields has passed a trust validation.  Note that this does not happen
in parsing, pkcs7_validate_trust() must be explicitly called or called
via validate_pkcs7_trust().  Since the way to get this trusted pkcs7
object is via verify_pkcs7_message_sig, export that so modules can use
it.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Blaise Boscaccy <bboscaccy@linux.microsoft.com>
---
 certs/system_keyring.c                | 1 +
 crypto/asymmetric_keys/pkcs7_parser.h | 1 +
 crypto/asymmetric_keys/pkcs7_trust.c  | 1 +
 3 files changed, 3 insertions(+)

diff --git a/certs/system_keyring.c b/certs/system_keyring.c
index e0761436ec7f4..9bda49295bd02 100644
--- a/certs/system_keyring.c
+++ b/certs/system_keyring.c
@@ -380,6 +380,7 @@ int verify_pkcs7_message_sig(const void *data, size_t len,
 	pr_devel("<==%s() = %d\n", __func__, ret);
 	return ret;
 }
+EXPORT_SYMBOL(verify_pkcs7_message_sig);
 
 /**
  * verify_pkcs7_signature - Verify a PKCS#7-based signature on system data.
diff --git a/crypto/asymmetric_keys/pkcs7_parser.h b/crypto/asymmetric_keys/pkcs7_parser.h
index 6ef9f335bb17f..203062a33def6 100644
--- a/crypto/asymmetric_keys/pkcs7_parser.h
+++ b/crypto/asymmetric_keys/pkcs7_parser.h
@@ -20,6 +20,7 @@ struct pkcs7_signed_info {
 	unsigned	index;
 	bool		unsupported_crypto;	/* T if not usable due to missing crypto */
 	bool		blacklisted;
+	bool		verified; /* T if this signer has validated trust */
 
 	/* Message digest - the digest of the Content Data (or NULL) */
 	const void	*msgdigest;
diff --git a/crypto/asymmetric_keys/pkcs7_trust.c b/crypto/asymmetric_keys/pkcs7_trust.c
index 9a87c34ed1733..78ebfb6373b61 100644
--- a/crypto/asymmetric_keys/pkcs7_trust.c
+++ b/crypto/asymmetric_keys/pkcs7_trust.c
@@ -127,6 +127,7 @@ static int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7,
 		for (p = sinfo->signer; p != x509; p = p->signer)
 			p->verified = true;
 	}
+	sinfo->verified = true;
 	kleave(" = 0");
 	return 0;
 }
-- 
2.53.0

[PATCH v4 02/10] crypto: pkcs7: add ability to extract signed attributes by OID

[Blaise Boscaccy]

From: James Bottomley <James.Bottomley@HansenPartnership.com>

Signers may add any information they like in signed attributes and
sometimes this information turns out to be relevant to specific
signing cases, so add an api pkcs7_get_authattr() to extract the value
of an authenticated attribute by specific OID.  The current
implementation is designed for the single signer use case and simply
terminates the search when it finds the relevant OID.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Blaise Boscaccy <bboscaccy@linux.microsoft.com>
---
 crypto/asymmetric_keys/Makefile       |  4 +-
 crypto/asymmetric_keys/pkcs7_aa.asn1  | 18 ++++++
 crypto/asymmetric_keys/pkcs7_parser.c | 81 +++++++++++++++++++++++++++
 include/crypto/pkcs7.h                |  4 ++
 4 files changed, 106 insertions(+), 1 deletion(-)
 create mode 100644 crypto/asymmetric_keys/pkcs7_aa.asn1

diff --git a/crypto/asymmetric_keys/Makefile b/crypto/asymmetric_keys/Makefile
index bc65d3b98dcbf..f99b7169ae7cd 100644
--- a/crypto/asymmetric_keys/Makefile
+++ b/crypto/asymmetric_keys/Makefile
@@ -53,12 +53,14 @@ clean-files	+= pkcs8.asn1.c pkcs8.asn1.h
 obj-$(CONFIG_PKCS7_MESSAGE_PARSER) += pkcs7_message.o
 pkcs7_message-y := \
 	pkcs7.asn1.o \
+	pkcs7_aa.asn1.o \
 	pkcs7_parser.o \
 	pkcs7_trust.o \
 	pkcs7_verify.o
 
-$(obj)/pkcs7_parser.o: $(obj)/pkcs7.asn1.h
+$(obj)/pkcs7_parser.o: $(obj)/pkcs7.asn1.h $(obj)/pkcs7_aa.asn1.h
 $(obj)/pkcs7.asn1.o: $(obj)/pkcs7.asn1.c $(obj)/pkcs7.asn1.h
+$(obj)/pkcs7_aa.asn1.o: $(obj)/pkcs7_aa.asn1.c $(obj)/pkcs7_aa.asn1.h
 
 #
 # PKCS#7 parser testing key
diff --git a/crypto/asymmetric_keys/pkcs7_aa.asn1 b/crypto/asymmetric_keys/pkcs7_aa.asn1
new file mode 100644
index 0000000000000..7a8857bdf56e1
--- /dev/null
+++ b/crypto/asymmetric_keys/pkcs7_aa.asn1
@@ -0,0 +1,18 @@
+-- SPDX-License-Identifier: BSD-3-Clause
+--
+-- Copyright (C) 2009 IETF Trust and the persons identified as authors
+-- of the code
+--
+-- https://www.rfc-editor.org/rfc/rfc5652#section-3
+
+AA ::= 	CHOICE {
+	aaSet		[0] IMPLICIT AASet,
+	aaSequence	[2] EXPLICIT SEQUENCE OF AuthenticatedAttribute
+}
+
+AASet ::= SET OF AuthenticatedAttribute
+
+AuthenticatedAttribute ::= SEQUENCE {
+	type	OBJECT IDENTIFIER ({ pkcs7_aa_note_OID }),
+	values	SET OF ANY ({ pkcs7_aa_note_attr })
+}
diff --git a/crypto/asymmetric_keys/pkcs7_parser.c b/crypto/asymmetric_keys/pkcs7_parser.c
index 6e3ffdac83ace..d467866f7d930 100644
--- a/crypto/asymmetric_keys/pkcs7_parser.c
+++ b/crypto/asymmetric_keys/pkcs7_parser.c
@@ -15,6 +15,7 @@
 #include <crypto/public_key.h>
 #include "pkcs7_parser.h"
 #include "pkcs7.asn1.h"
+#include "pkcs7_aa.asn1.h"
 
 MODULE_DESCRIPTION("PKCS#7 parser");
 MODULE_AUTHOR("Red Hat, Inc.");
@@ -211,6 +212,86 @@ int pkcs7_get_content_data(const struct pkcs7_message *pkcs7,
 }
 EXPORT_SYMBOL_GPL(pkcs7_get_content_data);
 
+struct pkcs7_aa_context {
+	bool found;
+	enum OID oid_to_find;
+	const void *data;
+	size_t len;
+};
+
+int pkcs7_aa_note_OID(void *context, size_t hdrlen,
+		      unsigned char tag,
+		      const void *value, size_t vlen)
+{
+	struct pkcs7_aa_context *ctx = context;
+	enum OID oid = look_up_OID(value, vlen);
+
+	ctx->found = (oid == ctx->oid_to_find);
+
+	return 0;
+}
+
+int pkcs7_aa_note_attr(void *context, size_t hdrlen,
+		       unsigned char tag,
+		       const void *value, size_t vlen)
+{
+	struct pkcs7_aa_context *ctx = context;
+
+	if (ctx->found) {
+		ctx->data = value;
+		ctx->len = vlen;
+	}
+
+	return 0;
+}
+
+/**
+ * pkcs7_get_authattr - get authenticated attribute by OID
+ * @pkcs7: The preparsed PKCS#7 message
+ * @oid: the enum value of the OID to find
+ * @_data: Place to return a pointer to the attribute value
+ * @_len: length of the attribute value
+ *
+ * Searches the authenticated attributes until one is found with a
+ * matching OID.  Note that because the attributes are per signer
+ * there could be multiple signers with different values, but this
+ * routine will simply return the first one in parse order.
+ *
+ * Returns -ENODATA if the attribute can't be found
+ */
+int pkcs7_get_authattr(const struct pkcs7_message *pkcs7,
+		       enum OID oid,
+		       const void **_data, size_t *_len)
+{
+	struct pkcs7_signed_info *sinfo = pkcs7->signed_infos;
+	struct pkcs7_aa_context ctx;
+
+	ctx.data = NULL;
+	ctx.oid_to_find = oid;
+
+	for (; sinfo; sinfo = sinfo->next) {
+		int ret;
+
+		/* only extract OIDs from validated signers */
+		if (!sinfo->verified)
+			continue;
+
+		ret = asn1_ber_decoder(&pkcs7_aa_decoder, &ctx,
+				       sinfo->authattrs, sinfo->authattrs_len);
+		if (ret < 0 || ctx.data != NULL)
+			break;
+	}
+
+	if (!ctx.data)
+		return -ENODATA;
+
+	*_data = ctx.data;
+	*_len = ctx.len;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pkcs7_get_authattr);
+
 /*
  * Note an OID when we find one for later processing when we know how
  * to interpret it.
diff --git a/include/crypto/pkcs7.h b/include/crypto/pkcs7.h
index 38ec7f5f90411..bd83202cd805c 100644
--- a/include/crypto/pkcs7.h
+++ b/include/crypto/pkcs7.h
@@ -25,6 +25,10 @@ extern void pkcs7_free_message(struct pkcs7_message *pkcs7);
 extern int pkcs7_get_content_data(const struct pkcs7_message *pkcs7,
 				  const void **_data, size_t *_datalen,
 				  size_t *_headerlen);
+extern int pkcs7_get_authattr(const struct pkcs7_message *pkcs7,
+			      enum OID oid,
+			      const void **_data, size_t *_len);
+
 
 /*
  * pkcs7_trust.c
-- 
2.53.0

[PATCH v4 03/10] crypto: pkcs7: add tests for pkcs7_get_authattr

[Blaise Boscaccy]

From: James Bottomley <James.Bottomley@HansenPartnership.com>

Add example code to the test module pkcs7_key_type.c that verifies a
message and then pulls out a known authenticated attribute.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Blaise Boscaccy <bboscaccy@linux.microsoft.com>
Acked-by: David Howells <dhowells@redhat.com>
---
 crypto/asymmetric_keys/pkcs7_key_type.c | 44 ++++++++++++++++++++++++-
 1 file changed, 43 insertions(+), 1 deletion(-)

diff --git a/crypto/asymmetric_keys/pkcs7_key_type.c b/crypto/asymmetric_keys/pkcs7_key_type.c
index b930d3bbf1af5..e0b1ce0202f6d 100644
--- a/crypto/asymmetric_keys/pkcs7_key_type.c
+++ b/crypto/asymmetric_keys/pkcs7_key_type.c
@@ -12,6 +12,7 @@
 #include <linux/verification.h>
 #include <linux/key-type.h>
 #include <keys/user-type.h>
+#include <crypto/pkcs7.h>
 
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("PKCS#7 testing key type");
@@ -51,16 +52,57 @@ static int pkcs7_view_content(void *ctx, const void *data, size_t len,
 static int pkcs7_preparse(struct key_preparsed_payload *prep)
 {
 	enum key_being_used_for usage = pkcs7_usage;
+	int ret;
+	struct pkcs7_message *pkcs7;
+	const void *data;
+	size_t len;
 
 	if (usage >= NR__KEY_BEING_USED_FOR) {
 		pr_err("Invalid usage type %d\n", usage);
 		return -EINVAL;
 	}
 
-	return verify_pkcs7_signature(NULL, 0,
+	ret = verify_pkcs7_signature(NULL, 0,
 				      prep->data, prep->datalen,
 				      VERIFY_USE_SECONDARY_KEYRING, usage,
 				      pkcs7_view_content, prep);
+	if (ret)
+		return ret;
+
+	pkcs7 = pkcs7_parse_message(prep->data, prep->datalen);
+	if (IS_ERR(pkcs7)) {
+		pr_err("pkcs7 parse error\n");
+		return PTR_ERR(pkcs7);
+	}
+
+	/*
+	 * the parsed message has no trusted signer, so nothing should
+	 * be returned here
+	 */
+	ret = pkcs7_get_authattr(pkcs7, OID_messageDigest, &data, &len);
+	if (ret == 0) {
+		pr_err("OID returned when no trust in signer\n");
+		goto out;
+	}
+	/* add trust and check again */
+	ret = verify_pkcs7_message_sig(NULL, 0, pkcs7,
+				       VERIFY_USE_SECONDARY_KEYRING, usage,
+				       NULL, NULL);
+	if (ret) {
+		pr_err("verify_pkcs7_message_sig failed!!\n");
+		goto out;
+	}
+	/* now we should find the OID */
+	ret = pkcs7_get_authattr(pkcs7, OID_messageDigest, &data, &len);
+	if (ret) {
+		pr_err("Failed to get message digest\n");
+		goto out;
+	}
+	pr_info("Correctly Got message hash, size=%zu\n", len);
+
+ out:
+	pkcs7_free_message(pkcs7);
+	return 0;
 }
 
 /*
-- 
2.53.0

[PATCH v4 04/10] lsm: framework for BPF integrity verification

[Blaise Boscaccy]

From: Paul Moore <paul@paul-moore.com>

Add a new LSM hook and two new LSM hook callbacks to support LSMs that
perform integrity verification, e.g. digital signature verification,
of BPF programs.

