* [v6 00/10] Reintroduce Hornet LSM
From: Blaise Boscaccy @ 2026-04-29 19:14 UTC (permalink / raw)
To: Blaise Boscaccy, Jonathan Corbet, Paul Moore, James Morris,
Serge E. Hallyn, Mickaël Salaün, Günther Noack,
Dr. David Alan Gilbert, Andrew Morton, James.Bottomley, dhowells,
Fan Wu, Ryan Foster, Randy Dunlap, linux-security-module,
linux-doc, linux-kernel, bpf, Song Liu
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 V6:
- Doc cleanup
- Error handling improvements
- Support for shareable maps
Link to V5: https://lore.kernel.org/linux-security-module/20260420212653.438685-1-bboscaccy@linux.microsoft.com/
Changes in V5:
- Added IPE documentation
Link to V4: https://lore.kernel.org/linux-security-module/20260416173500.176716-1-bboscaccy@linux.microsoft.com/
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 | 323 +++++++++++++++
Documentation/admin-guide/LSM/index.rst | 1 +
Documentation/admin-guide/LSM/ipe.rst | 162 +++++++-
Documentation/security/ipe.rst | 39 ++
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 | 397 +++++++++++++++++++
scripts/hornet/write-sig.sh | 27 ++
security/Kconfig | 3 +-
security/Makefile | 1 +
security/hornet/Kconfig | 13 +
security/hornet/Makefile | 7 +
security/hornet/hornet.asn1 | 12 +
security/hornet/hornet_lsm.c | 350 ++++++++++++++++
security/ipe/Kconfig | 14 +
security/ipe/audit.c | 15 +
security/ipe/eval.c | 73 +++-
security/ipe/eval.h | 11 +
security/ipe/hooks.c | 63 +++
security/ipe/hooks.h | 15 +
security/ipe/ipe.c | 14 +
security/ipe/ipe.h | 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 ++
45 files changed, 2056 insertions(+), 8 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
^ permalink raw reply
* [v6 01/10] crypto: pkcs7: add flag for validated trust on a signed info block
From: Blaise Boscaccy @ 2026-04-29 19:14 UTC (permalink / raw)
To: Blaise Boscaccy, Jonathan Corbet, Paul Moore, James Morris,
Serge E. Hallyn, Mickaël Salaün, Günther Noack,
Dr. David Alan Gilbert, Andrew Morton, James.Bottomley, dhowells,
Fan Wu, Ryan Foster, Randy Dunlap, linux-security-module,
linux-doc, linux-kernel, bpf, Song Liu
In-Reply-To: <20260429191431.2345448-1-bboscaccy@linux.microsoft.com>
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
^ permalink raw reply related
* [v6 02/10] crypto: pkcs7: add ability to extract signed attributes by OID
From: Blaise Boscaccy @ 2026-04-29 19:14 UTC (permalink / raw)
To: Blaise Boscaccy, Jonathan Corbet, Paul Moore, James Morris,
Serge E. Hallyn, Mickaël Salaün, Günther Noack,
Dr. David Alan Gilbert, Andrew Morton, James.Bottomley, dhowells,
Fan Wu, Ryan Foster, Randy Dunlap, linux-security-module,
linux-doc, linux-kernel, bpf, Song Liu
In-Reply-To: <20260429191431.2345448-1-bboscaccy@linux.microsoft.com>
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
^ permalink raw reply related
* [v6 03/10] crypto: pkcs7: add tests for pkcs7_get_authattr
From: Blaise Boscaccy @ 2026-04-29 19:14 UTC (permalink / raw)
To: Blaise Boscaccy, Jonathan Corbet, Paul Moore, James Morris,
Serge E. Hallyn, Mickaël Salaün, Günther Noack,
Dr. David Alan Gilbert, Andrew Morton, James.Bottomley, dhowells,
Fan Wu, Ryan Foster, Randy Dunlap, linux-security-module,
linux-doc, linux-kernel, bpf, Song Liu
In-Reply-To: <20260429191431.2345448-1-bboscaccy@linux.microsoft.com>
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
^ permalink raw reply related
* [v6 04/10] lsm: framework for BPF integrity verification
From: Blaise Boscaccy @ 2026-04-29 19:14 UTC (permalink / raw)
To: Blaise Boscaccy, Jonathan Corbet, Paul Moore, James Morris,
Serge E. Hallyn, Mickaël Salaün, Günther Noack,
Dr. David Alan Gilbert, Andrew Morton, James.Bottomley, dhowells,
Fan Wu, Ryan Foster, Randy Dunlap, linux-security-module,
linux-doc, linux-kernel, bpf, Song Liu
In-Reply-To: <20260429191431.2345448-1-bboscaccy@linux.microsoft.com>
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
^ permalink raw reply related
* [v6 05/10] lsm: security: Add additional enum values for bpf integrity checks
From: Blaise Boscaccy @ 2026-04-29 19:14 UTC (permalink / raw)
To: Blaise Boscaccy, Jonathan Corbet, Paul Moore, James Morris,
Serge E. Hallyn, Mickaël Salaün, Günther Noack,
Dr. David Alan Gilbert, Andrew Morton, James.Bottomley, dhowells,
Fan Wu, Ryan Foster, Randy Dunlap, linux-security-module,
linux-doc, linux-kernel, bpf, Song Liu
In-Reply-To: <20260429191431.2345448-1-bboscaccy@linux.microsoft.com>
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
^ permalink raw reply related
* [v6 06/10] security: Hornet LSM
From: Blaise Boscaccy @ 2026-04-29 19:14 UTC (permalink / raw)
To: Blaise Boscaccy, Jonathan Corbet, Paul Moore, James Morris,
Serge E. Hallyn, Mickaël Salaün, Günther Noack,
Dr. David Alan Gilbert, Andrew Morton, James.Bottomley, dhowells,
Fan Wu, Ryan Foster, Randy Dunlap, linux-security-module,
linux-doc, linux-kernel, bpf, Song Liu
In-Reply-To: <20260429191431.2345448-1-bboscaccy@linux.microsoft.com>
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 | 323 +++++++++++++++++++++
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 | 13 +
security/hornet/Makefile | 7 +
security/hornet/hornet.asn1 | 12 +
security/hornet/hornet_lsm.c | 350 +++++++++++++++++++++++
11 files changed, 722 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..ef1605b162f57
--- /dev/null
+++ b/Documentation/admin-guide/LSM/Hornet.rst
@@ -0,0 +1,323 @@
+.. 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 whichever keyring was specified by the user
+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 keyring requested by the user is invalid.
+
+``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.
+
+- The only hashing algorithm available is SHA256 due to it be hardcoded
+ in the bpf subsystem.
+
+- Hornet guarantees that the signed program runs only with signed map
+ data. It does not guarantee positional binding of maps to specific
+ fd_array slots.
+
+- BPF_MAP_TYPE_PROG_ARRAY maps must be frozen for Hornet to verify
+ them. Unfrozen prog array maps are not covered by verification.
+
+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_message_sig()`` with the user specified 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-$(CONFIG_INTEGRITY) += integrity/
diff --git a/security/hornet/Kconfig b/security/hornet/Kconfig
new file mode 100644
index 0000000000000..5be71d97daee2
--- /dev/null
+++ b/security/hornet/Kconfig
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config SECURITY_HORNET
+ bool "Hornet support"
+ select CRYPTO_LIB_SHA256
+ select PKCS7_MESSAGE_PARSER
+ select SYSTEM_DATA_VERIFICATION
+ default n
+ help
+ This selects Hornet.
+ Further information can be found in
+ Documentation/admin-guide/LSM/Hornet.rst.
+
+ If you are unsure how to answer this question, answer N.
diff --git a/security/hornet/Makefile b/security/hornet/Makefile
new file mode 100644
index 0000000000000..26b6f954f762e
--- /dev/null
+++ b/security/hornet/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(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..e60abf451ae23
--- /dev/null
+++ b/security/hornet/hornet.asn1
@@ -0,0 +1,12 @@
+-- SPDX-License-Identifier: BSD-3-Clause
+--
+-- Copyright (C) 2026 Microsoft
+--
+-- 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..4656457657ccd
--- /dev/null
+++ b/security/hornet/hornet_lsm.c
@@ -0,0 +1,350 @@
+// 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 {
+ int signed_hash_count;
+ unsigned char signed_hashes[SHA256_DIGEST_SIZE * MAX_USED_MAPS];
+};
+
+struct lsm_blob_sizes hornet_blob_sizes __ro_after_init = {
+ .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 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);
+
+ 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;
+
+ if (!map->ops->map_get_hash)
+ return LSM_INT_VERDICT_FAULT;
+
+ if (map->ops->map_get_hash(map, SHA256_DIGEST_SIZE, hash))
+ return LSM_INT_VERDICT_FAULT;
+
+ err = memcmp(hash, &ctx->hashes[i * SHA256_DIGEST_SIZE],
+ SHA256_DIGEST_SIZE);
+ if (err)
+ return LSM_INT_VERDICT_UNEXPECTED;
+
+ memcpy(&security->signed_hashes[security->signed_hash_count * SHA256_DIGEST_SIZE],
+ &ctx->hashes[i * SHA256_DIGEST_SIZE], SHA256_DIGEST_SIZE);
+ security->signed_hash_count++;
+ }
+ 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;
+ key_ref_t user_key = ERR_PTR(-ENOKEY);
+
+ if (!attr->signature) {
+ *verdict = LSM_INT_VERDICT_UNSIGNED;
+ return 0;
+ }
+
+ if (!attr->signature_size) {
+ *verdict = LSM_INT_VERDICT_BADSIG;
+ 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) {
+ err = -EFAULT;
+ 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 {
+ user_key = lookup_user_key(attr->keyring_id, 0, KEY_DEFER_PERM_CHECK);
+ if (IS_ERR(user_key)) {
+ *verdict = LSM_INT_VERDICT_UNKNOWNKEY;
+ goto cleanup_msg;
+ }
+ key = key_ref_to_ptr(user_key);
+ }
+
+ if (verify_pkcs7_message_sig(prog->insnsi, prog->len * sizeof(struct bpf_insn), msg,
+ key,
+ VERIFYING_BPF_SIGNATURE,
+ NULL, NULL)) {
+ *verdict = LSM_INT_VERDICT_BADSIG;
+ 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;
+ }
+
+ *verdict = hornet_verify_hashes(&maps, ctx, prog);
+ err = 0;
+
+cleanup_msg:
+ pkcs7_free_message(msg);
+ if (!IS_ERR(user_key))
+ key_put(key);
+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_check_prog_maps(u32 ufd)
+{
+ CLASS(fd, f)(ufd);
+ struct bpf_prog *prog;
+ struct hornet_prog_security_struct *security;
+ unsigned char hash[SHA256_DIGEST_SIZE];
+ struct bpf_map *map;
+ int i, j;
+ bool found;
+ int covered_count = 0;
+
+ if (fd_empty(f))
+ return -EBADF;
+ if (fd_file(f)->f_op != &bpf_prog_fops)
+ return -EINVAL;
+
+ prog = fd_file(f)->private_data;
+ security = hornet_bpf_prog_security(prog);
+