While the BPF subsystem does implement a signature verification scheme,
it does not satisfy a number of existing requirements, adding support
for BPF program integrity verification to the LSM framework allows
administrators to select additional integrity verification mechanisms
to meet these needs while also providing a mechanism for future
expansion.  Additional on why this is necessary can be found at the
lore archive link below:

https://lore.kernel.org/linux-security-module/CAHC9VhTQ_DR=ANzoDBjcCtrimV7XcCZVUsANPt=TjcvM4d-vjg@mail.gmail.com/

The LSM-based BPF integrity verification mechanism works within the
existing security_bpf_prog_load() hook called by the BPF subsystem.
It adds an additional dedicated integrity callback and a new LSM
hook/callback to be called from within LSMs implementing integrity
verification.

The first new callback, bpf_prog_load_integrity(), located within the
security_bpf_prog_load() hook, is necessary to ensure that the integrity
verification callbacks are executed before any of the existing LSMs
are executed via the bpf_prog_load() callback.  Reusing the existing
bpf_prog_load() callback for integrity verification could result in LSMs
not having access to the integrity verification results when asked to
authorize the BPF program load in the bpf_prog_load() callback.

The new LSM hook, security_bpf_prog_load_post_integrity(), is intended
to be called from within LSMs performing BPF program integrity
verification.  It is used to report the verdict of the integrity
verification to other LSMs enforcing access control policy on BPF
program loads.  LSMs enforcing such access controls should register a
bpf_prog_load_post_integrity() callback to receive integrity verdicts.

More information on these new callbacks and hook can be found in the
code comments in this patch.

Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Blaise Boscaccy <bboscaccy@linux.microsoft.com>
---
 include/linux/lsm_hook_defs.h |  5 +++
 include/linux/security.h      | 25 ++++++++++++
 security/security.c           | 75 +++++++++++++++++++++++++++++++++--
 3 files changed, 102 insertions(+), 3 deletions(-)

diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index 8c42b4bde09c0..4971d3c36d5b4 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -434,6 +434,11 @@ LSM_HOOK(int, 0, bpf_prog, struct bpf_prog *prog)
 LSM_HOOK(int, 0, bpf_map_create, struct bpf_map *map, union bpf_attr *attr,
 	 struct bpf_token *token, bool kernel)
 LSM_HOOK(void, LSM_RET_VOID, bpf_map_free, struct bpf_map *map)
+LSM_HOOK(int, 0, bpf_prog_load_post_integrity, struct bpf_prog *prog,
+	 union bpf_attr *attr, struct bpf_token *token, bool kernel,
+	 const struct lsm_id *lsmid, enum lsm_integrity_verdict verdict)
+LSM_HOOK(int, 0, bpf_prog_load_integrity, struct bpf_prog *prog,
+	 union bpf_attr *attr, struct bpf_token *token, bool kernel)
 LSM_HOOK(int, 0, bpf_prog_load, struct bpf_prog *prog, union bpf_attr *attr,
 	 struct bpf_token *token, bool kernel)
 LSM_HOOK(void, LSM_RET_VOID, bpf_prog_free, struct bpf_prog *prog)
diff --git a/include/linux/security.h b/include/linux/security.h
index ee88dd2d2d1f7..b3fd04baa78d0 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -67,6 +67,7 @@ enum fs_value_type;
 struct watch;
 struct watch_notification;
 struct lsm_ctx;
+struct lsm_id;
 
 /* Default (no) options for the capable function */
 #define CAP_OPT_NONE 0x0
@@ -100,6 +101,14 @@ enum lsm_integrity_type {
 	LSM_INT_FSVERITY_BUILTINSIG_VALID,
 };
 
+enum lsm_integrity_verdict {
+	LSM_INT_VERDICT_NONE = 0,
+	LSM_INT_VERDICT_OK,
+	LSM_INT_VERDICT_UNSIGNED,
+	LSM_INT_VERDICT_PARTIALSIG,
+	LSM_INT_VERDICT_BADSIG,
+};
+
 /*
  * These are reasons that can be passed to the security_locked_down()
  * LSM hook. Lockdown reasons that protect kernel integrity (ie, the
@@ -2270,6 +2279,12 @@ extern int security_bpf_prog(struct bpf_prog *prog);
 extern int security_bpf_map_create(struct bpf_map *map, union bpf_attr *attr,
 				   struct bpf_token *token, bool kernel);
 extern void security_bpf_map_free(struct bpf_map *map);
+extern int security_bpf_prog_load_post_integrity(struct bpf_prog *prog,
+					union bpf_attr *attr,
+					struct bpf_token *token,
+					bool kernel,
+					const struct lsm_id *lsmid,
+					enum lsm_integrity_verdict verdict);
 extern int security_bpf_prog_load(struct bpf_prog *prog, union bpf_attr *attr,
 				  struct bpf_token *token, bool kernel);
 extern void security_bpf_prog_free(struct bpf_prog *prog);
@@ -2304,6 +2319,16 @@ static inline int security_bpf_map_create(struct bpf_map *map, union bpf_attr *a
 static inline void security_bpf_map_free(struct bpf_map *map)
 { }
 
+static inline int security_bpf_prog_load_post_integrity(struct bpf_prog *prog,
+					  union bpf_attr *attr,
+					  struct bpf_token *token,
+					  bool kernel,
+					  const struct lsm_id *lsmid,
+					  enum lsm_integrity_verdict verdict)
+{
+	return 0;
+}
+
 static inline int security_bpf_prog_load(struct bpf_prog *prog, union bpf_attr *attr,
 					 struct bpf_token *token, bool kernel)
 {
diff --git a/security/security.c b/security/security.c
index a26c1474e2e49..bb78f7e45a98f 100644
--- a/security/security.c
+++ b/security/security.c
@@ -5233,6 +5233,50 @@ int security_bpf_map_create(struct bpf_map *map, union bpf_attr *attr,
 	return rc;
 }
 
+/**
+ * security_bpf_prog_load_post_integrity() - Check if the BPF prog is allowed
+ * @prog: BPF program object
+ * @attr: BPF syscall attributes used to create BPF program
+ * @token: BPF token used to grant user access to BPF subsystem
+ * @kernel: whether or not call originated from kernel
+ * @lsmid: LSM ID of the LSM providing @verdict
+ * @verdict: result of the integrity verification
+ *
+ * See the comment block for the security_bpf_prog_load() LSM hook.
+ *
+ * This LSM hook is intended to be called from within the
+ * bpf_prog_load_integrity() callback that is part of the
+ * security_bpf_prog_load() hook; kernel subsystems outside the scope of the
+ * LSM framework should not call this hook directly.
+ *
+ * If the LSM calling into this hook receives a non-zero error code, it should
+ * return the same error code back to its caller.  If this hook returns a zero,
+ * it does not necessarily mean that all of the enabled LSMs have authorized
+ * the BPF program load, as there may be other LSMs implementing BPF integrity
+ * checks which have yet to execute.  However, if a zero is returned, the LSM
+ * calling into this hook should continue and return zero back to its caller.
+ *
+ * LSMs which implement the bpf_prog_load_post_integrity() callback and
+ * determine that a particular BPF program load is not authorized may choose to
+ * either return an error code for immediate rejection, or store their decision
+ * in their own LSM state attached to @prog, later returning an error code in
+ * the bpf_prog_load() callback.  An immediate error code return is in keeping
+ * with the "fail fast" practice, but waiting until the bpf_prog_load()
+ * callback allows the LSM to consider multiple different integrity verdicts.
+ *
+ * Return: Returns 0 on success, error on failure.
+ */
+int security_bpf_prog_load_post_integrity(struct bpf_prog *prog,
+					  union bpf_attr *attr,
+					  struct bpf_token *token,
+					  bool kernel,
+					  const struct lsm_id *lsmid,
+					  enum lsm_integrity_verdict verdict)
+{
+	return call_int_hook(bpf_prog_load_post_integrity, prog, attr, token,
+			     kernel, lsmid, verdict);
+}
+
 /**
  * security_bpf_prog_load() - Check if loading of BPF program is allowed
  * @prog: BPF program object
@@ -5241,8 +5285,24 @@ int security_bpf_map_create(struct bpf_map *map, union bpf_attr *attr,
  * @kernel: whether or not call originated from kernel
  *
  * Perform an access control check when the kernel loads a BPF program and
- * allocates associated BPF program object. This hook is also responsible for
- * allocating any required LSM state for the BPF program.
+ * allocates the associated BPF program object. This hook is also responsible
+ * for allocating any required LSM state for the BPF program.
+ *
+ * This hook calls two LSM callbacks: bpf_prog_load_integrity() and
+ * bpf_prog_load().  The bpf_prog_load_integrity() callback is for those LSMs
+ * that wish to implement integrity verifications of BPF programs, e.g.
+ * signature verification, while the bpf_prog_load() callback is for general
+ * authorization of the BPF program load.  Performing both verification and
+ * authorization in a single callback, with arbitrary LSM ordering, would be
+ * a challenge.
+ *
+ * LSMs which implement the bpf_prog_load_integrity() callback should call into
+ * the security_bpf_prog_load_post_integrity() hook with their integrity
+ * verdict.  LSMs which implement BPF program integrity policy can register a
+ * callback for the security_bpf_prog_load_post_integrity() hook and
+ * either update their own internal state based on the verdict, or immediately
+ * reject the BPF program load with an error code.  See the comment block for
+ * security_bpf_prog_load_post_integrity() for more information.
  *
  * Return: Returns 0 on success, error on failure.
  */
@@ -5255,9 +5315,18 @@ int security_bpf_prog_load(struct bpf_prog *prog, union bpf_attr *attr,
 	if (unlikely(rc))
 		return rc;
 
+	rc = call_int_hook(bpf_prog_load_integrity, prog, attr, token, kernel);
+	if (unlikely(rc))
+		goto err;
+
 	rc = call_int_hook(bpf_prog_load, prog, attr, token, kernel);
 	if (unlikely(rc))
-		security_bpf_prog_free(prog);
+		goto err;
+
+	return rc;
+
+err:
+	security_bpf_prog_free(prog);
 	return rc;
 }
 
-- 
2.53.0

[PATCH v4 05/10] lsm: security: Add additional enum values for bpf integrity checks

[Blaise Boscaccy]

First add a generic LSM_INT_VERDICT_FAULT value to indicate a system
failure during checking. Second, add a LSM_INT_VERDICT_UNKNOWNKEY to
signal that the payload was signed with a key other than one that
exists in the secondary keyring. And finally add an
LSM_INT_VERDICT_UNEXPECTED enum value to indicate that a unexpected
hash value was encountered at some stage of verification.

Signed-off-by: Blaise Boscaccy <bboscaccy@linux.microsoft.com>
---
 include/linux/security.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/include/linux/security.h b/include/linux/security.h
index b3fd04baa78d0..4b4b8808f67de 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -106,6 +106,9 @@ enum lsm_integrity_verdict {
 	LSM_INT_VERDICT_OK,
 	LSM_INT_VERDICT_UNSIGNED,
 	LSM_INT_VERDICT_PARTIALSIG,
+	LSM_INT_VERDICT_UNKNOWNKEY,
+	LSM_INT_VERDICT_UNEXPECTED,
+	LSM_INT_VERDICT_FAULT,
 	LSM_INT_VERDICT_BADSIG,
 };
 
-- 
2.53.0

[PATCH v4 06/10] security: Hornet LSM

[Blaise Boscaccy]

This adds the Hornet Linux Security Module which provides enhanced
signature verification and data validation for eBPF programs. This
allows users to continue to maintain an invariant that all code
running inside of the kernel has actually been signed and verified, by
the kernel.