+ if (!security->signed_hash_count)
+ return 0;
+
+ mutex_lock(&prog->aux->used_maps_mutex);
+
+ /* Verify every used_map has a matching signed hash */
+ for (j = 0; j < prog->aux->used_map_cnt; j++) {
+ map = prog->aux->used_maps[j];
+
+ if (!map->frozen || !map->ops->map_get_hash)
+ continue;
+
+ if (map->ops->map_get_hash(map, SHA256_DIGEST_SIZE, hash))
+ continue;
+
+ found = false;
+ for (i = 0; i < security->signed_hash_count; i++) {
+ if (memcmp(hash,
+ &security->signed_hashes[i * SHA256_DIGEST_SIZE],
+ SHA256_DIGEST_SIZE) == 0) {
+ found = true;
+ break;
+ }
+ }
+ if (!found) {
+ mutex_unlock(&prog->aux->used_maps_mutex);
+ return -EPERM;
+ }
+ covered_count++;
+ }
+
+ mutex_unlock(&prog->aux->used_maps_mutex);
+
+ /* Ensure all signed hashes were accounted for */
+ if (covered_count != security->signed_hash_count)
+ return -EPERM;
+
+ return 0;
+}
+
+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
^ permalink raw reply related
* [v6 07/10] hornet: Introduce gen_sig
From: Blaise Boscaccy @ 2026-04-29 19:14 UTC (permalink / raw)
To: Blaise Boscaccy, Jonathan Corbet, Paul Moore, James Morris,
Serge E. Hallyn, Mickaël Salaün, Günther Noack,
Dr. David Alan Gilbert, Andrew Morton, James.Bottomley, dhowells,
Fan Wu, Ryan Foster, Randy Dunlap, linux-security-module,
linux-doc, linux-kernel, bpf, Song Liu
In-Reply-To: <20260429191431.2345448-1-bboscaccy@linux.microsoft.com>
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 | 397 ++++++++++++++++++++++++++++++++++++
scripts/hornet/write-sig.sh | 27 +++
4 files changed, 430 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..8e328b4ca120a
--- /dev/null
+++ b/scripts/hornet/gen_sig.c
@@ -0,0 +1,397 @@
+/* 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);
+ if (++hash_count >= MAX_HASHES) {
+ usage(argv[0]);
+ return EXIT_FAILURE;
+ }
+ } 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++) {
+ if (sha256(hashes[i].file, hash_buffer, &hash_len) != 0) {
+ DIE("failed to hash input");
+ }
+ 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")"'\";' $1
+fi
--
2.53.0
^ permalink raw reply related
* [v6 08/10] hornet: Add a light skeleton data extractor scripts
From: Blaise Boscaccy @ 2026-04-29 19:14 UTC (permalink / raw)
To: Blaise Boscaccy, Jonathan Corbet, Paul Moore, James Morris,
Serge E. Hallyn, Mickaël Salaün, Günther Noack,
Dr. David Alan Gilbert, Andrew Morton, James.Bottomley, dhowells,
Fan Wu, Ryan Foster, Randy Dunlap, linux-security-module,
linux-doc, linux-kernel, bpf, Song Liu
In-Reply-To: <20260429191431.2345448-1-bboscaccy@linux.microsoft.com>
These script eases light skeleton development against Hornet by
generating a data payloads which can be used for signing a light
skeleton binary using gen_sig.
Signed-off-by: Blaise Boscaccy <bboscaccy@linux.microsoft.com>
---
| 27 +++++++++++++++++++++++++++
| 27 +++++++++++++++++++++++++++
| 27 +++++++++++++++++++++++++++
3 files changed, 81 insertions(+)
create mode 100755 scripts/hornet/extract-insn.sh
create mode 100755 scripts/hornet/extract-map.sh
create mode 100755 scripts/hornet/extract-skel.sh
--git a/scripts/hornet/extract-insn.sh b/scripts/hornet/extract-insn.sh
new file mode 100755
index 0000000000000..52338f057ff6b
--- /dev/null
+++ b/scripts/hornet/extract-insn.sh
@@ -0,0 +1,27 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (c) 2025 Microsoft Corporation
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of version 2 of the GNU General Public
+# License as published by the Free Software Foundation.
+
+function usage() {
+ echo "Sample script for extracting instructions"
+ echo "autogenerated eBPF lskel headers"
+ echo ""
+ echo "USAGE: header_file"
+ exit
+}
+
+ARGC=$#
+
+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
--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
--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
^ permalink raw reply related
* [v6 09/10] selftests/hornet: Add a selftest for the Hornet LSM
From: Blaise Boscaccy @ 2026-04-29 19:14 UTC (permalink / raw)
To: Blaise Boscaccy, Jonathan Corbet, Paul Moore, James Morris,
Serge E. Hallyn, Mickaël Salaün, Günther Noack,
Dr. David Alan Gilbert, Andrew Morton, James.Bottomley, dhowells,
Fan Wu, Ryan Foster, Randy Dunlap, linux-security-module,
linux-doc, linux-kernel, bpf, Song Liu
In-Reply-To: <20260429191431.2345448-1-bboscaccy@linux.microsoft.com>
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
^ permalink raw reply related
* [v6 10/10] ipe: Add BPF program load policy enforcement via Hornet integration
From: Blaise Boscaccy @ 2026-04-29 19:14 UTC (permalink / raw)
To: Blaise Boscaccy, Jonathan Corbet, Paul Moore, James Morris,
Serge E. Hallyn, Mickaël Salaün, Günther Noack,
Dr. David Alan Gilbert, Andrew Morton, James.Bottomley, dhowells,
Fan Wu, Ryan Foster, Randy Dunlap, linux-security-module,
linux-doc, linux-kernel, bpf, Song Liu
In-Reply-To: <20260429191431.2345448-1-bboscaccy@linux.microsoft.com>
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.
Signed-off-by: Blaise Boscaccy <bboscaccy@linux.microsoft.com>
---
Documentation/admin-guide/LSM/ipe.rst | 162 +++++++++++++++++++++++++-
Documentation/security/ipe.rst | 39 +++++++
security/ipe/Kconfig | 14 +++
security/ipe/audit.c | 15 +++
security/ipe/eval.c | 73 +++++++++++-
security/ipe/eval.h | 11 ++
security/ipe/hooks.c | 63 ++++++++++
security/ipe/hooks.h | 15 +++
security/ipe/ipe.c | 14 +++
security/ipe/ipe.h | 3 +
security/ipe/policy.h | 14 +++
security/ipe/policy_parser.c | 27 +++++
12 files changed, 448 insertions(+), 2 deletions(-)
diff --git a/Documentation/admin-guide/LSM/ipe.rst b/Documentation/admin-guide/LSM/ipe.rst
index a756d81585317..4dfbf0d325a8a 100644
--- a/Documentation/admin-guide/LSM/ipe.rst
+++ b/Documentation/admin-guide/LSM/ipe.rst
@@ -559,7 +559,8 @@ policy. Two properties are built-into the policy parser: 'op' and 'action'.
The other properties are used to restrict immutable security properties
about the files being evaluated. Currently those properties are:
'``boot_verified``', '``dmverity_signature``', '``dmverity_roothash``',
-'``fsverity_signature``', '``fsverity_digest``'. A description of all
+'``fsverity_signature``', '``fsverity_digest``', '``bpf_signature``',
+'``bpf_keyring``', '``bpf_kernel``'. A description of all
properties supported by IPE are listed below:
op
@@ -603,6 +604,14 @@ as the first token. IPE supports the following operations:
Controls loading IMA certificates through the Kconfigs,
``CONFIG_IMA_X509_PATH`` and ``CONFIG_EVM_X509_PATH``.
+ ``BPF_PROG_LOAD``:
+
+ Pertains to BPF programs being loaded via the ``bpf()`` syscall.
+ This operation is used in conjunction with the ``bpf_signature``,
+ ``bpf_keyring``, and ``bpf_kernel`` properties to control BPF
+ program loading based on integrity verification provided by the
+ Hornet LSM.
+
action
~~~~~~
@@ -713,6 +722,105 @@ fsverity_signature
fsverity_signature=(TRUE|FALSE)
+bpf_signature
+~~~~~~~~~~~~~
+
+ This property can be utilized for authorization of BPF program loads based
+ on the integrity verdict provided by the Hornet LSM. When a BPF program is
+ loaded, Hornet performs cryptographic verification of the program's PKCS#7
+ signature (if present) and passes an integrity verdict to IPE via the
+ ``security_bpf_prog_load_post_integrity`` hook. IPE can then allow or deny
+ the load based on the verdict.
+
+ This property depends on ``SECURITY_HORNET`` and is controlled by the
+ ``IPE_PROP_BPF_SIGNATURE`` config option.
+ The format of this property is::
+
+ bpf_signature=(NONE|OK|UNSIGNED|PARTIALSIG|UNKNOWNKEY|UNEXPECTED|FAULT|BADSIG)
+
+ The possible values correspond to the integrity verdicts from Hornet:
+
+ ``NONE``
+
+ No integrity verdict was set (default/uninitialized).
+
+ ``OK``
+
+ The BPF program's signature and all map hashes were successfully
+ verified.
+
+ ``UNSIGNED``
+
+ No signature was provided with the BPF program.
+
+ ``PARTIALSIG``
+
+ The program signature was verified, but no authenticated map hash
+ data was present.
+
+ ``UNKNOWNKEY``
+
+ The signing certificate is not trusted by the specified keyring.
+
+ ``UNEXPECTED``
+
+ An unexpected map hash value was encountered during verification.
+
+ ``FAULT``
+
+ A system error occurred during signature verification.
+
+ ``BADSIG``
+
+ The signature or hash verification failed.
+
+bpf_keyring
+~~~~~~~~~~~~
+
+ This property can be utilized for authorization of BPF program loads based
+ on the keyring specified in the ``bpf_attr`` during the ``BPF_PROG_LOAD``
+ syscall. This allows policies to restrict which keyring must be used for
+ signature verification of BPF programs.
+
+ This property shares the ``IPE_PROP_BPF_SIGNATURE`` config option with
+ ``bpf_signature``.
+ The format of this property is::
+
+ bpf_keyring=(BUILTIN|SECONDARY|PLATFORM)
+
+ The possible values correspond to the system keyrings:
+
+ ``BUILTIN``
+
+ The builtin trusted keyring (``.builtin_trusted_keys``), which
+ contains keys embedded at kernel compile time.
+
+ ``SECONDARY``
+
+ The secondary trusted keyring (``.secondary_trusted_keys``), which
+ includes both builtin trusted keys and keys added at runtime.
+
+ ``PLATFORM``
+
+ The platform keyring (``.platform``), which contains keys provided
+ by the platform firmware (e.g. UEFI db keys).
+
+bpf_kernel
+~~~~~~~~~~
+
+ This property can be utilized for authorization of BPF program loads based
+ on whether the load originated from kernel space or user space. The BPF
+ light skeleton infrastructure performs a secondary kernel-originated program
+ load that will not carry a signature. This property allows policies to
+ permit such kernel-originated loads while still requiring signatures for
+ user-space loads.