This effort builds upon the currently excepted upstream solution. It
further hardens it by providing deterministic, in-kernel checking of
map hashes to solidify auditing along with preventing TOCTOU attacks
against lskel map hashes.

Target map hashes are passed in via PKCS#7 signed attributes. Hornet
determines the extent which the eBFP program is signed and defers to
other LSMs for policy decisions.

Signed-off-by: Blaise Boscaccy <bboscaccy@linux.microsoft.com>
Nacked-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
---
 Documentation/admin-guide/LSM/Hornet.rst | 321 +++++++++++++++++++++
 Documentation/admin-guide/LSM/index.rst  |   1 +
 MAINTAINERS                              |   9 +
 include/linux/oid_registry.h             |   3 +
 include/uapi/linux/lsm.h                 |   1 +
 security/Kconfig                         |   3 +-
 security/Makefile                        |   1 +
 security/hornet/Kconfig                  |  11 +
 security/hornet/Makefile                 |   7 +
 security/hornet/hornet.asn1              |  13 +
 security/hornet/hornet_lsm.c             | 346 +++++++++++++++++++++++
 11 files changed, 715 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/admin-guide/LSM/Hornet.rst
 create mode 100644 security/hornet/Kconfig
 create mode 100644 security/hornet/Makefile
 create mode 100644 security/hornet/hornet.asn1
 create mode 100644 security/hornet/hornet_lsm.c

diff --git a/Documentation/admin-guide/LSM/Hornet.rst b/Documentation/admin-guide/LSM/Hornet.rst
new file mode 100644
index 0000000000000..af5e9cd9d83a8
--- /dev/null
+++ b/Documentation/admin-guide/LSM/Hornet.rst
@@ -0,0 +1,321 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+======
+Hornet
+======
+
+Hornet is a Linux Security Module that provides extensible signature
+verification for eBPF programs. This is selectable at build-time with
+``CONFIG_SECURITY_HORNET``.
+
+Overview
+========
+
+Hornet addresses concerns from users who require strict audit trails and
+verification guarantees for eBPF programs, especially in
+security-sensitive environments. Many production systems need assurance
+that only authorized, unmodified eBPF programs are loaded into the
+kernel. Hornet provides this assurance through cryptographic signature
+verification.
+
+When an eBPF program is loaded via the ``bpf()`` syscall, Hornet
+verifies a PKCS#7 signature attached to the program instructions. The
+signature is checked against the kernel's secondary keyring using the
+existing kernel cryptographic infrastructure. In addition to signing the
+program bytecode, Hornet supports signing SHA-256 hashes of associated
+BPF maps, enabling integrity verification of map contents at load time
+and at runtime.
+
+After verification, Hornet classifies the program into one of the
+following integrity states and passes the result to a downstream LSM hook
+(``bpf_prog_load_post_integrity``), allowing other security modules to
+make policy decisions based on the verification outcome:
+
+``LSM_INT_VERDICT_OK``
+  The program signature and all map hashes verified successfully.
+
+``LSM_INT_VERDICT_UNSIGNED``
+  No signature was provided with the program.
+
+``LSM_INT_VERDICT_PARTIALSIG``
+  The program signature verified, but the signature did not contain
+  hornet map hash data.
+
+``LSM_INT_VERDICT_UNKNOWNKEY``
+  The signing certificate is not trusted in the secondary keyring,
+
+``LSM_INT_VERDICT_FAULT``
+  A system error occured during verification.
+
+``LSM_INT_VERDICT_UNEXPECTED``
+  An unexpected map hash value was encountered.
+
+``LSM_INT_VERDICT_BADSIG``
+  The signature or a map hash failed verification.
+
+Hornet itself does not enforce a policy on whether unsigned or partially
+signed programs should be rejected. It delegates that decision to
+downstream LSMs via the ``bpf_prog_load_post_integrity`` hook, making it
+a composable building block in a larger security architecture.
+
+Use Cases
+=========
+
+- **Locked-down production environments**: Ensure only eBPF programs
+  signed by a trusted authority can be loaded, preventing unauthorized
+  or tampered programs from running in the kernel.
+
+- **Audit and compliance**: Provide cryptographic evidence that loaded
+  eBPF programs match their expected build artifacts, supporting
+  compliance requirements in regulated industries.
+
+- **Supply chain integrity**: Verify that eBPF programs and their
+  associated map data have not been modified since they were built and
+  signed, protecting against supply chain attacks.
+
+Threat Model
+============
+
+Hornet protects against the following threats:
+
+- **Unauthorized eBPF program loading**: Programs that have not been
+  signed by a trusted key will be reported as unsigned or badly signed.
+
+- **Tampering with program instructions**: Any modification to the eBPF
+  bytecode after signing will cause signature verification to fail.
+
+- **Tampering with map data**: When map hashes are included in the
+  signature, Hornet verifies that frozen BPF maps match their expected
+  SHA-256 hashes at load time. Maps are also re-verified before program
+  execution via ``BPF_PROG_RUN``.
+
+Hornet does **not** protect against:
+
+- Compromise of the signing key itself.
+- Attacks that occur after a program has been loaded and verified.
+- Programs loaded by the kernel itself (kernel-internal loads bypass
+  the ``BPF_PROG_RUN`` map check).
+
+Known Limitations
+=================
+
+- Hornet requires programs to use :doc:`light skeletons
+  </bpf/libbpf/libbpf_naming_convention>` (lskels) for the signing
+  workflow, as the tooling operates on lskel-generated headers.
+
+- A maximum of 64 maps per program can be tracked for hash
+  verification.
+
+- Map hash verification requires the maps to be frozen before loading.
+  Maps that are not frozen at load time will cause verification to fail
+  when their hashes are included in the signature.
+
+- Hornet relies on the kernel's secondary keyring
+  (``VERIFY_USE_SECONDARY_KEYRING``) for certificate trust. Keys must
+  be provisioned into this keyring before programs can be verified.
+
+- The only hashing algorithm available is SHA256 due to it be hardcoded
+  in the bpf subsystem.
+
+Configuration
+=============
+
+Build Configuration
+-------------------
+
+Enable Hornet by setting the following kernel configuration option::
+
+  CONFIG_SECURITY_HORNET=y
+
+This option is found under :menuselection:`Security options --> Hornet
+support` and depends on ``CONFIG_SECURITY``.
+
+When enabled, Hornet is included in the default LSM initialization order
+and will appear in ``/sys/kernel/security/lsm``.
+
+Architecture
+============
+
+Signature Verification Flow
+---------------------------
+
+The following describes what happens when a userspace program calls
+``bpf(BPF_PROG_LOAD, ...)`` with a signature attached:
+
+1. The ``bpf_prog_load_integrity`` LSM hook is invoked.
+
+2. Hornet reads the signature from the userspace buffer specified by
+   ``attr->signature`` (with length ``attr->signature_size``).
+
+3. The PKCS#7 signature is verified against the program instructions
+   using ``verify_pkcs7_signature()`` with the kernel's secondary
+   keyring.
+
+4. The PKCS#7 message is parsed and its trust chain is validated via
+   ``validate_pkcs7_trust()``.
+
+5. Hornet extracts the authenticated attribute identified by
+   ``OID_hornet_data`` (OID ``2.25.316487325684022475439036912669789383960``)
+   from the PKCS#7 message. This attribute contains an ASN.1-encoded set
+   of map index/hash pairs.
+
+6. For each map hash entry, Hornet retrieves the corresponding BPF map
+   via its file descriptor, confirms it is frozen, computes its SHA-256
+   hash, and compares it against the signed hash.
+
+7. The resulting integrity verdict is passed to the
+   ``bpf_prog_load_post_integrity`` hook so that downstream LSMs can
+   enforce policy.
+
+Runtime Map Verification
+------------------------
+
+When ``bpf(BPF_PROG_RUN, ...)`` is called from userspace, Hornet
+re-verifies the hashes of all maps associated with the program. This
+ensures that map contents have not been modified between program load
+and execution. If any map hash no longer matches, the ``BPF_PROG_RUN``
+command is denied.
+
+Userspace Interface
+-------------------
+
+Signatures are passed to the kernel through fields in ``union bpf_attr``
+when using the ``BPF_PROG_LOAD`` command:
+
+``signature``
+  A pointer to a userspace buffer containing the PKCS#7 signature.
+
+``signature_size``
+  The size of the signature buffer in bytes.
+
+ASN.1 Schema
+------------
+
+Map hashes are encoded as a signed attribute in the PKCS#7 message using
+the following ASN.1 schema::
+
+  HornetData ::= SET OF Map
+
+  Map ::= SEQUENCE {
+      index   INTEGER,
+      sha     OCTET STRING
+  }
+
+Each ``Map`` entry contains the index of the map in the program's
+``fd_array`` and its expected SHA-256 hash. A zero-length ``sha`` field
+indicates that the map at that index should be skipped during
+verification.
+
+Tooling
+=======
+
+Helper scripts and a signature generation tool are provided in
+``scripts/hornet/`` to support the development of signed eBPF light
+skeletons.
+
+gen_sig
+-------
+
+``gen_sig`` is a C program (using OpenSSL) that creates a PKCS#7
+signature over eBPF program instructions and optionally includes
+SHA-256 hashes of BPF maps as signed attributes.
+
+Usage::
+
+  gen_sig --data <instructions.bin> \
+          --cert <signer.crt> \
+          --key <signer.key> \
+          [--pass <passphrase>] \
+          --out <signature.p7b> \
+          [--add <mapfile.bin>:<index> ...]
+
+``--data``
+  Path to the binary file containing eBPF program instructions to sign.
+
+``--cert``
+  Path to the signing certificate (PEM or DER format).
+
+``--key``
+  Path to the private key (PEM or DER format).
+
+``--pass``
+  Optional passphrase for the private key.
+
+``--out``
+  Path to write the output PKCS#7 signature.
+
+``--add``
+  Attach a map hash as a signed attribute. The argument is a path to a
+  binary map file followed by a colon and the map's index in the
+  ``fd_array``. This option may be specified multiple times.
+
+extract-skel.sh
+---------------
+
+Extracts a named field from an autogenerated eBPF lskel header file.
+Used internally by other helper scripts.
+
+extract-insn.sh
+---------------
+
+Extracts the eBPF program instructions (``opts_insn``) from an lskel
+header into a binary file suitable for signing with ``gen_sig``.
+
+extract-map.sh
+--------------
+
+Extracts the map data (``opts_data``) from an lskel header into a
+binary file suitable for hashing with ``gen_sig``.
+
+write-sig.sh
+------------
+
+Replaces the signature data in an lskel header with a new signature
+from a binary file. This is used to embed a freshly generated signature
+back into the header after signing.
+
+Signing Workflow
+================
+
+A typical workflow for building and signing an eBPF light skeleton is:
+
+1. **Compile the eBPF program**::
+
+     clang -O2 -target bpf -c program.bpf.c -o program.bpf.o
+
+2. **Generate the light skeleton header** using ``bpftool``::
+
+     bpftool gen skeleton -S program.bpf.o > loader.h
+
+3. **Extract instructions and map data** from the generated header::
+
+     scripts/hornet/extract-insn.sh loader.h > insn.bin
+     scripts/hornet/extract-map.sh loader.h > map.bin
+
+4. **Generate the signature** with ``gen_sig``::
+
+     scripts/hornet/gen_sig \
+       --key signing_key.pem \
+       --cert signing_key.x509 \
+       --data insn.bin \
+       --add map.bin:0 \
+       --out sig.bin
+
+5. **Embed the signature** back into the header::
+
+     scripts/hornet/write-sig.sh loader.h sig.bin > signed_loader.h
+
+6. **Build the loader program** using the signed header::
+
+     cc -o loader loader.c -lbpf
+
+The resulting loader program will pass the embedded signature to the
+kernel when loading the eBPF program, enabling Hornet to verify it.
+
+Testing
+=======
+
+Self-tests are provided in ``tools/testing/selftests/hornet/``. The test
+suite builds a minimal eBPF program (``trivial.bpf.c``), signs it using
+the workflow described above, and verifies that the signed program loads
+successfully.
diff --git a/Documentation/admin-guide/LSM/index.rst b/Documentation/admin-guide/LSM/index.rst
index b44ef68f6e4da..57f6e9fbe5fd1 100644
--- a/Documentation/admin-guide/LSM/index.rst
+++ b/Documentation/admin-guide/LSM/index.rst
@@ -49,3 +49,4 @@ subdirectories.
    SafeSetID
    ipe
    landlock
+   Hornet
diff --git a/MAINTAINERS b/MAINTAINERS
index d1cc0e12fe1f0..0942f5453c04d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11692,6 +11692,15 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/iio/pressure/honeywell,mprls0025pa.yaml
 F:	drivers/iio/pressure/mprls0025pa*
 