+
+ This property shares the ``IPE_PROP_BPF_SIGNATURE`` config option with
+ ``bpf_signature``.
+ The format of this property is::
+
+ bpf_kernel=(TRUE|FALSE)
+
Policy Examples
---------------
@@ -788,6 +896,58 @@ Allow execution of a specific fs-verity file
op=EXECUTE fsverity_digest=sha256:fd88f2b8824e197f850bf4c5109bea5cf0ee38104f710843bb72da796ba5af9e action=ALLOW
+Allow only signed BPF programs
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+::
+
+ policy_name=Allow_Signed_BPF policy_version=0.0.0
+ DEFAULT action=ALLOW
+
+ DEFAULT op=BPF_PROG_LOAD action=DENY
+ op=BPF_PROG_LOAD bpf_kernel=TRUE action=ALLOW
+ op=BPF_PROG_LOAD bpf_signature=OK action=ALLOW
+
+This policy allows all other operations but restricts BPF program loading
+to only programs that either originate from kernel space (e.g. light skeleton
+reloads) or have a valid signature verified by the Hornet LSM. Unsigned or
+improperly signed BPF programs from user space will be denied.
+
+Allow signed BPF programs from a specific keyring
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+::
+
+ policy_name=Allow_BPF_Builtin_Keyring policy_version=0.0.0
+ DEFAULT action=ALLOW
+
+ DEFAULT op=BPF_PROG_LOAD action=DENY
+ op=BPF_PROG_LOAD bpf_kernel=TRUE action=ALLOW
+ op=BPF_PROG_LOAD bpf_signature=OK bpf_keyring=BUILTIN action=ALLOW
+
+This policy further restricts BPF program loading to only accept programs
+whose signatures were verified using the builtin trusted keyring. Programs
+signed against the secondary or platform keyrings will be denied, providing
+tighter control over which signing keys are acceptable.
+
+Allow signed BPF programs with relaxed partial signatures
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+::
+
+ policy_name=Allow_BPF_Partial policy_version=0.0.0
+ DEFAULT action=ALLOW
+
+ DEFAULT op=BPF_PROG_LOAD action=DENY
+ op=BPF_PROG_LOAD bpf_kernel=TRUE action=ALLOW
+ op=BPF_PROG_LOAD bpf_signature=OK action=ALLOW
+ op=BPF_PROG_LOAD bpf_signature=PARTIALSIG action=ALLOW
+
+This policy allows BPF programs that have been fully verified (``OK``) as
+well as programs with a valid program signature but without authenticated
+map hash data (``PARTIALSIG``). This can be useful during development or
+for programs that do not use maps.
+
Additional Information
----------------------
diff --git a/Documentation/security/ipe.rst b/Documentation/security/ipe.rst
index 4a7d953abcdc3..de8fcf1dc173d 100644
--- a/Documentation/security/ipe.rst
+++ b/Documentation/security/ipe.rst
@@ -412,6 +412,44 @@ a standard securityfs policy tree::
The policy is stored in the ``->i_private`` data of the MyPolicy inode.
+BPF/Hornet Integration
+~~~~~~~~~~~~~~~~~~~~~~
+
+IPE integrates with the Hornet LSM to enforce integrity policies on BPF
+program loading. Hornet performs cryptographic verification of BPF program
+signatures (PKCS#7 with authenticated attributes containing map hashes) and
+provides an integrity verdict to IPE via the
+``security_bpf_prog_load_post_integrity`` hook.
+
+The hook flow is:
+
+ 1. User space invokes ``BPF_PROG_LOAD`` via the ``bpf()`` syscall.
+ 2. Hornet's ``bpf_prog_load_integrity`` hook calls ``hornet_check_program()``
+ to verify the program's signature and map hashes.
+ 3. Hornet calls ``security_bpf_prog_load_post_integrity()`` with the
+ resulting ``lsm_integrity_verdict``.
+ 4. IPE evaluates the verdict against the active policy's ``BPF_PROG_LOAD``
+ rules and returns ``-EACCES`` if denied.
+
+Three properties are available for BPF policy rules:
+
+ - ``bpf_signature``: Matches against the integrity verdict (OK, UNSIGNED,
+ BADSIG, etc.)
+ - ``bpf_keyring``: Matches against the keyring specified in ``bpf_attr``
+ (BUILTIN, SECONDARY, PLATFORM)
+ - ``bpf_kernel``: Matches whether the load originated from kernel space
+ (TRUE/FALSE). This is important because the BPF light skeleton
+ infrastructure performs a secondary kernel-originated program load that
+ does not carry a signature.
+
+All three properties are gated on ``CONFIG_IPE_PROP_BPF_SIGNATURE`` which
+depends on ``CONFIG_SECURITY_HORNET``.
+
+The evaluation context (``struct ipe_eval_ctx``) carries three BPF-specific
+fields: ``bpf_verdict`` (the integrity verdict enum), ``bpf_keyring_id``
+(the ``s32`` keyring ID from ``bpf_attr``), and ``bpf_kernel`` (bool
+indicating kernel origin).
+
Tests
-----
@@ -439,6 +477,7 @@ IPE has KUnit Tests for the policy parser. Recommended kunitconfig::
CONFIG_IPE_PROP_DM_VERITY_SIGNATURE=y
CONFIG_IPE_PROP_FS_VERITY=y
CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG=y
+ CONFIG_IPE_PROP_BPF_SIGNATURE=y
CONFIG_SECURITY_IPE_KUNIT_TEST=y
In addition, IPE has a python based integration
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..b061cb5ade27e 100644
--- a/security/ipe/eval.h
+++ b/security/ipe/eval.h
@@ -37,6 +37,12 @@ struct ipe_inode {
};
#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
+#ifdef CONFIG_IPE_PROP_BPF_SIGNATURE
+struct ipe_bpf_prog {
+ enum lsm_integrity_verdict verdict;
+};
+#endif /* CONFIG_IPE_PROP_BPF_SIGNATURE */
+
struct ipe_eval_ctx {
enum ipe_op_type op;
enum ipe_hook_type hook;
@@ -52,6 +58,11 @@ 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..9271e129a2cf2 100644
--- a/security/ipe/hooks.c
+++ b/security/ipe/hooks.c
@@ -340,3 +340,66 @@ 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() - Store integrity verdict in per-prog blob.
+ * @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 hook stores the integrity verdict in IPE's per-prog security blob
+ * so that ipe_bpf_prog_load() can later read it for policy evaluation.
+ *
+ * Return:
+ * * %0 - Always succeeds (policy is evaluated in bpf_prog_load)
+ */
+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_bpf_prog *blob = ipe_bpf_prog(prog);
+
+ blob->verdict = verdict;
+
+ return 0;
+}
+
+/**
+ * ipe_bpf_prog_load() - IPE policy evaluation 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.
+ *
+ * Reads the integrity verdict previously stored by post_integrity (if any)
+ * and evaluates IPE policy. If no integrity provider ran, the verdict
+ * defaults to LSM_INT_VERDICT_NONE.
+ *
+ * Return:
+ * * %0 - Success
+ * * %-EACCES - Did not pass IPE policy
+ */
+int ipe_bpf_prog_load(struct bpf_prog *prog,
+ union bpf_attr *attr,
+ struct bpf_token *token,
+ bool kernel)
+{
+ struct ipe_bpf_prog *blob = ipe_bpf_prog(prog);
+ 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 = blob->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..8a6d1a459e00c 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 +54,17 @@ 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);
+int ipe_bpf_prog_load(struct bpf_prog *prog,
+ union bpf_attr *attr,
+ struct bpf_token *token,
+ bool kernel);
+#endif /* CONFIG_IPE_PROP_BPF_SIGNATURE */
+
#endif /* _IPE_HOOKS_H */
diff --git a/security/ipe/ipe.c b/security/ipe/ipe.c
index 495bb765de1b8..5af13903287fe 100644
--- a/security/ipe/ipe.c
+++ b/security/ipe/ipe.c
@@ -19,6 +19,9 @@ static struct lsm_blob_sizes ipe_blobs __ro_after_init = {
#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG
.lbs_inode = sizeof(struct ipe_inode),
#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
+#ifdef CONFIG_IPE_PROP_BPF_SIGNATURE
+ .lbs_bpf_prog = sizeof(struct ipe_bpf_prog),
+#endif /* CONFIG_IPE_PROP_BPF_SIGNATURE */
};
static const struct lsm_id ipe_lsmid = {
@@ -45,6 +48,13 @@ struct ipe_inode *ipe_inode(const struct inode *inode)
}
#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
+#ifdef CONFIG_IPE_PROP_BPF_SIGNATURE
+struct ipe_bpf_prog *ipe_bpf_prog(const struct bpf_prog *prog)
+{
+ return prog->aux->security + ipe_blobs.lbs_bpf_prog;
+}
+#endif /* CONFIG_IPE_PROP_BPF_SIGNATURE */
+
static struct security_hook_list ipe_hooks[] __ro_after_init = {
LSM_HOOK_INIT(bprm_check_security, ipe_bprm_check_security),
LSM_HOOK_INIT(bprm_creds_for_exec, ipe_bprm_creds_for_exec),
@@ -60,6 +70,10 @@ 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),
+ LSM_HOOK_INIT(bpf_prog_load, ipe_bpf_prog_load),
+#endif /* CONFIG_IPE_PROP_BPF_SIGNATURE */
};
/**
diff --git a/security/ipe/ipe.h b/security/ipe/ipe.h
index 25cfdb8f0c20a..47de32b5bc938 100644
--- a/security/ipe/ipe.h
+++ b/security/ipe/ipe.h
@@ -22,6 +22,9 @@ struct ipe_bdev *ipe_bdev(struct block_device *b);
#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG
struct ipe_inode *ipe_inode(const struct inode *inode);
#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
+#ifdef CONFIG_IPE_PROP_BPF_SIGNATURE
+struct ipe_bpf_prog *ipe_bpf_prog(const struct bpf_prog *prog);
+#endif /* CONFIG_IPE_PROP_BPF_SIGNATURE */
int ipe_init_securityfs(void);
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
^ permalink raw reply related
* [PATCH] ima: debugging late_initcall_sync measurements
From: Mimi Zohar @ 2026-04-29 20:01 UTC (permalink / raw)
To: Jonathan McDowell, linux-security-module, linux-kernel,
linux-integrity, linux-arm-kernel, kvmarm
Cc: paul, jmorris, serge, roberto.sassu, dmitry.kasatkin,
eric.snowberg, jarkko, jgg, sudeep.holla, maz, oupton, joey.gouly,
suzuki.poulose, yuzenghui, catalin.marinas, will, noodles,
sebastianene, Yeoreum Yun
In-Reply-To: <cover.1777036497.git.noodles@meta.com>
With this "[RFC PATCH v3 0/4] Fix IMA + TPM initialisation ordering
issue" patch set, how many records would be missing if IMA
initialization is deferred to late_initcall_sync [1]?
[1]https://lore.kernel.org/linux-integrity/cover.1777036497.git.noodles@meta.com/
---
Jonathan, Yeoreum, others -
By going into TPM-bypass mode, we can see how many measurements are actually
missing when deferring IMA initialization to late_initcall_sync. As this is
system/TPM dependent, I'd appreciate your checking. Please use the boot command
line option "ima_policy=tcb|critical_data".
thanks, Mimi
security/integrity/ima/ima.h | 1 +
security/integrity/ima/ima_init.c | 6 ++++++
security/integrity/ima/ima_main.c | 19 +++++++++++++++++++
3 files changed, 26 insertions(+)
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 01aae19ed365..9a1117112fb2 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -286,6 +286,7 @@ extern bool ima_canonical_fmt;
/* Internal IMA function definitions */
int ima_init_core(bool late);
+int ima_init_debug(bool late);
int ima_fs_init(void);
int ima_add_template_entry(struct ima_template_entry *entry, int violation,
const char *op, struct inode *inode,
diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
index 5f335834a9bb..edd063b99685 100644
--- a/security/integrity/ima/ima_init.c
+++ b/security/integrity/ima/ima_init.c
@@ -122,6 +122,12 @@ void __init ima_load_x509(void)
}
#endif
+int __init ima_init_debug(bool late)
+{
+ ima_add_boot_aggregate(late); /* just add an additional record */
+ return 0;
+}
+
int __init ima_init_core(bool late)
{
int rc;
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 42099bfe7e43..23e669be54fc 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -1254,6 +1254,7 @@ static int ima_kernel_module_request(char *kmod_name)
#endif /* CONFIG_INTEGRITY_ASYMMETRIC_KEYS */
+#define TESTING 1
static int __init init_ima(bool late)
{
int error;
@@ -1264,6 +1265,23 @@ static int __init init_ima(bool late)
return 0;
}
+#ifdef TESTING
+ /*
+ * Initialize early, even if it means going into TPM-bypass mode,
+ * but add an additional boot_aggregrate message for the
+ * late_initcall_sync.
+ *
+ * If measurement list records exist between the boot_aggregate
+ * and the boot_aggregate_late records, these records would be
+ * missing when IMA initializion is deferred to late_initcall_sync.
+ */
+ if (ima_tpm_chip) {
+ ima_init_debug(late); /* Add an additional record */
+ return 0;
+ }
+
+ ima_tpm_chip = tpm_default_chip();
+#elif
/*
* If we found the TPM during our first attempt, or we know there's no
* TPM, nothing further to do
@@ -1276,6 +1294,7 @@ static int __init init_ima(bool late)
pr_debug("TPM not available, will try later\n");
return -EPROBE_DEFER;
}
+#endif
if (!ima_tpm_chip)
pr_info("No TPM chip found, activating TPM-bypass!\n");
--
2.53.0
^ permalink raw reply related
* [PATCH v2 0/7] lsm: Replace security_sb_mount with granular mount hooks
From: Song Liu @ 2026-04-30 0:03 UTC (permalink / raw)
To: linux-security-module, linux-fsdevel, selinux, apparmor
Cc: paul, jmorris, serge, viro, brauner, jack, john.johansen,
stephen.smalley.work, omosnace, mic, gnoack, takedakn,
penguin-kernel, herton, kernel-team, Song Liu
This series replaces the monolithic security_sb_mount() hook with
per-operation mount hooks, addressing two main issues:
1. TOCTOU: security_sb_mount() receives dev_name as a string, which
LSMs like AppArmor and Tomoyo re-resolve via kern_path(). The new
hooks pass pre-resolved struct path pointers where possible (bind
mount, move mount), eliminating the double-resolution.
2. Conflation: security_sb_mount() handles bind, new mount, remount,
move, propagation changes, and mount reconfiguration through a
single hook, requiring LSMs to dispatch on flags internally. The
new hooks are called at the operation level with appropriate
context.
The new hooks are:
mount_bind - bind mount (pre-resolved source path)
mount_new - new filesystem mount (with fs_context)
mount_remount - filesystem remount (with fs_context)
mount_reconfigure - mount flag reconfiguration (MS_REMOUNT|MS_BIND)
mount_move - move mount (pre-resolved paths)
mount_change_type - propagation type changes
mount_new and mount_remount are called after parse_monolithic_mount_data(),
so LSMs have access to the fs_context with parsed mount options. They also
receive the original mount(2) flags and data pointer for LSMs (AppArmor,
Tomoyo) that need them for policy matching.
The series also replaces security_move_mount() with the new mount_move
hook, unifying the old mount(2) MS_MOVE path with the move_mount(2)
syscall path.
All existing LSM behaviors are preserved:
AppArmor: same policy matching, TOCTOU fixed for bind/move
SELinux: same permission checks (FILE__MOUNTON, FILESYSTEM__REMOUNT)
Landlock: same deny-all for sandboxed processes
Tomoyo: same policy matching, TOCTOU fixed for bind/move, unused
data_page parameter removed
This work is inspired by earlier discussions:
[1] https://lore.kernel.org/bpf/20251127005011.1872209-1-song@kernel.org/
[2] https://lore.kernel.org/linux-security-module/20250708230504.3994335-1-song@kernel.org/
Changes v1 => v2:
1. Rebase.
2. Add Reviewed-by and Tested-by from Stephen Smalley.
v1: https://lore.kernel.org/linux-security-module/20260318184400.3502908-1-song@kernel.org/
Song Liu (7):
lsm: Add granular mount hooks to replace security_sb_mount
apparmor: Remove redundant MS_MGC_MSK stripping in apparmor_sb_mount
apparmor: Convert from sb_mount to granular mount hooks
selinux: Convert from sb_mount to granular mount hooks
landlock: Convert from sb_mount to granular mount hooks
tomoyo: Convert from sb_mount to granular mount hooks
lsm: Remove security_sb_mount and security_move_mount
fs/namespace.c | 41 +++++++---
include/linux/lsm_hook_defs.h | 14 +++-
include/linux/security.h | 56 +++++++++++---
kernel/bpf/bpf_lsm.c | 7 +-
security/apparmor/include/mount.h | 5 +-
security/apparmor/lsm.c | 102 ++++++++++++++++++-------
security/apparmor/mount.c | 37 ++--------
security/landlock/fs.c | 41 ++++++++--
security/security.c | 119 +++++++++++++++++++++++-------
security/selinux/hooks.c | 49 ++++++++----
security/tomoyo/common.h | 2 +-
security/tomoyo/mount.c | 31 +++++---
security/tomoyo/tomoyo.c | 63 ++++++++++++----
13 files changed, 406 insertions(+), 161 deletions(-)
--
2.52.0
^ permalink raw reply
* [PATCH v2 1/7] lsm: Add granular mount hooks to replace security_sb_mount
From: Song Liu @ 2026-04-30 0:03 UTC (permalink / raw)
To: linux-security-module, linux-fsdevel, selinux, apparmor
Cc: paul, jmorris, serge, viro, brauner, jack, john.johansen,
stephen.smalley.work, omosnace, mic, gnoack, takedakn,
penguin-kernel, herton, kernel-team, Song Liu
In-Reply-To: <20260430000315.918964-1-song@kernel.org>
Add six new LSM hooks for mount operations:
- mount_bind(from, to, recurse): bind mount with pre-resolved
struct path for source and destination.
- mount_new(fc, mp, mnt_flags, flags, data): new mount, called after
mount options are parsed. The flags and data parameters carry the
original mount(2) flags and data for LSMs that need them (AppArmor,
Tomoyo).
- mount_remount(fc, mp, mnt_flags, flags, data): filesystem remount,
called after mount options are parsed into the fs_context.
- mount_reconfigure(mp, mnt_flags, flags): mount flag reconfiguration
(MS_REMOUNT|MS_BIND path).
- mount_move(from, to): move mount with pre-resolved paths.
- mount_change_type(mp, ms_flags): propagation type changes.
These replace the monolithic security_sb_mount() which conflates
multiple distinct operations into a single hook, and suffers from
TOCTOU issues where LSMs re-resolve string-based dev_name via
kern_path().
The mount_move hook is added alongside the existing move_mount hook.
During the transition, LSMs register for both hooks. The move_mount
hook will be removed once all LSMs have been converted.
Some LSMs, such as apparmor and tomoyo, audit the original input passed
in the mount syscall. To keep the same behavior, argument data and flags
are passed in do_* functions. These can be removed if these LSMs no
longer need these information.
All new hooks are registered as sleepable BPF LSM hooks.
Code generated with the assistance of Claude, reviewed by human.
Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Tested-by: Stephen Smalley <stephen.smalley.work@gmail.com> # for selinux only
Signed-off-by: Song Liu <song@kernel.org>
---
fs/namespace.c | 35 ++++++++++--
include/linux/lsm_hook_defs.h | 12 ++++
include/linux/security.h | 50 +++++++++++++++++
kernel/bpf/bpf_lsm.c | 7 +++
security/security.c | 101 ++++++++++++++++++++++++++++++++++
5 files changed, 199 insertions(+), 6 deletions(-)
diff --git a/fs/namespace.c b/fs/namespace.c
index fe919abd2f01..e263319fb333 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -2888,6 +2888,10 @@ static int do_change_type(const struct path *path, int ms_flags)
if (!type)
return -EINVAL;
+ err = security_mount_change_type(path, ms_flags);
+ if (err)
+ return err;
+
guard(namespace_excl)();
err = may_change_propagation(mnt);
@@ -3006,6 +3010,10 @@ static int do_loopback(const struct path *path, const char *old_name,
if (err)
return err;
+ err = security_mount_bind(&old_path, path, recurse);
+ if (err)
+ return err;
+
if (mnt_ns_loop(old_path.dentry))
return -EINVAL;
@@ -3328,7 +3336,8 @@ static void mnt_warn_timestamp_expiry(const struct path *mountpoint,
* superblock it refers to. This is triggered by specifying MS_REMOUNT|MS_BIND
* to mount(2).
*/
-static int do_reconfigure_mnt(const struct path *path, unsigned int mnt_flags)
+static int do_reconfigure_mnt(const struct path *path, unsigned int mnt_flags,
+ unsigned long flags)
{
struct super_block *sb = path->mnt->mnt_sb;
struct mount *mnt = real_mount(path->mnt);
@@ -3343,6 +3352,10 @@ static int do_reconfigure_mnt(const struct path *path, unsigned int mnt_flags)
if (!can_change_locked_flags(mnt, mnt_flags))
return -EPERM;
+ ret = security_mount_reconfigure(path, mnt_flags, flags);
+ if (ret)
+ return ret;
+
/*
* We're only checking whether the superblock is read-only not
* changing it, so only take down_read(&sb->s_umount).
@@ -3366,7 +3379,7 @@ static int do_reconfigure_mnt(const struct path *path, unsigned int mnt_flags)
* on it - tough luck.