+HORNET SECURITY MODULE
+M:	Blaise Boscaccy <bboscaccy@linux.microsoft.com>
+L:	linux-security-module@vger.kernel.org
+S:	Supported
+T:	git https://github.com/blaiseboscaccy/hornet.git
+F:	Documentation/admin-guide/LSM/Hornet.rst
+F:	scripts/hornet/
+F:	security/hornet/
+
 HP BIOSCFG DRIVER
 M:	Jorge Lopez <jorge.lopez2@hp.com>
 L:	platform-driver-x86@vger.kernel.org
diff --git a/include/linux/oid_registry.h b/include/linux/oid_registry.h
index ebce402854de4..bf852715aaea4 100644
--- a/include/linux/oid_registry.h
+++ b/include/linux/oid_registry.h
@@ -150,6 +150,9 @@ enum OID {
 	OID_id_ml_dsa_65,			/* 2.16.840.1.101.3.4.3.18 */
 	OID_id_ml_dsa_87,			/* 2.16.840.1.101.3.4.3.19 */
 
+	/* Hornet LSM */
+	OID_hornet_data,	  /* 2.25.316487325684022475439036912669789383960 */
+
 	OID__NR
 };
 
diff --git a/include/uapi/linux/lsm.h b/include/uapi/linux/lsm.h
index 938593dfd5daf..2ff9bcdd551e2 100644
--- a/include/uapi/linux/lsm.h
+++ b/include/uapi/linux/lsm.h
@@ -65,6 +65,7 @@ struct lsm_ctx {
 #define LSM_ID_IMA		111
 #define LSM_ID_EVM		112
 #define LSM_ID_IPE		113
+#define LSM_ID_HORNET		114
 
 /*
  * LSM_ATTR_XXX definitions identify different LSM attributes
diff --git a/security/Kconfig b/security/Kconfig
index 6a4393fce9a17..283c4a1032094 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -230,6 +230,7 @@ source "security/safesetid/Kconfig"
 source "security/lockdown/Kconfig"
 source "security/landlock/Kconfig"
 source "security/ipe/Kconfig"
+source "security/hornet/Kconfig"
 
 source "security/integrity/Kconfig"
 
@@ -274,7 +275,7 @@ config LSM
 	default "landlock,lockdown,yama,loadpin,safesetid,apparmor,selinux,smack,tomoyo,ipe,bpf" if DEFAULT_SECURITY_APPARMOR
 	default "landlock,lockdown,yama,loadpin,safesetid,tomoyo,ipe,bpf" if DEFAULT_SECURITY_TOMOYO
 	default "landlock,lockdown,yama,loadpin,safesetid,ipe,bpf" if DEFAULT_SECURITY_DAC
-	default "landlock,lockdown,yama,loadpin,safesetid,selinux,smack,tomoyo,apparmor,ipe,bpf"
+	default "landlock,lockdown,yama,loadpin,safesetid,selinux,smack,tomoyo,apparmor,ipe,hornet,bpf"
 	help
 	  A comma-separated list of LSMs, in initialization order.
 	  Any LSMs left off this list, except for those with order
diff --git a/security/Makefile b/security/Makefile
index 4601230ba442a..b68cb56e419bc 100644
--- a/security/Makefile
+++ b/security/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_CGROUPS)			+= device_cgroup.o
 obj-$(CONFIG_BPF_LSM)			+= bpf/
 obj-$(CONFIG_SECURITY_LANDLOCK)		+= landlock/
 obj-$(CONFIG_SECURITY_IPE)		+= ipe/
+obj-$(CONFIG_SECURITY_HORNET)		+= hornet/
 
 # Object integrity file lists
 obj-$(CONFIG_INTEGRITY)			+= integrity/
diff --git a/security/hornet/Kconfig b/security/hornet/Kconfig
new file mode 100644
index 0000000000000..19406aa237ac6
--- /dev/null
+++ b/security/hornet/Kconfig
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config SECURITY_HORNET
+	bool "Hornet support"
+	depends on SECURITY
+	default n
+	help
+	  This selects Hornet.
+	  Further information can be found in
+	  Documentation/admin-guide/LSM/Hornet.rst.
+
+	  If you are unsure how to answer this question, answer N.
diff --git a/security/hornet/Makefile b/security/hornet/Makefile
new file mode 100644
index 0000000000000..26b6f954f762e
--- /dev/null
+++ b/security/hornet/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_SECURITY_HORNET) := hornet.o
+
+hornet-y := hornet.asn1.o \
+	hornet_lsm.o \
+
+$(obj)/hornet.asn1.o: $(obj)/hornet.asn1.c $(obj)/hornet.asn1.h
diff --git a/security/hornet/hornet.asn1 b/security/hornet/hornet.asn1
new file mode 100644
index 0000000000000..c8d47b16b65d7
--- /dev/null
+++ b/security/hornet/hornet.asn1
@@ -0,0 +1,13 @@
+-- SPDX-License-Identifier: BSD-3-Clause
+--
+-- Copyright (C) 2009 IETF Trust and the persons identified as authors
+-- of the code
+--
+-- https://www.rfc-editor.org/rfc/rfc5652#section-3
+
+HornetData ::= SET OF Map
+
+Map ::= SEQUENCE {
+	index			INTEGER ({ hornet_map_index }),
+	sha			OCTET STRING ({ hornet_map_hash })
+} ({ hornet_next_map })
diff --git a/security/hornet/hornet_lsm.c b/security/hornet/hornet_lsm.c
new file mode 100644
index 0000000000000..f7d62fe6229c9
--- /dev/null
+++ b/security/hornet/hornet_lsm.c
@@ -0,0 +1,346 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Hornet Linux Security Module
+ *
+ * Author: Blaise Boscaccy <bboscaccy@linux.microsoft.com>
+ *
+ * Copyright (C) 2026 Microsoft Corporation
+ */
+
+#include <linux/lsm_hooks.h>
+#include <uapi/linux/lsm.h>
+#include <linux/bpf.h>
+#include <linux/verification.h>
+#include <crypto/public_key.h>
+#include <linux/module_signature.h>
+#include <crypto/pkcs7.h>
+#include <linux/sort.h>
+#include <linux/asn1_decoder.h>
+#include <linux/oid_registry.h>
+#include "hornet.asn1.h"
+
+#define MAX_USED_MAPS 64
+
+struct hornet_maps {
+	bpfptr_t fd_array;
+};
+
+/* The only hashing algorithm available is SHA256 due to it be hardcoded
+   in the bpf subsystem. */
+
+struct hornet_parse_context {
+	int indexes[MAX_USED_MAPS];
+	bool skips[MAX_USED_MAPS];
+	unsigned char hashes[SHA256_DIGEST_SIZE * MAX_USED_MAPS];
+	int hash_count;
+};
+
+struct hornet_prog_security_struct {
+	bool checked[MAX_USED_MAPS];
+	unsigned char hashes[SHA256_DIGEST_SIZE * MAX_USED_MAPS];
+};
+
+struct hornet_map_security_struct {
+	bool checked;
+	int index;
+};
+
+struct lsm_blob_sizes hornet_blob_sizes __ro_after_init = {
+	.lbs_bpf_map = sizeof(struct hornet_map_security_struct),
+	.lbs_bpf_prog = sizeof(struct hornet_prog_security_struct),
+};
+
+static inline struct hornet_prog_security_struct *
+hornet_bpf_prog_security(struct bpf_prog *prog)
+{
+	return prog->aux->security + hornet_blob_sizes.lbs_bpf_prog;
+}
+
+static inline struct hornet_map_security_struct *
+hornet_bpf_map_security(struct bpf_map *map)
+{
+	return map->security + hornet_blob_sizes.lbs_bpf_map;
+}
+
+static int hornet_verify_hashes(struct hornet_maps *maps,
+				struct hornet_parse_context *ctx,
+				struct bpf_prog *prog)
+{
+	int map_fd;
+	u32 i;
+	struct bpf_map *map;
+	int err = 0;
+	unsigned char hash[SHA256_DIGEST_SIZE];
+	struct hornet_prog_security_struct *security = hornet_bpf_prog_security(prog);
+	struct hornet_map_security_struct *map_security;
+
+	for (i = 0; i < ctx->hash_count; i++) {
+		if (ctx->skips[i])
+			continue;
+
+		err = copy_from_bpfptr_offset(&map_fd, maps->fd_array,
+					      ctx->indexes[i] * sizeof(map_fd),
+					      sizeof(map_fd));
+		if (err < 0)
+			return LSM_INT_VERDICT_FAULT;
+
+		CLASS(fd, f)(map_fd);
+		if (fd_empty(f))
+			return LSM_INT_VERDICT_FAULT;
+		if (unlikely(fd_file(f)->f_op != &bpf_map_fops))
+			return LSM_INT_VERDICT_FAULT;
+
+		map = fd_file(f)->private_data;
+		if (!map->frozen)
+			return LSM_INT_VERDICT_FAULT;
+
+		map->ops->map_get_hash(map, SHA256_DIGEST_SIZE, hash);
+
+		err = memcmp(hash, &ctx->hashes[i * SHA256_DIGEST_SIZE],
+			      SHA256_DIGEST_SIZE);
+		if (err)
+			return LSM_INT_VERDICT_UNEXPECTED;
+
+		security->checked[i] = true;
+		memcpy(&security->hashes[i * SHA256_DIGEST_SIZE], hash, SHA256_DIGEST_SIZE);
+		map_security = hornet_bpf_map_security(map);
+		map_security->checked = true;
+		map_security->index = i;
+	}
+	return LSM_INT_VERDICT_OK;
+}
+
+int hornet_next_map(void *context, size_t hdrlen,
+		     unsigned char tag,
+		     const void *value, size_t vlen)
+{
+	struct hornet_parse_context *ctx = (struct hornet_parse_context *)context;
+
+	if (++ctx->hash_count >= MAX_USED_MAPS)
+		return -EINVAL;
+	return 0;
+}
+
+int hornet_map_index(void *context, size_t hdrlen,
+		     unsigned char tag,
+		     const void *value, size_t vlen)
+{
+	struct hornet_parse_context *ctx = (struct hornet_parse_context *)context;
+
+	if (vlen > 1)
+		return -EINVAL;
+
+	ctx->indexes[ctx->hash_count] = *(u8 *)value;
+	return 0;
+}
+
+int hornet_map_hash(void *context, size_t hdrlen,
+		    unsigned char tag,
+		    const void *value, size_t vlen)
+
+{
+	struct hornet_parse_context *ctx = (struct hornet_parse_context *)context;
+
+	if (vlen != SHA256_DIGEST_SIZE && vlen != 0)
+		return -EINVAL;
+
+	if (vlen) {
+		ctx->skips[ctx->hash_count] = false;
+		memcpy(&ctx->hashes[ctx->hash_count * SHA256_DIGEST_SIZE], value, vlen);
+	} else
+		ctx->skips[ctx->hash_count] = true;
+
+	return 0;
+}
+
+static int hornet_check_program(struct bpf_prog *prog, union bpf_attr *attr,
+				struct bpf_token *token, bool is_kernel,
+				enum lsm_integrity_verdict *verdict)
+{
+	struct hornet_maps maps = {0};
+	bpfptr_t usig = make_bpfptr(attr->signature, is_kernel);
+	struct pkcs7_message *msg;
+	struct hornet_parse_context *ctx;
+	void *sig;
+	int err;
+	const void *authattrs;
+	size_t authattrs_len;
+	struct key *key;
+
+	if (!attr->signature) {
+		*verdict = LSM_INT_VERDICT_UNSIGNED;
+		return 0;
+	}
+
+	ctx = kzalloc(sizeof(struct hornet_parse_context), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	maps.fd_array = make_bpfptr(attr->fd_array, is_kernel);
+	sig = kzalloc(attr->signature_size, GFP_KERNEL);
+	if (!sig) {
+		err = -ENOMEM;
+		goto out;
+	}
+	err = copy_from_bpfptr(sig, usig, attr->signature_size);
+	if (err != 0)
+		goto cleanup_sig;
+
+	msg = pkcs7_parse_message(sig, attr->signature_size);
+	if (IS_ERR(msg)) {
+		*verdict = LSM_INT_VERDICT_BADSIG;
+		err = 0;
+		goto cleanup_sig;
+	}
+
+	if (system_keyring_id_check(attr->keyring_id) == 0)
+		key = (struct key*)(unsigned long)attr->keyring_id;
+	else
+		key = key_ref_to_ptr(lookup_user_key(attr->keyring_id, 0, KEY_DEFER_PERM_CHECK));
+
+	if (verify_pkcs7_message_sig(prog->insnsi, prog->len * sizeof(struct bpf_insn), msg,
+				     key,
+				     VERIFYING_BPF_SIGNATURE,
+				     NULL, NULL)) {
+		*verdict = LSM_INT_VERDICT_UNKNOWNKEY;
+		err = 0;
+		goto cleanup_msg;
+	}
+
+	if (pkcs7_get_authattr(msg, OID_hornet_data,
+			       &authattrs, &authattrs_len) == -ENODATA) {
+		*verdict = LSM_INT_VERDICT_PARTIALSIG;
+		err = 0;
+		goto cleanup_msg;
+	}
+
+	err = asn1_ber_decoder(&hornet_decoder, ctx, authattrs, authattrs_len);
+	if (err < 0 || authattrs == NULL) {
+		*verdict = LSM_INT_VERDICT_BADSIG;
+		err = 0;
+		goto cleanup_msg;
+	}
+
+	err = hornet_verify_hashes(&maps, ctx, prog);
+	if (err == 0)
+		*verdict = LSM_INT_VERDICT_OK;
+	else
+		*verdict = err;
+
+cleanup_msg:
+	pkcs7_free_message(msg);
+cleanup_sig:
+	kfree(sig);
+out:
+	kfree(ctx);
+	return err;
+}
+
+static const struct lsm_id hornet_lsmid = {
+	.name = "hornet",
+	.id = LSM_ID_HORNET,
+};
+
+static int hornet_bpf_prog_load_integrity(struct bpf_prog *prog, union bpf_attr *attr,
+					  struct bpf_token *token, bool is_kernel)
+{
+	enum lsm_integrity_verdict verdict;
+	int result = hornet_check_program(prog, attr, token, is_kernel, &verdict);
+
+	if (result < 0)
+		return result;
+
+	return security_bpf_prog_load_post_integrity(prog, attr, token, is_kernel,
+						     &hornet_lsmid, verdict);
+}
+
+static int hornet_verify_map(struct bpf_prog *prog, int index)
+{
+	unsigned char hash[SHA256_DIGEST_SIZE];
+	int i;
+	struct bpf_map *map;
+	struct hornet_prog_security_struct *security = hornet_bpf_prog_security(prog);
+	struct hornet_map_security_struct *map_security;
+
+	if (!security->checked[index])
+		return 0;
+
+	for (i = 0; i < prog->aux->used_map_cnt; i++) {
+		map = prog->aux->used_maps[i];
+		map_security = hornet_bpf_map_security(map);
+		if (map_security->index != index)
+			continue;
+
+		if (!map->frozen)
+			return -EPERM;
+
+		map->ops->map_get_hash(map, SHA256_DIGEST_SIZE, hash);
+		if (memcmp(hash, &security->hashes[index * SHA256_DIGEST_SIZE],
+			   SHA256_DIGEST_SIZE) != 0)
+			return -EPERM;
+		else
+			return 0;
+	}
+	return -EINVAL;
+}
+
+static int hornet_check_prog_maps(u32 ufd)
+{
+	CLASS(fd, f)(ufd);
+	struct bpf_prog *prog;
+	int i, result = 0;
+
+	if (fd_empty(f))
+		return -EBADF;
+	if (fd_file(f)->f_op != &bpf_prog_fops)
+		return -EINVAL;
+
+	prog = fd_file(f)->private_data;
+
+	mutex_lock(&prog->aux->used_maps_mutex);
+	if (!prog->aux->used_map_cnt)
+		goto out;
+
+	for (i = 0; i < prog->aux->used_map_cnt; i++) {
+		result = hornet_verify_map(prog, i);
+		if (result)
+			goto out;
+	}
+out:
+	mutex_unlock(&prog->aux->used_maps_mutex);
+	return result;
+}
+
+static int hornet_bpf(int cmd, union bpf_attr *attr, unsigned int size, bool kernel)
+{
+	/* in horent_bpf(), anything that had originated from kernel space we assume
+	   has already been checked, in some form or another, so we don't bother
+	   checking the intergity of any maps. In hornet_bpf_prog_load_integrity(),
+	   hornet doesn't make any opinion on that and delegates that to the downstream
+	   policy enforcement. */
+
+	if (cmd != BPF_PROG_RUN)
+		return 0;
+	if (kernel)
+		return 0;
+
+	return hornet_check_prog_maps(attr->test.prog_fd);
+}
+
+static struct security_hook_list hornet_hooks[] __ro_after_init = {
+	LSM_HOOK_INIT(bpf_prog_load_integrity, hornet_bpf_prog_load_integrity),
+	LSM_HOOK_INIT(bpf, hornet_bpf),
+};
+
+static int __init hornet_init(void)
+{
+	pr_info("Hornet: eBPF signature verification enabled\n");
+	security_add_hooks(hornet_hooks, ARRAY_SIZE(hornet_hooks), &hornet_lsmid);
+	return 0;
+}
+
+DEFINE_LSM(hornet) = {
+	.id = &hornet_lsmid,
+	.blobs = &hornet_blob_sizes,
+	.init = hornet_init,
+};
-- 
2.53.0

[PATCH v4 07/10] hornet: Introduce gen_sig

[Blaise Boscaccy]

This introduces the gen_sig tool. It creates a pkcs#7 signature of a
data payload. Additionally it appends a signed attribute containing a
set of hashes.

Typical usage is to provide a payload containing the light skeleton
ebpf syscall program binary and it's associated maps, which can be
extracted from the auto-generated skeleton header.

Signed-off-by: Blaise Boscaccy <bboscaccy@linux.microsoft.com>
---
 scripts/Makefile            |   1 +
 scripts/hornet/Makefile     |   5 +
 scripts/hornet/gen_sig.c    | 392 ++++++++++++++++++++++++++++++++++++
 scripts/hornet/write-sig.sh |  27 +++
 4 files changed, 425 insertions(+)
 create mode 100644 scripts/hornet/Makefile
 create mode 100644 scripts/hornet/gen_sig.c
 create mode 100755 scripts/hornet/write-sig.sh

diff --git a/scripts/Makefile b/scripts/Makefile
index 0941e5ce7b575..dea8ab91bbe4e 100644
--- a/scripts/Makefile
+++ b/scripts/Makefile
@@ -63,6 +63,7 @@ subdir-$(CONFIG_GENKSYMS) += genksyms
 subdir-$(CONFIG_GENDWARFKSYMS) += gendwarfksyms
 subdir-$(CONFIG_SECURITY_SELINUX) += selinux
 subdir-$(CONFIG_SECURITY_IPE) += ipe
+subdir-$(CONFIG_SECURITY_HORNET) += hornet
 