*/
static int do_remount(const struct path *path, int sb_flags,
- int mnt_flags, void *data)
+ int mnt_flags, void *data, unsigned long flags)
{
int err;
struct super_block *sb = path->mnt->mnt_sb;
@@ -3393,6 +3406,9 @@ static int do_remount(const struct path *path, int sb_flags,
fc->oldapi = true;
err = parse_monolithic_mount_data(fc, data);
+ if (!err)
+ err = security_mount_remount(fc, path, mnt_flags, flags,
+ data);
if (!err) {
down_write(&sb->s_umount);
err = -EPERM;
@@ -3708,6 +3724,10 @@ static int do_move_mount_old(const struct path *path, const char *old_name)
if (err)
return err;
+ err = security_mount_move(&old_path, path);
+ if (err)
+ return err;
+
return do_move_mount(&old_path, path, 0);
}
@@ -3786,7 +3806,7 @@ static int do_new_mount_fc(struct fs_context *fc, const struct path *mountpoint,
*/
static int do_new_mount(const struct path *path, const char *fstype,
int sb_flags, int mnt_flags,
- const char *name, void *data)
+ const char *name, void *data, unsigned long flags)
{
struct file_system_type *type;
struct fs_context *fc;
@@ -3830,6 +3850,9 @@ static int do_new_mount(const struct path *path, const char *fstype,
err = parse_monolithic_mount_data(fc, data);
if (!err && !mount_capable(fc))
err = -EPERM;
+
+ if (!err)
+ err = security_mount_new(fc, path, mnt_flags, flags, data);
if (!err)
err = do_new_mount_fc(fc, path, mnt_flags);
@@ -4141,9 +4164,9 @@ int path_mount(const char *dev_name, const struct path *path,
SB_I_VERSION);
if ((flags & (MS_REMOUNT | MS_BIND)) == (MS_REMOUNT | MS_BIND))
- return do_reconfigure_mnt(path, mnt_flags);
+ return do_reconfigure_mnt(path, mnt_flags, flags);
if (flags & MS_REMOUNT)
- return do_remount(path, sb_flags, mnt_flags, data_page);
+ return do_remount(path, sb_flags, mnt_flags, data_page, flags);
if (flags & MS_BIND)
return do_loopback(path, dev_name, flags & MS_REC);
if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE))
@@ -4152,7 +4175,7 @@ int path_mount(const char *dev_name, const struct path *path,
return do_move_mount_old(path, dev_name);
return do_new_mount(path, type_page, sb_flags, mnt_flags, dev_name,
- data_page);
+ data_page, flags);
}
int do_mount(const char *dev_name, const char __user *dir_name,
diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index 2b8dfb35caed..98f0fe382665 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -81,6 +81,18 @@ LSM_HOOK(int, 0, sb_clone_mnt_opts, const struct super_block *oldsb,
unsigned long *set_kern_flags)
LSM_HOOK(int, 0, move_mount, const struct path *from_path,
const struct path *to_path)
+LSM_HOOK(int, 0, mount_bind, const struct path *from, const struct path *to,
+ bool recurse)
+LSM_HOOK(int, 0, mount_new, struct fs_context *fc, const struct path *mp,
+ int mnt_flags, unsigned long flags, void *data)
+LSM_HOOK(int, 0, mount_remount, struct fs_context *fc,
+ const struct path *mp, int mnt_flags, unsigned long flags,
+ void *data)
+LSM_HOOK(int, 0, mount_reconfigure, const struct path *mp,
+ unsigned int mnt_flags, unsigned long flags)
+LSM_HOOK(int, 0, mount_move, const struct path *from_path,
+ const struct path *to_path)
+LSM_HOOK(int, 0, mount_change_type, const struct path *mp, int ms_flags)
LSM_HOOK(int, -EOPNOTSUPP, dentry_init_security, struct dentry *dentry,
int mode, const struct qstr *name, const char **xattr_name,
struct lsm_context *cp)
diff --git a/include/linux/security.h b/include/linux/security.h
index 41d7367cf403..b1b3da51a88d 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -386,6 +386,17 @@ int security_sb_clone_mnt_opts(const struct super_block *oldsb,
unsigned long kern_flags,
unsigned long *set_kern_flags);
int security_move_mount(const struct path *from_path, const struct path *to_path);
+int security_mount_bind(const struct path *from, const struct path *to,
+ bool recurse);
+int security_mount_new(struct fs_context *fc, const struct path *mp,
+ int mnt_flags, unsigned long flags, void *data);
+int security_mount_remount(struct fs_context *fc, const struct path *mp,
+ int mnt_flags, unsigned long flags, void *data);
+int security_mount_reconfigure(const struct path *mp, unsigned int mnt_flags,
+ unsigned long flags);
+int security_mount_move(const struct path *from_path,
+ const struct path *to_path);
+int security_mount_change_type(const struct path *mp, int ms_flags);
int security_dentry_init_security(struct dentry *dentry, int mode,
const struct qstr *name,
const char **xattr_name,
@@ -854,6 +865,45 @@ static inline int security_move_mount(const struct path *from_path,
return 0;
}
+static inline int security_mount_bind(const struct path *from,
+ const struct path *to, bool recurse)
+{
+ return 0;
+}
+
+static inline int security_mount_new(struct fs_context *fc,
+ const struct path *mp, int mnt_flags,
+ unsigned long flags, void *data)
+{
+ return 0;
+}
+
+static inline int security_mount_remount(struct fs_context *fc,
+ const struct path *mp, int mnt_flags,
+ unsigned long flags, void *data)
+{
+ return 0;
+}
+
+static inline int security_mount_reconfigure(const struct path *mp,
+ unsigned int mnt_flags,
+ unsigned long flags)
+{
+ return 0;
+}
+
+static inline int security_mount_move(const struct path *from_path,
+ const struct path *to_path)
+{
+ return 0;
+}
+
+static inline int security_mount_change_type(const struct path *mp,
+ int ms_flags)
+{
+ return 0;
+}
+
static inline int security_path_notify(const struct path *path, u64 mask,
unsigned int obj_type)
{
diff --git a/kernel/bpf/bpf_lsm.c b/kernel/bpf/bpf_lsm.c
index c5c925f00202..aa228372cfb4 100644
--- a/kernel/bpf/bpf_lsm.c
+++ b/kernel/bpf/bpf_lsm.c
@@ -382,6 +382,13 @@ BTF_ID(func, bpf_lsm_task_setscheduler)
BTF_ID(func, bpf_lsm_userns_create)
BTF_ID(func, bpf_lsm_bdev_alloc_security)
BTF_ID(func, bpf_lsm_bdev_setintegrity)
+BTF_ID(func, bpf_lsm_move_mount)
+BTF_ID(func, bpf_lsm_mount_bind)
+BTF_ID(func, bpf_lsm_mount_new)
+BTF_ID(func, bpf_lsm_mount_remount)
+BTF_ID(func, bpf_lsm_mount_reconfigure)
+BTF_ID(func, bpf_lsm_mount_move)
+BTF_ID(func, bpf_lsm_mount_change_type)
BTF_SET_END(sleepable_lsm_hooks)
BTF_SET_START(untrusted_lsm_hooks)
diff --git a/security/security.c b/security/security.c
index 4e999f023651..b7ec0ec7af26 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1182,6 +1182,107 @@ int security_move_mount(const struct path *from_path,
return call_int_hook(move_mount, from_path, to_path);
}
+/**
+ * security_mount_bind() - Check permissions for a bind mount
+ * @from: source path
+ * @to: destination mount point
+ * @recurse: whether this is a recursive bind mount
+ *
+ * Check permission before a bind mount is performed. Called with the
+ * source path already resolved, eliminating TOCTOU issues with
+ * string-based dev_name in security_sb_mount().
+ *
+ * Return: Returns 0 if permission is granted.
+ */
+int security_mount_bind(const struct path *from, const struct path *to,
+ bool recurse)
+{
+ return call_int_hook(mount_bind, from, to, recurse);
+}
+
+/**
+ * security_mount_new() - Check permissions for a new mount
+ * @fc: filesystem context with parsed options
+ * @mp: mount point path
+ * @mnt_flags: mount flags (MNT_*)
+ * @flags: original mount flags (MS_*, used by AppArmor/Tomoyo)
+ * @data: filesystem specific data (used by AppArmor)
+ *
+ * Check permission before a new filesystem is mounted. Called after
+ * mount options are parsed, providing access to the fs_context.
+ *
+ * Return: Returns 0 if permission is granted.
+ */
+int security_mount_new(struct fs_context *fc, const struct path *mp,
+ int mnt_flags, unsigned long flags, void *data)
+{
+ return call_int_hook(mount_new, fc, mp, mnt_flags, flags, data);
+}
+
+/**
+ * security_mount_remount() - Check permissions for a remount
+ * @fc: filesystem context with parsed options
+ * @mp: mount point path
+ * @mnt_flags: mount flags (MNT_*)
+ * @flags: original mount flags (MS_*, used by AppArmor/Tomoyo)
+ * @data: filesystem specific data (used by AppArmor)
+ *
+ * Check permission before a filesystem is remounted. Called after
+ * mount options are parsed, providing access to the fs_context.
+ *
+ * Return: Returns 0 if permission is granted.
+ */
+int security_mount_remount(struct fs_context *fc, const struct path *mp,
+ int mnt_flags, unsigned long flags, void *data)
+{
+ return call_int_hook(mount_remount, fc, mp, mnt_flags, flags, data);
+}
+
+/**
+ * security_mount_reconfigure() - Check permissions for mount reconfiguration
+ * @mp: mount point path
+ * @mnt_flags: new mount flags (MNT_*)
+ * @flags: original mount flags (MS_*, used by AppArmor/Tomoyo)
+ *
+ * Check permission before mount flags are reconfigured (MS_REMOUNT|MS_BIND).
+ *
+ * Return: Returns 0 if permission is granted.
+ */
+int security_mount_reconfigure(const struct path *mp, unsigned int mnt_flags,
+ unsigned long flags)
+{
+ return call_int_hook(mount_reconfigure, mp, mnt_flags, flags);
+}
+
+/**
+ * security_mount_move() - Check permissions for moving a mount
+ * @from_path: source mount path
+ * @to_path: destination mount point path
+ *
+ * Check permission before a mount is moved.
+ *
+ * Return: Returns 0 if permission is granted.
+ */
+int security_mount_move(const struct path *from_path,
+ const struct path *to_path)
+{
+ return call_int_hook(mount_move, from_path, to_path);
+}
+
+/**
+ * security_mount_change_type() - Check permissions for propagation changes
+ * @mp: mount point path
+ * @ms_flags: propagation flags (MS_SHARED, MS_PRIVATE, etc.)
+ *
+ * Check permission before mount propagation type is changed.
+ *
+ * Return: Returns 0 if permission is granted.
+ */
+int security_mount_change_type(const struct path *mp, int ms_flags)
+{
+ return call_int_hook(mount_change_type, mp, ms_flags);
+}
+
/**
* security_path_notify() - Check if setting a watch is allowed
* @path: file path
--
2.52.0
^ permalink raw reply related
* [PATCH v2 2/7] apparmor: Remove redundant MS_MGC_MSK stripping in apparmor_sb_mount
From: Song Liu @ 2026-04-30 0:03 UTC (permalink / raw)
To: linux-security-module, linux-fsdevel, selinux, apparmor
Cc: paul, jmorris, serge, viro, brauner, jack, john.johansen,
stephen.smalley.work, omosnace, mic, gnoack, takedakn,
penguin-kernel, herton, kernel-team, Song Liu
In-Reply-To: <20260430000315.918964-1-song@kernel.org>
path_mount() already strips the magic number from flags before
calling security_sb_mount(), so this check in apparmor_sb_mount()
is a no-op. Remove it.