 # Let clean descend into subdirs
 subdir-	+= basic dtc gdb kconfig mod
diff --git a/scripts/hornet/Makefile b/scripts/hornet/Makefile
new file mode 100644
index 0000000000000..3ee41e5e9a9ff
--- /dev/null
+++ b/scripts/hornet/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0
+hostprogs-always-y	:= gen_sig
+
+HOSTCFLAGS_gen_sig.o = $(shell $(HOSTPKG_CONFIG) --cflags libcrypto 2> /dev/null)
+HOSTLDLIBS_gen_sig = $(shell $(HOSTPKG_CONFIG) --libs libcrypto 2> /dev/null || echo -lcrypto)
diff --git a/scripts/hornet/gen_sig.c b/scripts/hornet/gen_sig.c
new file mode 100644
index 0000000000000..f966516ebc99b
--- /dev/null
+++ b/scripts/hornet/gen_sig.c
@@ -0,0 +1,392 @@
+/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+ *
+ * Generate a signature for an eBPF program along with appending
+ * map hashes as signed attributes
+ *
+ * Copyright © 2025      Microsoft Corporation.
+ *
+ * Authors: Blaise Boscaccy <bboscaccy@linux.microsoft.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1
+ * of the licence, or (at your option) any later version.
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <err.h>
+#include <getopt.h>
+
+#include <openssl/cms.h>
+#include <openssl/err.h>
+#include <openssl/evp.h>
+#include <openssl/pkcs7.h>
+#include <openssl/x509.h>
+#include <openssl/pem.h>
+#include <openssl/objects.h>
+#include <openssl/asn1.h>
+#include <openssl/asn1t.h>
+#include <openssl/opensslv.h>
+#include <openssl/bio.h>
+#include <openssl/stack.h>
+
+#if OPENSSL_VERSION_MAJOR >= 3
+# define USE_PKCS11_PROVIDER
+# include <openssl/provider.h>
+# include <openssl/store.h>
+#else
+# if !defined(OPENSSL_NO_ENGINE) && !defined(OPENSSL_NO_DEPRECATED_3_0)
+#  define USE_PKCS11_ENGINE
+#  include <openssl/engine.h>
+# endif
+#endif
+#include "../ssl-common.h"
+
+#define SHA256_LEN 32
+#define BUF_SIZE   (1 << 15) // 32 KiB
+#define MAX_HASHES 64
+
+struct hash_spec {
+	char *file;
+	int index;
+};
+
+typedef struct {
+	ASN1_INTEGER *index;
+	ASN1_OCTET_STRING *hash;
+
+} HORNET_MAP;
+
+DECLARE_ASN1_FUNCTIONS(HORNET_MAP)
+ASN1_SEQUENCE(HORNET_MAP) = {
+	ASN1_SIMPLE(HORNET_MAP, index, ASN1_INTEGER),
+	ASN1_SIMPLE(HORNET_MAP, hash, ASN1_OCTET_STRING)
+} ASN1_SEQUENCE_END(HORNET_MAP);
+
+IMPLEMENT_ASN1_FUNCTIONS(HORNET_MAP)
+
+DEFINE_STACK_OF(HORNET_MAP)
+
+typedef struct {
+	STACK_OF(HORNET_MAP) * maps;
+} MAP_SET;
+
+DECLARE_ASN1_FUNCTIONS(MAP_SET)
+ASN1_SEQUENCE(MAP_SET) = {
+	ASN1_SET_OF(MAP_SET, maps, HORNET_MAP)
+} ASN1_SEQUENCE_END(MAP_SET);
+
+IMPLEMENT_ASN1_FUNCTIONS(MAP_SET)
+
+#define DIE(...) do { fprintf(stderr, __VA_ARGS__); fputc('\n', stderr); \
+		exit(EXIT_FAILURE); } while (0)
+
+static BIO *bio_open_wr(const char *path)
+{
+	BIO *b = BIO_new_file(path, "wb");
+
+	if (!b) {
+		perror(path);
+		ERR_print_errors_fp(stderr);
+		exit(EXIT_FAILURE);
+	}
+	return b;
+}
+
+static void usage(const char *prog)
+{
+	fprintf(stderr,
+		"Usage:\n"
+		"  %s --data content.bin --cert signer.crt --key signer.key [-pass pass]\n"
+		"     --out newsig.p7b \n"
+		"     --add FILE:index [--add FILE:index ...]\n",
+		prog);
+}
+
+static const char *key_pass;
+
+static int pem_pw_cb(char *buf, int len, int w, void *v)
+{
+	int pwlen;
+
+	if (!key_pass)
+		return -1;
+
+	pwlen = strlen(key_pass);
+	if (pwlen >= len)
+		return -1;
+
+	strcpy(buf, key_pass);
+
+	key_pass = NULL;
+
+	return pwlen;
+}
+
+static EVP_PKEY *read_private_key(const char *private_key_name)
+{
+	EVP_PKEY *private_key;
+	BIO *b;
+
+	b = BIO_new_file(private_key_name, "rb");
+	ERR(!b, "%s", private_key_name);
+	private_key = PEM_read_bio_PrivateKey(b, NULL, pem_pw_cb,
+					      NULL);
+	ERR(!private_key, "%s", private_key_name);
+	BIO_free(b);
+
+	return private_key;
+}
+
+static X509 *read_x509(const char *x509_name)
+{
+	unsigned char buf[2];
+	X509 *x509;
+	BIO *b;
+	int n;
+
+	b = BIO_new_file(x509_name, "rb");
+	ERR(!b, "%s", x509_name);
+
+	/* Look at the first two bytes of the file to determine the encoding */
+	n = BIO_read(b, buf, 2);
+	if (n != 2) {
+		if (BIO_should_retry(b)) {
+			fprintf(stderr, "%s: Read wanted retry\n", x509_name);
+			exit(1);
+		}
+		if (n >= 0) {
+			fprintf(stderr, "%s: Short read\n", x509_name);
+			exit(1);
+		}
+		ERR(1, "%s", x509_name);
+	}
+
+	ERR(BIO_reset(b) != 0, "%s", x509_name);
+
+	if (buf[0] == 0x30 && buf[1] >= 0x81 && buf[1] <= 0x84)
+		/* Assume raw DER encoded X.509 */
+		x509 = d2i_X509_bio(b, NULL);
+	else
+		/* Assume PEM encoded X.509 */
+		x509 = PEM_read_bio_X509(b, NULL, NULL, NULL);
+
+	BIO_free(b);
+	ERR(!x509, "%s", x509_name);
+
+	return x509;
+}
+
+static int sha256(const char *path, unsigned char out[SHA256_LEN], unsigned int *out_len)
+{
+	FILE *f;
+	int rc;
+	EVP_MD_CTX *ctx;
+	unsigned char buf[BUF_SIZE];
+	size_t n;
+	unsigned int mdlen = 0;
+
+	if (!path || !out)
+		return -1;
+
+	f = fopen(path, "rb");
+	if (!f) {
+		perror("fopen");
+		return -2;
+	}
+
+	ERR_load_crypto_strings();
+
+	rc = -3;
+	ctx = EVP_MD_CTX_new();
+	if (!ctx) {
+		rc = -4;
+		goto done;
+	}
+
+#if OPENSSL_VERSION_NUMBER >= 0x30000000L
+	if (EVP_DigestInit_ex2(ctx, EVP_sha256(), NULL) != 1) {
+		rc = -5;
+		goto done;
+	}
+#else
+	if (EVP_DigestInit_ex(ctx, EVP_sha256(), NULL) != 1) {
+		rc = -5;
+		goto done;
+	}
+#endif
+	while ((n = fread(buf, 1, sizeof(buf), f)) > 0) {
+		if (EVP_DigestUpdate(ctx, buf, n) != 1) {
+			rc = -6;
+			goto done;
+		}
+	}
+	if (ferror(f)) {
+		rc = -7;
+		goto done;
+	}
+
+	if (EVP_DigestFinal_ex(ctx, out, &mdlen) != 1) {
+		rc = -8;
+		goto done;
+	}
+	if (mdlen != SHA256_LEN) {
+		rc = -9;
+		goto done;
+	}
+
+	if (out_len)
+		*out_len = mdlen;
+	rc = 0;
+
+done:
+	EVP_MD_CTX_free(ctx);
+	fclose(f);
+	ERR_free_strings();
+	return rc;
+}
+
+static void add_hash(MAP_SET *set, unsigned char *buffer, int buffer_len, int index)
+{
+	HORNET_MAP *map = NULL;
+
+	map = HORNET_MAP_new();
+	ASN1_INTEGER_set(map->index, index);
+	ASN1_OCTET_STRING_set(map->hash, buffer, buffer_len);
+	sk_HORNET_MAP_push(set->maps, map);
+}
+
+int main(int argc, char **argv)
+{
+	const char *cert_path = NULL;
+	const char *key_path = NULL;
+	const char *data_path = NULL;
+	const char *out_path = NULL;
+
+	X509 *signer;
+	EVP_PKEY *pkey;
+	BIO *data_in;
+	CMS_ContentInfo *cms_out;
+	struct hash_spec hashes[MAX_HASHES];
+	int hash_count = 0;
+	int flags;
+	CMS_SignerInfo *si;
+	MAP_SET *set;
+	unsigned char hash_buffer[SHA256_LEN];
+	unsigned int hash_len;
+	ASN1_OBJECT *oid;
+	unsigned char *der = NULL;
+	int der_len;
+	int err;
+	BIO *b_out;
+	int i;
+	char opt;
+
+	const char *short_opts = "C:K:P:O:A:Sh";
+
+	static const struct option long_opts[] = {
+		{"cert", required_argument, 0, 'C'},
+		{"key",  required_argument, 0, 'K'},
+		{"pass",  required_argument, 0, 'P'},
+		{"out",  required_argument, 0, 'O'},
+		{"data",  required_argument, 0, 'D'},
+		{"add",  required_argument, 0, 'A'},
+		{"help",    no_argument,       0, 'h'},
+		{0, 0, 0, 0}
+	};
+
+	while ((opt = getopt_long_only(argc, argv, short_opts, long_opts, NULL)) != -1) {
+		switch (opt) {
+		case 'C':
+			cert_path = optarg;
+			break;
+		case 'K':
+			key_path = optarg;
+			break;
+		case 'P':
+			key_pass = optarg;
+			break;
+		case 'O':
+			out_path = optarg;
+			break;
+		case 'D':
+			data_path = optarg;
+			break;
+		case 'A':
+			if (strchr(optarg, ':')) {
+				hashes[hash_count].file = strsep(&optarg, ":");
+				hashes[hash_count].index = atoi(optarg);
+				hash_count++;
+			} else {
+				usage(argv[0]);
+				return EXIT_FAILURE;
+			}
+		}
+	}
+
+	if (!cert_path || !key_path || !out_path || !data_path) {
+		usage(argv[0]);
+		return EXIT_FAILURE;
+	}
+
+	OpenSSL_add_all_algorithms();
+	ERR_load_crypto_strings();
+
+	signer = read_x509(cert_path);
+	ERR(!signer, "Load cert failed");
+
+	pkey = read_private_key(key_path);
+	ERR(!pkey, "Load key failed");
+
+	data_in = BIO_new_file(data_path, "rb");
+	ERR(!data_in, "Load data failed");
+
+	cms_out = CMS_sign(NULL, NULL, NULL, NULL,
+			   CMS_NOCERTS | CMS_PARTIAL | CMS_BINARY | CMS_DETACHED);
+	ERR(!cms_out, "create cms failed");
+
+	flags = CMS_NOCERTS | CMS_PARTIAL | CMS_BINARY | CMS_NOSMIMECAP | CMS_DETACHED;
+
+	si = CMS_add1_signer(cms_out, signer, pkey, EVP_sha256(), flags);
+	ERR(!si, "add signer failed");
+
+	set = MAP_SET_new();
+	set->maps = sk_HORNET_MAP_new_null();
+
+	for (i = 0; i < hash_count; i++) {
+		sha256(hashes[i].file, hash_buffer, &hash_len);
+		add_hash(set, hash_buffer, hash_len, hashes[i].index);
+	}
+
+	oid = OBJ_txt2obj("2.25.316487325684022475439036912669789383960", 1);
+	if (!oid) {
+		ERR_print_errors_fp(stderr);
+		DIE("create oid failed");
+	}
+
+	der_len = ASN1_item_i2d((ASN1_VALUE *)set, &der, ASN1_ITEM_rptr(MAP_SET));
+	CMS_signed_add1_attr_by_OBJ(si, oid, V_ASN1_SEQUENCE, der, der_len);
+
+	err = CMS_final(cms_out, data_in, NULL, CMS_NOCERTS | CMS_BINARY);
+	ERR(!err, "cms final failed");
+
+	OPENSSL_free(der);
+	MAP_SET_free(set);
+
+	b_out = bio_open_wr(out_path);
+	ERR(!b_out, "opening output path failed");
+
+	i2d_CMS_bio_stream(b_out, cms_out, NULL, 0);
+
+	BIO_free(data_in);
+	BIO_free(b_out);
+	EVP_cleanup();
+	ERR_free_strings();
+	return 0;
+}
diff --git a/scripts/hornet/write-sig.sh b/scripts/hornet/write-sig.sh
new file mode 100755
index 0000000000000..7eaabe3bab9aa
--- /dev/null
+++ b/scripts/hornet/write-sig.sh
@@ -0,0 +1,27 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (c) 2025 Microsoft Corporation
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of version 2 of the GNU General Public
+# License as published by the Free Software Foundation.
+
+function usage() {
+    echo "Sample for rewriting an autogenerated eBPF lskel headers"
+    echo "with a new signature"
+    echo ""
+    echo "USAGE: header_file sig"
+    exit
+}
+
+ARGC=$#
+
+EXPECTED_ARGS=2
+
+if [ $ARGC -ne $EXPECTED_ARGS ] ; then
+    usage
+else
+    SIG=$(xxd -p $2 | tr -d '\n' | sed 's/\(..\)/\\\\x\1/g')
+    sed '/const char opts_sig/,/;/c\\tstatic const char opts_sig[] __attribute__((__aligned__(8))) = "\\\n'"$(printf '%s\n' "$SIG")"'\";' $1
+fi
-- 
2.53.0

[PATCH v4 08/10] hornet: Add a light skeleton data extractor scripts

[Blaise Boscaccy]

These script eases light skeleton development against Hornet by
generating a data payloads which can be used for signing a light
skeleton binary using gen_sig.

Signed-off-by: Blaise Boscaccy <bboscaccy@linux.microsoft.com>
---
 scripts/hornet/extract-insn.sh | 27 +++++++++++++++++++++++++++
 scripts/hornet/extract-map.sh  | 27 +++++++++++++++++++++++++++
 scripts/hornet/extract-skel.sh | 27 +++++++++++++++++++++++++++
 3 files changed, 81 insertions(+)
 create mode 100755 scripts/hornet/extract-insn.sh
 create mode 100755 scripts/hornet/extract-map.sh
 create mode 100755 scripts/hornet/extract-skel.sh

diff --git a/scripts/hornet/extract-insn.sh b/scripts/hornet/extract-insn.sh
new file mode 100755
index 0000000000000..52338f057ff6b
--- /dev/null
+++ b/scripts/hornet/extract-insn.sh
@@ -0,0 +1,27 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (c) 2025 Microsoft Corporation
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of version 2 of the GNU General Public
+# License as published by the Free Software Foundation.
+
+function usage() {
+    echo "Sample script for extracting instructions"
+    echo "autogenerated eBPF lskel headers"
+    echo ""
+    echo "USAGE: header_file"
+    exit
+}
+
+ARGC=$#
+
+EXPECTED_ARGS=1
+
+if [ $ARGC -ne $EXPECTED_ARGS ] ; then
+    usage
+else
+    printf $(gcc -E $1 | grep "opts_insn" | \
+		 awk -F"=" '{print $2}' | sed 's/;\+$//' | sed 's/\"//g')
+fi
diff --git a/scripts/hornet/extract-map.sh b/scripts/hornet/extract-map.sh
new file mode 100755
index 0000000000000..c309f505c6238
--- /dev/null
+++ b/scripts/hornet/extract-map.sh
@@ -0,0 +1,27 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (c) 2025 Microsoft Corporation
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of version 2 of the GNU General Public
+# License as published by the Free Software Foundation.
+
+function usage() {
+    echo "Sample script for extracting instructions"
+    echo "autogenerated eBPF lskel headers"
+    echo ""
+    echo "USAGE: header_file"
+    exit
+}
+
+ARGC=$#
+
+EXPECTED_ARGS=1
+
+if [ $ARGC -ne $EXPECTED_ARGS ] ; then
+    usage
+else
+    printf $(gcc -E $1 | grep "opts_data" | \
+		 awk -F"=" '{print $2}' | sed 's/;\+$//' | sed 's/\"//g')
+fi
diff --git a/scripts/hornet/extract-skel.sh b/scripts/hornet/extract-skel.sh
new file mode 100755
index 0000000000000..6550a86b89917
--- /dev/null
+++ b/scripts/hornet/extract-skel.sh
@@ -0,0 +1,27 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (c) 2025 Microsoft Corporation
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of version 2 of the GNU General Public
+# License as published by the Free Software Foundation.
+
+function usage() {
+    echo "Sample script for extracting instructions and map data out of"
+    echo "autogenerated eBPF lskel headers"
+    echo ""
+    echo "USAGE: header_file field"
+    exit
+}
+
+ARGC=$#
+
+EXPECTED_ARGS=2
+
+if [ $ARGC -ne $EXPECTED_ARGS ] ; then
+    usage
+else
+    printf $(gcc -E $1 | grep "static const char opts_$2" | \
+		 awk -F"=" '{print $2}' | sed 's/;\+$//' | sed 's/\"//g')
+fi
-- 
2.53.0

[PATCH v4 09/10] selftests/hornet: Add a selftest for the Hornet LSM

[Blaise Boscaccy]

This selftest contains a testcase that utilizes light skeleton eBPF
loaders and exercises hornet's map validation.

Signed-off-by: Blaise Boscaccy <bboscaccy@linux.microsoft.com>
---
 tools/testing/selftests/Makefile             |  1 +
 tools/testing/selftests/hornet/Makefile      | 63 ++++++++++++++++++++
 tools/testing/selftests/hornet/loader.c      | 21 +++++++
 tools/testing/selftests/hornet/trivial.bpf.c | 33 ++++++++++
 4 files changed, 118 insertions(+)
 create mode 100644 tools/testing/selftests/hornet/Makefile
 create mode 100644 tools/testing/selftests/hornet/loader.c
 create mode 100644 tools/testing/selftests/hornet/trivial.bpf.c

diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 450f13ba4cca9..4e2d1cd88c825 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -44,6 +44,7 @@ TARGETS += ftrace
 TARGETS += futex
 TARGETS += gpio
 TARGETS += hid
+TARGETS += hornet
 TARGETS += intel_pstate
 TARGETS += iommu
 TARGETS += ipc
diff --git a/tools/testing/selftests/hornet/Makefile b/tools/testing/selftests/hornet/Makefile
new file mode 100644
index 0000000000000..432bce59f54e7
--- /dev/null
+++ b/tools/testing/selftests/hornet/Makefile
@@ -0,0 +1,63 @@
+# SPDX-License-Identifier: GPL-2.0
+include ../../../build/Build.include
+include ../../../scripts/Makefile.arch
+include ../../../scripts/Makefile.include
+
+CLANG ?= clang
+CFLAGS := -g -O2 -Wall
+BPFTOOL ?= $(TOOLSDIR)/bpf/bpftool/bpftool
+SCRIPTSDIR := $(abspath ../../../../scripts/hornet)
+TOOLSDIR := $(abspath ../../..)
+LIBDIR := $(TOOLSDIR)/lib
+BPFDIR := $(LIBDIR)/bpf
+TOOLSINCDIR := $(TOOLSDIR)/include
+APIDIR := $(TOOLSINCDIR)/uapi
+CERTDIR := $(abspath ../../../../certs)
+PKG_CONFIG ?= $(CROSS_COMPILE)pkg-config
+
+TEST_GEN_PROGS := loader
+TEST_GEN_FILES := vmlinux.h loader.h trivial.bpf.o map.bin sig.bin insn.bin signed_loader.h
+$(TEST_GEN_PROGS): LDLIBS += -lbpf
+$(TEST_GEN_PROGS): $(TEST_GEN_FILES)
+
+include ../lib.mk
+
+BPF_CFLAGS := -target bpf \
+	-D__TARGET_ARCH_$(ARCH) \
+	-I/usr/include/$(shell uname -m)-linux-gnu \
+	$(KHDR_INCLUDES)
+
+vmlinux.h:
+	$(BPFTOOL) btf dump file /sys/kernel/btf/vmlinux format c > vmlinux.h
+
+trivial.bpf.o: trivial.bpf.c vmlinux.h
+	$(CLANG) $(CFLAGS) $(BPF_CFLAGS) -c $< -o $@
+
+loader.h: trivial.bpf.o
+	$(BPFTOOL) gen skeleton -S -k $(CERTDIR)/signing_key.pem -i $(CERTDIR)/signing_key.x509 \
+		-L $< name trivial > $@
+
+insn.bin: loader.h
+	$(SCRIPTSDIR)/extract-insn.sh $< > $@
+
+map.bin: loader.h
+	$(SCRIPTSDIR)/extract-map.sh $< > $@
+
+$(OUTPUT)/gen_sig: ../../../../scripts/hornet/gen_sig.c
+	$(call msg,GEN_SIG,,$@)
+	$(Q)$(CC) $(shell $(PKG_CONFIG) --cflags libcrypto 2> /dev/null) \
+		  $< -o $@ \
+		  $(shell $(PKG_CONFIG) --libs libcrypto 2> /dev/null || echo -lcrypto)
+
+sig.bin: insn.bin map.bin $(OUTPUT)/gen_sig
+	$(OUTPUT)/gen_sig --key $(CERTDIR)/signing_key.pem --cert $(CERTDIR)/signing_key.x509 \
+		--data insn.bin --add map.bin:0 --out sig.bin
+
+signed_loader.h: sig.bin
+	$(SCRIPTSDIR)/write-sig.sh loader.h sig.bin > $@
+
+loader: loader.c signed_loader.h
+	$(CC) $(CFLAGS) -I$(LIBDIR) -I$(APIDIR) $< -o $@ -lbpf
+
+
+EXTRA_CLEAN = $(OUTPUT)/gen_sig
diff --git a/tools/testing/selftests/hornet/loader.c b/tools/testing/selftests/hornet/loader.c
new file mode 100644
index 0000000000000..f27580c7262b3
--- /dev/null
+++ b/tools/testing/selftests/hornet/loader.c
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+
+#include <stdio.h>
+#include <unistd.h>
+#include <stddef.h>
+#include <sys/resource.h>
+#include <bpf/libbpf.h>
+#include <errno.h>
+#include  "signed_loader.h"
+
+int main(int argc, char **argv)
+{
+	struct trivial *skel;
+
+	skel = trivial__open_and_load();
+	if (!skel)
+		return -1;
+
+	trivial__destroy(skel);
+	return 0;
+}
diff --git a/tools/testing/selftests/hornet/trivial.bpf.c b/tools/testing/selftests/hornet/trivial.bpf.c
new file mode 100644
index 0000000000000..d38c5b53ff932
--- /dev/null
+++ b/tools/testing/selftests/hornet/trivial.bpf.c
@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+
+#include "vmlinux.h"
+
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+char LICENSE[] SEC("license") = "Dual BSD/GPL";
+
+int monitored_pid = 0;
+
+SEC("tracepoint/syscalls/sys_enter_unlinkat")
+int handle_enter_unlink(struct trace_event_raw_sys_enter *ctx)
+{
+	char filename[128] = { 0 };
+	struct task_struct *task;
+	unsigned long start_time = 0;
+	int pid = bpf_get_current_pid_tgid() >> 32;
+	char *pathname_ptr = (char *) BPF_CORE_READ(ctx, args[1]);
+
+	bpf_probe_read_str(filename, sizeof(filename), pathname_ptr);
+	task = (struct task_struct *)bpf_get_current_task();
+	start_time = BPF_CORE_READ(task, start_time);
+
+	bpf_printk("BPF triggered unlinkat by PID: %d, start_time %ld. pathname = %s",
+		   pid, start_time, filename);
+
+	if (monitored_pid == pid)
+		bpf_printk("target pid found");
+
+	return 0;
+}
-- 
2.53.0

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

[Blaise Boscaccy]

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>
---
 security/ipe/Kconfig         | 14 +++++++
 security/ipe/audit.c         | 15 ++++++++
 security/ipe/eval.c          | 73 +++++++++++++++++++++++++++++++++++-
 security/ipe/eval.h          |  5 +++
 security/ipe/hooks.c         | 37 ++++++++++++++++++
 security/ipe/hooks.h         | 11 ++++++
 security/ipe/ipe.c           |  3 ++
 security/ipe/policy.h        | 14 +++++++
 security/ipe/policy_parser.c | 27 +++++++++++++
 9 files changed, 198 insertions(+), 1 deletion(-)

diff --git a/security/ipe/Kconfig b/security/ipe/Kconfig
index a110a6cd848b7..4c1d46847582b 100644
--- a/security/ipe/Kconfig
+++ b/security/ipe/Kconfig
@@ -95,6 +95,20 @@ config IPE_PROP_FS_VERITY_BUILTIN_SIG
 
 	  if unsure, answer Y.
 
+config IPE_PROP_BPF_SIGNATURE
+	bool "Enable support for Hornet BPF program signature verification"
+	depends on SECURITY_HORNET
+	help
+	  This option enables the 'bpf_signature' and 'bpf_keyring'
+	  properties within IPE policies. The 'bpf_signature' property
+	  allows IPE to make policy decisions based on the integrity
+	  verdict provided by the Hornet LSM when a BPF program is loaded.
+	  Verdicts include OK, UNSIGNED, PARTIALSIG, BADSIG, and others.
+	  The 'bpf_keyring' property allows policies to match against the
+	  keyring specified in bpf_attr (BUILTIN, SECONDARY, PLATFORM).
+
+	  If unsure, answer Y.
+
 endmenu
 
 config SECURITY_IPE_KUNIT_TEST
diff --git a/security/ipe/audit.c b/security/ipe/audit.c
index 3f0deeb549127..251c6ec2f8423 100644
--- a/security/ipe/audit.c
+++ b/security/ipe/audit.c
@@ -41,6 +41,7 @@ static const char *const audit_op_names[__IPE_OP_MAX + 1] = {
 	"KEXEC_INITRAMFS",
 	"POLICY",
 	"X509_CERT",
+	"BPF_PROG_LOAD",
 	"UNKNOWN",
 };
 
@@ -51,6 +52,7 @@ static const char *const audit_hook_names[__IPE_HOOK_MAX] = {
 	"MPROTECT",
 	"KERNEL_READ",
 	"KERNEL_LOAD",
+	"BPF_PROG_LOAD",
 };
 
 static const char *const audit_prop_names[__IPE_PROP_MAX] = {
@@ -62,6 +64,19 @@ static const char *const audit_prop_names[__IPE_PROP_MAX] = {
 	"fsverity_digest=",
 	"fsverity_signature=FALSE",
 	"fsverity_signature=TRUE",
+	"bpf_signature=NONE",
+	"bpf_signature=OK",
+	"bpf_signature=UNSIGNED",
+	"bpf_signature=PARTIALSIG",
+	"bpf_signature=UNKNOWNKEY",
+	"bpf_signature=UNEXPECTED",
+	"bpf_signature=FAULT",
+	"bpf_signature=BADSIG",
+	"bpf_keyring=BUILTIN",
+	"bpf_keyring=SECONDARY",
+	"bpf_keyring=PLATFORM",
+	"bpf_kernel=FALSE",
+	"bpf_kernel=TRUE",
 };
 
 /**
diff --git a/security/ipe/eval.c b/security/ipe/eval.c
index 21439c5be3364..9a6d583fea125 100644
--- a/security/ipe/eval.c
+++ b/security/ipe/eval.c
@@ -11,6 +11,7 @@
 #include <linux/rcupdate.h>
 #include <linux/moduleparam.h>
 #include <linux/fsverity.h>
+#include <linux/verification.h>
 
 #include "ipe.h"
 #include "eval.h"
@@ -265,8 +266,52 @@ static bool evaluate_fsv_sig_true(const struct ipe_eval_ctx *const ctx)
 }
 #endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
 