Code generated with the assistance of Claude, reviewed by human.
Signed-off-by: Song Liu <song@kernel.org>
---
security/apparmor/lsm.c | 4 ----
1 file changed, 4 deletions(-)
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 3491e9f60194..4415bca5889c 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -705,10 +705,6 @@ static int apparmor_sb_mount(const char *dev_name, const struct path *path,
int error = 0;
bool needput;
- /* Discard magic */
- if ((flags & MS_MGC_MSK) == MS_MGC_VAL)
- flags &= ~MS_MGC_MSK;
-
flags &= ~AA_MS_IGNORE_MASK;
label = __begin_current_label_crit_section(&needput);
--
2.52.0
^ permalink raw reply related
* [PATCH v2 3/7] apparmor: Convert from sb_mount to granular mount hooks
From: Song Liu @ 2026-04-30 0:03 UTC (permalink / raw)
To: linux-security-module, linux-fsdevel, selinux, apparmor
Cc: paul, jmorris, serge, viro, brauner, jack, john.johansen,
stephen.smalley.work, omosnace, mic, gnoack, takedakn,
penguin-kernel, herton, kernel-team, Song Liu
In-Reply-To: <20260430000315.918964-1-song@kernel.org>
Replace AppArmor's monolithic apparmor_sb_mount() with granular
mount hooks.
Key changes:
- mount_bind: uses the pre-resolved struct path from VFS instead of
re-resolving dev_name via kern_path(), eliminating a TOCTOU
vulnerability. aa_bind_mount() now takes a struct path instead of
a string for the source.
- mount_new, mount_remount: receive the original mount(2) flags and
data parameters for policy matching via match_mnt_flags() and
AA_MNT_CONT_MATCH data matching.
- mount_reconfigure: handles MS_REMOUNT|MS_BIND (mount attribute
reconfiguration) which was previously handled as a remount.
- mount_move: reuses apparmor_move_mount() which already handles
pre-resolved paths.
- mount_change_type: propagation type changes.
aa_move_mount_old() is removed since move mounts now go through
security_mount_move() with pre-resolved struct path pointers for
both the old mount(2) and new move_mount(2) APIs.
Code generated with the assistance of Claude, reviewed by human.
Signed-off-by: Song Liu <song@kernel.org>
---
security/apparmor/include/mount.h | 5 +-
security/apparmor/lsm.c | 99 ++++++++++++++++++++++++-------
security/apparmor/mount.c | 37 ++----------
3 files changed, 83 insertions(+), 58 deletions(-)
diff --git a/security/apparmor/include/mount.h b/security/apparmor/include/mount.h
index 46834f828179..088e2f938cc1 100644
--- a/security/apparmor/include/mount.h
+++ b/security/apparmor/include/mount.h
@@ -31,16 +31,13 @@ int aa_remount(const struct cred *subj_cred,
int aa_bind_mount(const struct cred *subj_cred,
struct aa_label *label, const struct path *path,
- const char *old_name, unsigned long flags);
+ const struct path *old_path, bool recurse);
int aa_mount_change_type(const struct cred *subj_cred,
struct aa_label *label, const struct path *path,
unsigned long flags);
-int aa_move_mount_old(const struct cred *subj_cred,
- struct aa_label *label, const struct path *path,
- const char *old_name);
int aa_move_mount(const struct cred *subj_cred,
struct aa_label *label, const struct path *from_path,
const struct path *to_path);
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 4415bca5889c..e0a8a44c95aa 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -13,6 +13,7 @@
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/mount.h>
+#include <linux/fs_context.h>
#include <linux/namei.h>
#include <linux/ptrace.h>
#include <linux/ctype.h>
@@ -698,34 +699,83 @@ static int apparmor_uring_sqpoll(void)
}
#endif /* CONFIG_IO_URING */
-static int apparmor_sb_mount(const char *dev_name, const struct path *path,
- const char *type, unsigned long flags, void *data)
+static int apparmor_mount_bind(const struct path *from, const struct path *to,
+ bool recurse)
{
struct aa_label *label;
int error = 0;
bool needput;
- flags &= ~AA_MS_IGNORE_MASK;
+ label = __begin_current_label_crit_section(&needput);
+ if (!unconfined(label))
+ error = aa_bind_mount(current_cred(), label, to, from,
+ recurse);
+ __end_current_label_crit_section(label, needput);
+ return error;
+}
+
+static int apparmor_mount_new(struct fs_context *fc, const struct path *mp,
+ int mnt_flags, unsigned long flags, void *data)
+{
+ struct aa_label *label;
+ int error = 0;
+ bool needput;
+
+ /* flags and data are from the original mount(2) call */
label = __begin_current_label_crit_section(&needput);
- if (!unconfined(label)) {
- if (flags & MS_REMOUNT)
- error = aa_remount(current_cred(), label, path, flags,
- data);
- else if (flags & MS_BIND)
- error = aa_bind_mount(current_cred(), label, path,
- dev_name, flags);
- else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE |
- MS_UNBINDABLE))
- error = aa_mount_change_type(current_cred(), label,
- path, flags);
- else if (flags & MS_MOVE)
- error = aa_move_mount_old(current_cred(), label, path,
- dev_name);
- else
- error = aa_new_mount(current_cred(), label, dev_name,
- path, type, flags, data);
- }
+ if (!unconfined(label))
+ error = aa_new_mount(current_cred(), label, fc->source,
+ mp, fc->fs_type->name, flags, data);
+ __end_current_label_crit_section(label, needput);
+
+ return error;
+}
+
+static int apparmor_mount_remount(struct fs_context *fc, const struct path *mp,
+ int mnt_flags, unsigned long flags,
+ void *data)
+{
+ struct aa_label *label;
+ int error = 0;
+ bool needput;
+
+ /* flags and data are from the original mount(2) call */
+ label = __begin_current_label_crit_section(&needput);
+ if (!unconfined(label))
+ error = aa_remount(current_cred(), label, mp, flags, data);
+ __end_current_label_crit_section(label, needput);
+
+ return error;
+}
+
+static int apparmor_mount_reconfigure(const struct path *mp,
+ unsigned int mnt_flags,
+ unsigned long flags)
+{
+ struct aa_label *label;
+ int error = 0;
+ bool needput;
+
+ /* flags are from the original mount(2) call */
+ label = __begin_current_label_crit_section(&needput);
+ if (!unconfined(label))
+ error = aa_remount(current_cred(), label, mp, flags, NULL);
+ __end_current_label_crit_section(label, needput);
+
+ return error;
+}
+
+static int apparmor_mount_change_type(const struct path *mp, int ms_flags)
+{
+ struct aa_label *label;
+ int error = 0;
+ bool needput;
+
+ label = __begin_current_label_crit_section(&needput);
+ if (!unconfined(label))
+ error = aa_mount_change_type(current_cred(), label, mp,
+ ms_flags);
__end_current_label_crit_section(label, needput);
return error;
@@ -1656,7 +1706,12 @@ static struct security_hook_list apparmor_hooks[] __ro_after_init = {
LSM_HOOK_INIT(capable, apparmor_capable),
LSM_HOOK_INIT(move_mount, apparmor_move_mount),
- LSM_HOOK_INIT(sb_mount, apparmor_sb_mount),
+ LSM_HOOK_INIT(mount_bind, apparmor_mount_bind),
+ LSM_HOOK_INIT(mount_new, apparmor_mount_new),
+ LSM_HOOK_INIT(mount_remount, apparmor_mount_remount),
+ LSM_HOOK_INIT(mount_reconfigure, apparmor_mount_reconfigure),
+ LSM_HOOK_INIT(mount_move, apparmor_move_mount),
+ LSM_HOOK_INIT(mount_change_type, apparmor_mount_change_type),
LSM_HOOK_INIT(sb_umount, apparmor_sb_umount),
LSM_HOOK_INIT(sb_pivotroot, apparmor_sb_pivotroot),
diff --git a/security/apparmor/mount.c b/security/apparmor/mount.c
index 523570aa1a5a..38b40e16014f 100644
--- a/security/apparmor/mount.c
+++ b/security/apparmor/mount.c
@@ -418,25 +418,17 @@ int aa_remount(const struct cred *subj_cred,
}
int aa_bind_mount(const struct cred *subj_cred,
- struct aa_label *label, const struct path *path,
- const char *dev_name, unsigned long flags)
+ struct aa_label *label, const struct path *path,
+ const struct path *old_path, bool recurse)
{
struct aa_profile *profile;
char *buffer = NULL, *old_buffer = NULL;
- struct path old_path;
+ unsigned long flags = MS_BIND | (recurse ? MS_REC : 0);
int error;
AA_BUG(!label);
AA_BUG(!path);
-
- if (!dev_name || !*dev_name)
- return -EINVAL;
-
- flags &= MS_REC | MS_BIND;
-
- error = kern_path(dev_name, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &old_path);
- if (error)
- return error;
+ AA_BUG(!old_path);
buffer = aa_get_buffer(false);
old_buffer = aa_get_buffer(false);
@@ -445,12 +437,11 @@ int aa_bind_mount(const struct cred *subj_cred,
goto out;
error = fn_for_each_confined(label, profile,
- match_mnt(subj_cred, profile, path, buffer, &old_path,
+ match_mnt(subj_cred, profile, path, buffer, old_path,
old_buffer, NULL, flags, NULL, false));
out:
aa_put_buffer(buffer);
aa_put_buffer(old_buffer);
- path_put(&old_path);
return error;
}
@@ -514,24 +505,6 @@ int aa_move_mount(const struct cred *subj_cred,
return error;
}
-int aa_move_mount_old(const struct cred *subj_cred, struct aa_label *label,
- const struct path *path, const char *orig_name)
-{
- struct path old_path;
- int error;
-
- if (!orig_name || !*orig_name)
- return -EINVAL;
- error = kern_path(orig_name, LOOKUP_FOLLOW, &old_path);
- if (error)
- return error;
-
- error = aa_move_mount(subj_cred, label, &old_path, path);
- path_put(&old_path);
-
- return error;
-}
-
int aa_new_mount(const struct cred *subj_cred, struct aa_label *label,
const char *dev_name, const struct path *path,
const char *type, unsigned long flags, void *data)
--
2.52.0
^ permalink raw reply related
* [PATCH v2 4/7] selinux: Convert from sb_mount to granular mount hooks
From: Song Liu @ 2026-04-30 0:03 UTC (permalink / raw)
To: linux-security-module, linux-fsdevel, selinux, apparmor
Cc: paul, jmorris, serge, viro, brauner, jack, john.johansen,
stephen.smalley.work, omosnace, mic, gnoack, takedakn,
penguin-kernel, herton, kernel-team, Song Liu
In-Reply-To: <20260430000315.918964-1-song@kernel.org>
Replace selinux_mount() with granular mount hooks, preserving the
same permission checks:
- mount_bind, mount_new, mount_change_type: FILE__MOUNTON
- mount_remount, mount_reconfigure: FILESYSTEM__REMOUNT
- mount_move: FILE__MOUNTON (reuses selinux_move_mount)
The flags and data parameters are unused by SELinux.