+#ifdef CONFIG_IPE_PROP_BPF_SIGNATURE
+/**
+ * evaluate_bpf_sig() - Evaluate @ctx against a bpf_signature property.
+ * @ctx: Supplies a pointer to the context being evaluated.
+ * @expected: The expected lsm_integrity_verdict to match against.
+ *
+ * Return:
+ * * %true	- The current @ctx matches the expected verdict
+ * * %false	- The current @ctx doesn't match the expected verdict
+ */
+static bool evaluate_bpf_sig(const struct ipe_eval_ctx *const ctx,
+			     enum lsm_integrity_verdict expected)
+{
+	return ctx->bpf_verdict == expected;
+}
+#else
+static bool evaluate_bpf_sig(const struct ipe_eval_ctx *const ctx,
+			     enum lsm_integrity_verdict expected)
+{
+	return false;
+}
+#endif /* CONFIG_IPE_PROP_BPF_SIGNATURE */
+
+#ifdef CONFIG_IPE_PROP_BPF_SIGNATURE
+/**
+ * evaluate_bpf_keyring() - Evaluate @ctx against a bpf_keyring property.
+ * @ctx: Supplies a pointer to the context being evaluated.
+ * @expected: The expected keyring_id to match against.
+ *
+ * Return:
+ * * %true	- The current @ctx matches the expected keyring
+ * * %false	- The current @ctx doesn't match the expected keyring
+ */
+static bool evaluate_bpf_keyring(const struct ipe_eval_ctx *const ctx,
+				 s32 expected)
+{
+	return ctx->bpf_keyring_id == expected;
+}
+#else
+static bool evaluate_bpf_keyring(const struct ipe_eval_ctx *const ctx,
+				 s32 expected)
+{
+	return false;
+}
+#endif /* CONFIG_IPE_PROP_BPF_SIGNATURE */
 /**
- * evaluate_property() - Analyze @ctx against a rule property.
  * @ctx: Supplies a pointer to the context to be evaluated.
  * @p: Supplies a pointer to the property to be evaluated.
  *
@@ -297,6 +342,32 @@ static bool evaluate_property(const struct ipe_eval_ctx *const ctx,
 		return evaluate_fsv_sig_false(ctx);
 	case IPE_PROP_FSV_SIG_TRUE:
 		return evaluate_fsv_sig_true(ctx);
+	case IPE_PROP_BPF_SIG_NONE:
+		return evaluate_bpf_sig(ctx, LSM_INT_VERDICT_NONE);
+	case IPE_PROP_BPF_SIG_OK:
+		return evaluate_bpf_sig(ctx, LSM_INT_VERDICT_OK);
+	case IPE_PROP_BPF_SIG_UNSIGNED:
+		return evaluate_bpf_sig(ctx, LSM_INT_VERDICT_UNSIGNED);
+	case IPE_PROP_BPF_SIG_PARTIALSIG:
+		return evaluate_bpf_sig(ctx, LSM_INT_VERDICT_PARTIALSIG);
+	case IPE_PROP_BPF_SIG_UNKNOWNKEY:
+		return evaluate_bpf_sig(ctx, LSM_INT_VERDICT_UNKNOWNKEY);
+	case IPE_PROP_BPF_SIG_UNEXPECTED:
+		return evaluate_bpf_sig(ctx, LSM_INT_VERDICT_UNEXPECTED);
+	case IPE_PROP_BPF_SIG_FAULT:
+		return evaluate_bpf_sig(ctx, LSM_INT_VERDICT_FAULT);
+	case IPE_PROP_BPF_SIG_BADSIG:
+		return evaluate_bpf_sig(ctx, LSM_INT_VERDICT_BADSIG);
+	case IPE_PROP_BPF_KEYRING_BUILTIN:
+		return evaluate_bpf_keyring(ctx, 0);
+	case IPE_PROP_BPF_KEYRING_SECONDARY:
+		return evaluate_bpf_keyring(ctx, (s32)(unsigned long)VERIFY_USE_SECONDARY_KEYRING);
+	case IPE_PROP_BPF_KEYRING_PLATFORM:
+		return evaluate_bpf_keyring(ctx, (s32)(unsigned long)VERIFY_USE_PLATFORM_KEYRING);
+	case IPE_PROP_BPF_KERNEL_FALSE:
+		return !ctx->bpf_kernel;
+	case IPE_PROP_BPF_KERNEL_TRUE:
+		return ctx->bpf_kernel;
 	default:
 		return false;
 	}
diff --git a/security/ipe/eval.h b/security/ipe/eval.h
index fef65a36468cb..1578d83bafc10 100644
--- a/security/ipe/eval.h
+++ b/security/ipe/eval.h
@@ -52,6 +52,11 @@ struct ipe_eval_ctx {
 #ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG
 	const struct ipe_inode *ipe_inode;
 #endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
+#ifdef CONFIG_IPE_PROP_BPF_SIGNATURE
+	enum lsm_integrity_verdict bpf_verdict;
+	s32 bpf_keyring_id;
+	bool bpf_kernel;
+#endif /* CONFIG_IPE_PROP_BPF_SIGNATURE */
 };
 
 enum ipe_match {
diff --git a/security/ipe/hooks.c b/security/ipe/hooks.c
index 0ae54a880405a..03541e5bb7f60 100644
--- a/security/ipe/hooks.c
+++ b/security/ipe/hooks.c
@@ -340,3 +340,40 @@ int ipe_inode_setintegrity(const struct inode *inode,
 	return -EINVAL;
 }
 #endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
+
+#ifdef CONFIG_IPE_PROP_BPF_SIGNATURE
+/**
+ * ipe_bpf_prog_load_post_integrity() - ipe security hook for BPF program load.
+ * @prog: Supplies the BPF program being loaded.
+ * @attr: Supplies the bpf syscall attributes.
+ * @token: Supplies the BPF token, if any.
+ * @kernel: Whether the call originated from the kernel.
+ * @lsmid: Supplies the LSM ID of the integrity provider.
+ * @verdict: Supplies the integrity verdict from the provider (e.g. Hornet).
+ *
+ * This LSM hook is called after an integrity verification LSM (such as Hornet)
+ * has evaluated a BPF program's cryptographic signature. IPE uses the verdict
+ * to make a policy-based allow/deny decision.
+ *
+ * Return:
+ * * %0		- Success
+ * * %-EACCES	- Did not pass IPE policy
+ */
+int ipe_bpf_prog_load_post_integrity(struct bpf_prog *prog,
+				     union bpf_attr *attr,
+				     struct bpf_token *token,
+				     bool kernel,
+				     const struct lsm_id *lsmid,
+				     enum lsm_integrity_verdict verdict)
+{
+	struct ipe_eval_ctx ctx = IPE_EVAL_CTX_INIT;
+
+	ctx.op = IPE_OP_BPF_PROG_LOAD;
+	ctx.hook = IPE_HOOK_BPF_PROG_LOAD;
+	ctx.bpf_verdict = verdict;
+	ctx.bpf_keyring_id = attr->keyring_id;
+	ctx.bpf_kernel = kernel;
+
+	return ipe_evaluate_event(&ctx);
+}
+#endif /* CONFIG_IPE_PROP_BPF_SIGNATURE */
diff --git a/security/ipe/hooks.h b/security/ipe/hooks.h
index 07db373327402..95b74f7899750 100644
--- a/security/ipe/hooks.h
+++ b/security/ipe/hooks.h
@@ -10,6 +10,7 @@
 #include <linux/security.h>
 #include <linux/blk_types.h>
 #include <linux/fsverity.h>
+#include <linux/bpf.h>
 
 enum ipe_hook_type {
 	IPE_HOOK_BPRM_CHECK = 0,
@@ -18,6 +19,7 @@ enum ipe_hook_type {
 	IPE_HOOK_MPROTECT,
 	IPE_HOOK_KERNEL_READ,
 	IPE_HOOK_KERNEL_LOAD,
+	IPE_HOOK_BPF_PROG_LOAD,
 	__IPE_HOOK_MAX
 };
 
@@ -52,4 +54,13 @@ int ipe_inode_setintegrity(const struct inode *inode, enum lsm_integrity_type ty
 			   const void *value, size_t size);
 #endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
 
+#ifdef CONFIG_IPE_PROP_BPF_SIGNATURE
+int ipe_bpf_prog_load_post_integrity(struct bpf_prog *prog,
+				     union bpf_attr *attr,
+				     struct bpf_token *token,
+				     bool kernel,
+				     const struct lsm_id *lsmid,
+				     enum lsm_integrity_verdict verdict);
+#endif /* CONFIG_IPE_PROP_BPF_SIGNATURE */
+
 #endif /* _IPE_HOOKS_H */
diff --git a/security/ipe/ipe.c b/security/ipe/ipe.c
index 495bb765de1b8..6502d4ddc641c 100644
--- a/security/ipe/ipe.c
+++ b/security/ipe/ipe.c
@@ -60,6 +60,9 @@ static struct security_hook_list ipe_hooks[] __ro_after_init = {
 #ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG
 	LSM_HOOK_INIT(inode_setintegrity, ipe_inode_setintegrity),
 #endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
+#ifdef CONFIG_IPE_PROP_BPF_SIGNATURE
+	LSM_HOOK_INIT(bpf_prog_load_post_integrity, ipe_bpf_prog_load_post_integrity),
+#endif /* CONFIG_IPE_PROP_BPF_SIGNATURE */
 };
 
 /**
diff --git a/security/ipe/policy.h b/security/ipe/policy.h
index 5bfbdbddeef86..748bea92beb19 100644
--- a/security/ipe/policy.h
+++ b/security/ipe/policy.h
@@ -17,6 +17,7 @@ enum ipe_op_type {
 	IPE_OP_KEXEC_INITRAMFS,
 	IPE_OP_POLICY,
 	IPE_OP_X509,
+	IPE_OP_BPF_PROG_LOAD,
 	__IPE_OP_MAX,
 };
 
@@ -39,6 +40,19 @@ enum ipe_prop_type {
 	IPE_PROP_FSV_DIGEST,
 	IPE_PROP_FSV_SIG_FALSE,
 	IPE_PROP_FSV_SIG_TRUE,
+	IPE_PROP_BPF_SIG_NONE,
+	IPE_PROP_BPF_SIG_OK,
+	IPE_PROP_BPF_SIG_UNSIGNED,
+	IPE_PROP_BPF_SIG_PARTIALSIG,
+	IPE_PROP_BPF_SIG_UNKNOWNKEY,
+	IPE_PROP_BPF_SIG_UNEXPECTED,
+	IPE_PROP_BPF_SIG_FAULT,
+	IPE_PROP_BPF_SIG_BADSIG,
+	IPE_PROP_BPF_KEYRING_BUILTIN,
+	IPE_PROP_BPF_KEYRING_SECONDARY,
+	IPE_PROP_BPF_KEYRING_PLATFORM,
+	IPE_PROP_BPF_KERNEL_FALSE,
+	IPE_PROP_BPF_KERNEL_TRUE,
 	__IPE_PROP_MAX
 };
 
diff --git a/security/ipe/policy_parser.c b/security/ipe/policy_parser.c
index 6fa5bebf84714..71f63de56616b 100644
--- a/security/ipe/policy_parser.c
+++ b/security/ipe/policy_parser.c
@@ -237,6 +237,7 @@ static const match_table_t operation_tokens = {
 	{IPE_OP_KEXEC_INITRAMFS,	"op=KEXEC_INITRAMFS"},
 	{IPE_OP_POLICY,			"op=POLICY"},
 	{IPE_OP_X509,			"op=X509_CERT"},
+	{IPE_OP_BPF_PROG_LOAD,		"op=BPF_PROG_LOAD"},
 	{IPE_OP_INVALID,		NULL}
 };
 
@@ -281,6 +282,19 @@ static const match_table_t property_tokens = {
 	{IPE_PROP_FSV_DIGEST,		"fsverity_digest=%s"},
 	{IPE_PROP_FSV_SIG_FALSE,	"fsverity_signature=FALSE"},
 	{IPE_PROP_FSV_SIG_TRUE,		"fsverity_signature=TRUE"},
+	{IPE_PROP_BPF_SIG_NONE,		"bpf_signature=NONE"},
+	{IPE_PROP_BPF_SIG_OK,		"bpf_signature=OK"},
+	{IPE_PROP_BPF_SIG_UNSIGNED,	"bpf_signature=UNSIGNED"},
+	{IPE_PROP_BPF_SIG_PARTIALSIG,	"bpf_signature=PARTIALSIG"},
+	{IPE_PROP_BPF_SIG_UNKNOWNKEY,	"bpf_signature=UNKNOWNKEY"},
+	{IPE_PROP_BPF_SIG_UNEXPECTED,	"bpf_signature=UNEXPECTED"},
+	{IPE_PROP_BPF_SIG_FAULT,	"bpf_signature=FAULT"},
+	{IPE_PROP_BPF_SIG_BADSIG,	"bpf_signature=BADSIG"},
+	{IPE_PROP_BPF_KEYRING_BUILTIN,	"bpf_keyring=BUILTIN"},
+	{IPE_PROP_BPF_KEYRING_SECONDARY,	"bpf_keyring=SECONDARY"},
+	{IPE_PROP_BPF_KEYRING_PLATFORM,	"bpf_keyring=PLATFORM"},
+	{IPE_PROP_BPF_KERNEL_FALSE,	"bpf_kernel=FALSE"},
+	{IPE_PROP_BPF_KERNEL_TRUE,	"bpf_kernel=TRUE"},
 	{IPE_PROP_INVALID,		NULL}
 };
 
@@ -331,6 +345,19 @@ static int parse_property(char *t, struct ipe_rule *r)
 	case IPE_PROP_DMV_SIG_TRUE:
 	case IPE_PROP_FSV_SIG_FALSE:
 	case IPE_PROP_FSV_SIG_TRUE:
+	case IPE_PROP_BPF_SIG_NONE:
+	case IPE_PROP_BPF_SIG_OK:
+	case IPE_PROP_BPF_SIG_UNSIGNED:
+	case IPE_PROP_BPF_SIG_PARTIALSIG:
+	case IPE_PROP_BPF_SIG_UNKNOWNKEY:
+	case IPE_PROP_BPF_SIG_UNEXPECTED:
+	case IPE_PROP_BPF_SIG_FAULT:
+	case IPE_PROP_BPF_SIG_BADSIG:
+	case IPE_PROP_BPF_KEYRING_BUILTIN:
+	case IPE_PROP_BPF_KEYRING_SECONDARY:
+	case IPE_PROP_BPF_KEYRING_PLATFORM:
+	case IPE_PROP_BPF_KERNEL_FALSE:
+	case IPE_PROP_BPF_KERNEL_TRUE:
 		p->type = token;
 		break;
 	default:
-- 
2.53.0

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

[Fan Wu]

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