Code generated with the assistance of Claude, reviewed by human.
Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Tested-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Song Liu <song@kernel.org>
---
security/selinux/hooks.c | 47 ++++++++++++++++++++++++++++++----------
1 file changed, 35 insertions(+), 12 deletions(-)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 97801966bf32..f0d9712356cf 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2802,19 +2802,37 @@ static int selinux_sb_statfs(struct dentry *dentry)
return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
}
-static int selinux_mount(const char *dev_name,
- const struct path *path,
- const char *type,
- unsigned long flags,
- void *data)
+static int selinux_mount_bind(const struct path *from, const struct path *to,
+ bool recurse)
{
- const struct cred *cred = current_cred();
+ return path_has_perm(current_cred(), to, FILE__MOUNTON);
+}
- if (flags & MS_REMOUNT)
- return superblock_has_perm(cred, path->dentry->d_sb,
- FILESYSTEM__REMOUNT, NULL);
- else
- return path_has_perm(cred, path, FILE__MOUNTON);
+static int selinux_mount_new(struct fs_context *fc, const struct path *mp,
+ int mnt_flags, unsigned long flags, void *data)
+{
+ return path_has_perm(current_cred(), mp, FILE__MOUNTON);
+}
+
+static int selinux_mount_remount(struct fs_context *fc, const struct path *mp,
+ int mnt_flags, unsigned long flags,
+ void *data)
+{
+ return superblock_has_perm(current_cred(), fc->root->d_sb,
+ FILESYSTEM__REMOUNT, NULL);
+}
+
+static int selinux_mount_reconfigure(const struct path *mp,
+ unsigned int mnt_flags,
+ unsigned long flags)
+{
+ return superblock_has_perm(current_cred(), mp->dentry->d_sb,
+ FILESYSTEM__REMOUNT, NULL);
+}
+
+static int selinux_mount_change_type(const struct path *mp, int ms_flags)
+{
+ return path_has_perm(current_cred(), mp, FILE__MOUNTON);
}
static int selinux_move_mount(const struct path *from_path,
@@ -7562,7 +7580,12 @@ static struct security_hook_list selinux_hooks[] __ro_after_init = {
LSM_HOOK_INIT(sb_kern_mount, selinux_sb_kern_mount),
LSM_HOOK_INIT(sb_show_options, selinux_sb_show_options),
LSM_HOOK_INIT(sb_statfs, selinux_sb_statfs),
- LSM_HOOK_INIT(sb_mount, selinux_mount),
+ LSM_HOOK_INIT(mount_bind, selinux_mount_bind),
+ LSM_HOOK_INIT(mount_new, selinux_mount_new),
+ LSM_HOOK_INIT(mount_remount, selinux_mount_remount),
+ LSM_HOOK_INIT(mount_reconfigure, selinux_mount_reconfigure),
+ LSM_HOOK_INIT(mount_change_type, selinux_mount_change_type),
+ LSM_HOOK_INIT(mount_move, selinux_move_mount),
LSM_HOOK_INIT(sb_umount, selinux_umount),
LSM_HOOK_INIT(sb_set_mnt_opts, selinux_set_mnt_opts),
LSM_HOOK_INIT(sb_clone_mnt_opts, selinux_sb_clone_mnt_opts),
--
2.52.0
^ permalink raw reply related
* [PATCH v2 5/7] landlock: Convert from sb_mount to granular mount hooks
From: Song Liu @ 2026-04-30 0:03 UTC (permalink / raw)
To: linux-security-module, linux-fsdevel, selinux, apparmor
Cc: paul, jmorris, serge, viro, brauner, jack, john.johansen,
stephen.smalley.work, omosnace, mic, gnoack, takedakn,
penguin-kernel, herton, kernel-team, Song Liu
In-Reply-To: <20260430000315.918964-1-song@kernel.org>
Replace hook_sb_mount() with granular mount hooks. Landlock denies
all mount operations for sandboxed processes regardless of flags,
so all new hooks share a common hook_mount_deny() helper. The
mount_move hook reuses hook_move_mount().
Code generated with the assistance of Claude, reviewed by human.
Signed-off-by: Song Liu <song@kernel.org>
---
security/landlock/fs.c | 40 ++++++++++++++++++++++++++++++++++++----
1 file changed, 36 insertions(+), 4 deletions(-)
diff --git a/security/landlock/fs.c b/security/landlock/fs.c
index c1ecfe239032..4547e736e496 100644
--- a/security/landlock/fs.c
+++ b/security/landlock/fs.c
@@ -1416,9 +1416,7 @@ static void log_fs_change_topology_dentry(
* inherit these new constraints. Anyway, for backward compatibility reasons,
* a dedicated user space option would be required (e.g. as a ruleset flag).
*/
-static int hook_sb_mount(const char *const dev_name,
- const struct path *const path, const char *const type,
- const unsigned long flags, void *const data)
+static int hook_mount_deny(const struct path *const path)
{
size_t handle_layer;
const struct landlock_cred_security *const subject =
@@ -1432,6 +1430,35 @@ static int hook_sb_mount(const char *const dev_name,
return -EPERM;
}
+static int hook_mount_bind(const struct path *const from,
+ const struct path *const to, bool recurse)
+{
+ return hook_mount_deny(to);
+}
+
+static int hook_mount_new(struct fs_context *fc, const struct path *const mp,
+ int mnt_flags, unsigned long flags, void *data)
+{
+ return hook_mount_deny(mp);
+}
+
+static int hook_mount_remount(struct fs_context *fc, const struct path *mp,
+ int mnt_flags, unsigned long flags, void *data)
+{
+ return hook_mount_deny(mp);
+}
+
+static int hook_mount_reconfigure(const struct path *const mp,
+ unsigned int mnt_flags, unsigned long flags)
+{
+ return hook_mount_deny(mp);
+}
+
+static int hook_mount_change_type(const struct path *const mp, int ms_flags)
+{
+ return hook_mount_deny(mp);
+}
+
static int hook_move_mount(const struct path *const from_path,
const struct path *const to_path)
{
@@ -1950,7 +1977,12 @@ static struct security_hook_list landlock_hooks[] __ro_after_init = {
LSM_HOOK_INIT(inode_free_security_rcu, hook_inode_free_security_rcu),
LSM_HOOK_INIT(sb_delete, hook_sb_delete),
- LSM_HOOK_INIT(sb_mount, hook_sb_mount),
+ LSM_HOOK_INIT(mount_bind, hook_mount_bind),
+ LSM_HOOK_INIT(mount_new, hook_mount_new),
+ LSM_HOOK_INIT(mount_remount, hook_mount_remount),
+ LSM_HOOK_INIT(mount_reconfigure, hook_mount_reconfigure),
+ LSM_HOOK_INIT(mount_change_type, hook_mount_change_type),
+ LSM_HOOK_INIT(mount_move, hook_move_mount),
LSM_HOOK_INIT(move_mount, hook_move_mount),
LSM_HOOK_INIT(sb_umount, hook_sb_umount),
LSM_HOOK_INIT(sb_remount, hook_sb_remount),
--
2.52.0
^ permalink raw reply related
* [PATCH v2 6/7] tomoyo: Convert from sb_mount to granular mount hooks
From: Song Liu @ 2026-04-30 0:03 UTC (permalink / raw)
To: linux-security-module, linux-fsdevel, selinux, apparmor
Cc: paul, jmorris, serge, viro, brauner, jack, john.johansen,
stephen.smalley.work, omosnace, mic, gnoack, takedakn,
penguin-kernel, herton, kernel-team, Song Liu
In-Reply-To: <20260430000315.918964-1-song@kernel.org>
Replace tomoyo_sb_mount() with granular mount hooks. Each hook
reconstructs the MS_* flags expected by tomoyo_mount_permission()
using the original flags parameter where available.
Key changes:
- mount_bind: passes the pre-resolved source path to
tomoyo_mount_acl() via a new dev_path parameter, instead of
re-resolving dev_name via kern_path(). This eliminates a TOCTOU
vulnerability.
- mount_new, mount_remount, mount_reconfigure: use the original
mount(2) flags for policy matching.
- mount_move: passes pre-resolved paths for both source and
destination.
- mount_change_type: passes raw ms_flags directly.
Also removes the unused data_page parameter from
tomoyo_mount_permission().
Code generated with the assistance of Claude, reviewed by human.
Signed-off-by: Song Liu <song@kernel.org>
---
security/tomoyo/common.h | 2 +-
security/tomoyo/mount.c | 31 +++++++++++++-------
security/tomoyo/tomoyo.c | 63 ++++++++++++++++++++++++++++++----------
3 files changed, 70 insertions(+), 26 deletions(-)
diff --git a/security/tomoyo/common.h b/security/tomoyo/common.h
index d098cf8aae61..9241034cfede 100644
--- a/security/tomoyo/common.h
+++ b/security/tomoyo/common.h
@@ -1013,7 +1013,7 @@ int tomoyo_mkdev_perm(const u8 operation, const struct path *path,
const unsigned int mode, unsigned int dev);
int tomoyo_mount_permission(const char *dev_name, const struct path *path,
const char *type, unsigned long flags,
- void *data_page);
+ const struct path *dev_path);
int tomoyo_open_control(const u8 type, struct file *file);
int tomoyo_path2_perm(const u8 operation, const struct path *path1,
const struct path *path2);
diff --git a/security/tomoyo/mount.c b/security/tomoyo/mount.c
index 322dfd188ada..82ffe7d02814 100644
--- a/security/tomoyo/mount.c
+++ b/security/tomoyo/mount.c
@@ -70,6 +70,7 @@ static bool tomoyo_check_mount_acl(struct tomoyo_request_info *r,
* @dir: Pointer to "struct path".
* @type: Name of filesystem type.
* @flags: Mount options.
+ * @dev_path: Pre-resolved device/source path. Maybe NULL.
*
* Returns 0 on success, negative value otherwise.
*
@@ -78,11 +79,11 @@ static bool tomoyo_check_mount_acl(struct tomoyo_request_info *r,
static int tomoyo_mount_acl(struct tomoyo_request_info *r,
const char *dev_name,
const struct path *dir, const char *type,
- unsigned long flags)
+ unsigned long flags,
+ const struct path *dev_path)
__must_hold_shared(&tomoyo_ss)
{
struct tomoyo_obj_info obj = { };
- struct path path;
struct file_system_type *fstype = NULL;
const char *requested_type = NULL;
const char *requested_dir_name = NULL;
@@ -134,13 +135,23 @@ static int tomoyo_mount_acl(struct tomoyo_request_info *r,
need_dev = 1;
}
if (need_dev) {
- /* Get mount point or device file. */
- if (!dev_name || kern_path(dev_name, LOOKUP_FOLLOW, &path)) {
+ if (dev_path) {
+ /* Use pre-resolved path to avoid TOCTOU issues. */
+ obj.path1 = *dev_path;
+ path_get(&obj.path1);
+ } else if (!dev_name) {
error = -ENOENT;
goto out;
+ } else {
+ struct path path;
+
+ if (kern_path(dev_name, LOOKUP_FOLLOW, &path)) {
+ error = -ENOENT;
+ goto out;
+ }
+ obj.path1 = path;
}
- obj.path1 = path;
- requested_dev_name = tomoyo_realpath_from_path(&path);
+ requested_dev_name = tomoyo_realpath_from_path(&obj.path1);
if (!requested_dev_name) {
error = -ENOENT;
goto out;
@@ -173,7 +184,7 @@ static int tomoyo_mount_acl(struct tomoyo_request_info *r,
if (fstype)
put_filesystem(fstype);
kfree(requested_type);
- /* Drop refcount obtained by kern_path(). */
+ /* Drop refcount obtained by kern_path() or path_get(). */
if (obj.path1.dentry)
path_put(&obj.path1);
return error;
@@ -186,13 +197,13 @@ static int tomoyo_mount_acl(struct tomoyo_request_info *r,
* @path: Pointer to "struct path".
* @type: Name of filesystem type. Maybe NULL.
* @flags: Mount options.
- * @data_page: Optional data. Maybe NULL.
+ * @dev_path: Pre-resolved device/source path. Maybe NULL.
*
* Returns 0 on success, negative value otherwise.
*/
int tomoyo_mount_permission(const char *dev_name, const struct path *path,
const char *type, unsigned long flags,
- void *data_page)
+ const struct path *dev_path)
{
struct tomoyo_request_info r;
int error;
@@ -236,7 +247,7 @@ int tomoyo_mount_permission(const char *dev_name, const struct path *path,
if (!type)
type = "<NULL>";
idx = tomoyo_read_lock();
- error = tomoyo_mount_acl(&r, dev_name, path, type, flags);
+ error = tomoyo_mount_acl(&r, dev_name, path, type, flags, dev_path);
tomoyo_read_unlock(idx);
return error;
}
diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c
index c66e02ed8ee3..ac84e1f03d5e 100644
--- a/security/tomoyo/tomoyo.c
+++ b/security/tomoyo/tomoyo.c
@@ -6,6 +6,8 @@
*/
#include <linux/lsm_hooks.h>
+#include <linux/fs_context.h>
+#include <uapi/linux/mount.h>
#include <uapi/linux/lsm.h>
#include "common.h"
@@ -398,21 +400,47 @@ static int tomoyo_path_chroot(const struct path *path)
return tomoyo_path_perm(TOMOYO_TYPE_CHROOT, path, NULL);
}
-/**
- * tomoyo_sb_mount - Target for security_sb_mount().
- *
- * @dev_name: Name of device file. Maybe NULL.
- * @path: Pointer to "struct path".
- * @type: Name of filesystem type. Maybe NULL.
- * @flags: Mount options.
- * @data: Optional data. Maybe NULL.
- *
- * Returns 0 on success, negative value otherwise.
- */
-static int tomoyo_sb_mount(const char *dev_name, const struct path *path,
- const char *type, unsigned long flags, void *data)
+static int tomoyo_mount_bind(const struct path *from, const struct path *to,
+ bool recurse)
+{
+ unsigned long flags = MS_BIND | (recurse ? MS_REC : 0);
+
+ return tomoyo_mount_permission(NULL, to, NULL, flags, from);
+}
+
+static int tomoyo_mount_new(struct fs_context *fc, const struct path *mp,
+ int mnt_flags, unsigned long flags, void *data)
+{
+ /* Use original MS_* flags for policy matching */
+ return tomoyo_mount_permission(fc->source, mp, fc->fs_type->name,
+ flags, NULL);
+}
+
+static int tomoyo_mount_remount(struct fs_context *fc, const struct path *mp,
+ int mnt_flags, unsigned long flags, void *data)
+{
+ /* Use original MS_* flags for policy matching */
+ return tomoyo_mount_permission(NULL, mp, NULL, flags, NULL);
+}
+
+static int tomoyo_mount_reconfigure(const struct path *mp,
+ unsigned int mnt_flags,
+ unsigned long flags)
+{
+ /* Use original MS_* flags for policy matching */
+ return tomoyo_mount_permission(NULL, mp, NULL, flags, NULL);
+}
+
+static int tomoyo_mount_change_type(const struct path *mp, int ms_flags)
+{
+ return tomoyo_mount_permission(NULL, mp, NULL, ms_flags, NULL);
+}
+
+static int tomoyo_move_mount(const struct path *from_path,
+ const struct path *to_path)
{
- return tomoyo_mount_permission(dev_name, path, type, flags, data);
+ return tomoyo_mount_permission(NULL, to_path, NULL, MS_MOVE,
+ from_path);
}
/**
@@ -576,7 +604,12 @@ static struct security_hook_list tomoyo_hooks[] __ro_after_init = {
LSM_HOOK_INIT(path_chmod, tomoyo_path_chmod),
LSM_HOOK_INIT(path_chown, tomoyo_path_chown),
LSM_HOOK_INIT(path_chroot, tomoyo_path_chroot),
- LSM_HOOK_INIT(sb_mount, tomoyo_sb_mount),
+ LSM_HOOK_INIT(mount_bind, tomoyo_mount_bind),
+ LSM_HOOK_INIT(mount_new, tomoyo_mount_new),
+ LSM_HOOK_INIT(mount_remount, tomoyo_mount_remount),
+ LSM_HOOK_INIT(mount_reconfigure, tomoyo_mount_reconfigure),
+ LSM_HOOK_INIT(mount_change_type, tomoyo_mount_change_type),
+ LSM_HOOK_INIT(mount_move, tomoyo_move_mount),
LSM_HOOK_INIT(sb_umount, tomoyo_sb_umount),
LSM_HOOK_INIT(sb_pivotroot, tomoyo_sb_pivotroot),
LSM_HOOK_INIT(socket_bind, tomoyo_socket_bind),
--
2.52.0
^ permalink raw reply related
* [PATCH v2 7/7] lsm: Remove security_sb_mount and security_move_mount
From: Song Liu @ 2026-04-30 0:03 UTC (permalink / raw)
To: linux-security-module, linux-fsdevel, selinux, apparmor
Cc: paul, jmorris, serge, viro, brauner, jack, john.johansen,
stephen.smalley.work, omosnace, mic, gnoack, takedakn,
penguin-kernel, herton, kernel-team, Song Liu
In-Reply-To: <20260430000315.918964-1-song@kernel.org>
Now that all LSMs have been converted to granular mount hooks,
remove the old hooks:
- security_sb_mount(): removed from lsm_hook_defs.h, security.h,
security.c, and its call in path_mount().
- security_move_mount(): removed and replaced by security_mount_move()
in do_move_mount(). All LSMs now use mount_move exclusively.
Code generated with the assistance of Claude, reviewed by human.
Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Tested-by: Stephen Smalley <stephen.smalley.work@gmail.com> # for selinux only
Signed-off-by: Song Liu <song@kernel.org>
---
fs/namespace.c | 6 +-----
include/linux/lsm_hook_defs.h | 4 ----
include/linux/security.h | 16 ---------------
kernel/bpf/bpf_lsm.c | 2 --
security/apparmor/lsm.c | 1 -
security/landlock/fs.c | 1 -
security/security.c | 38 -----------------------------------
security/selinux/hooks.c | 2 --
8 files changed, 1 insertion(+), 69 deletions(-)
diff --git a/fs/namespace.c b/fs/namespace.c
index e263319fb333..43f22c5e2bf4 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -4103,7 +4103,6 @@ int path_mount(const char *dev_name, const struct path *path,
const char *type_page, unsigned long flags, void *data_page)
{
unsigned int mnt_flags = 0, sb_flags;
- int ret;
/* Discard magic */
if ((flags & MS_MGC_MSK) == MS_MGC_VAL)
@@ -4116,9 +4115,6 @@ int path_mount(const char *dev_name, const struct path *path,
if (flags & MS_NOUSER)
return -EINVAL;
- ret = security_sb_mount(dev_name, path, type_page, flags, data_page);
- if (ret)
- return ret;
if (!may_mount())
return -EPERM;
if (flags & SB_MANDLOCK)
@@ -4568,7 +4564,7 @@ static inline int vfs_move_mount(const struct path *from_path,
{
int ret;
- ret = security_move_mount(from_path, to_path);
+ ret = security_mount_move(from_path, to_path);
if (ret)
return ret;
diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index 98f0fe382665..c870260bf402 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -69,8 +69,6 @@ LSM_HOOK(int, 0, sb_remount, struct super_block *sb, void *mnt_opts)
LSM_HOOK(int, 0, sb_kern_mount, const struct super_block *sb)
LSM_HOOK(int, 0, sb_show_options, struct seq_file *m, struct super_block *sb)
LSM_HOOK(int, 0, sb_statfs, struct dentry *dentry)
-LSM_HOOK(int, 0, sb_mount, const char *dev_name, const struct path *path,
- const char *type, unsigned long flags, void *data)
LSM_HOOK(int, 0, sb_umount, struct vfsmount *mnt, int flags)
LSM_HOOK(int, 0, sb_pivotroot, const struct path *old_path,
const struct path *new_path)
@@ -79,8 +77,6 @@ LSM_HOOK(int, 0, sb_set_mnt_opts, struct super_block *sb, void *mnt_opts,
LSM_HOOK(int, 0, sb_clone_mnt_opts, const struct super_block *oldsb,
struct super_block *newsb, unsigned long kern_flags,
unsigned long *set_kern_flags)
-LSM_HOOK(int, 0, move_mount, const struct path *from_path,
- const struct path *to_path)
LSM_HOOK(int, 0, mount_bind, const struct path *from, const struct path *to,
bool recurse)
LSM_HOOK(int, 0, mount_new, struct fs_context *fc, const struct path *mp,
diff --git a/include/linux/security.h b/include/linux/security.h
index b1b3da51a88d..f1dcfc569cf2 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -373,8 +373,6 @@ int security_sb_remount(struct super_block *sb, void *mnt_opts);
int security_sb_kern_mount(const struct super_block *sb);
int security_sb_show_options(struct seq_file *m, struct super_block *sb);
int security_sb_statfs(struct dentry *dentry);
-int security_sb_mount(const char *dev_name, const struct path *path,
- const char *type, unsigned long flags, void *data);
int security_sb_umount(struct vfsmount *mnt, int flags);
int security_sb_pivotroot(const struct path *old_path, const struct path *new_path);
int security_sb_set_mnt_opts(struct super_block *sb,
@@ -385,7 +383,6 @@ int security_sb_clone_mnt_opts(const struct super_block *oldsb,
struct super_block *newsb,
unsigned long kern_flags,
unsigned long *set_kern_flags);
-int security_move_mount(const struct path *from_path, const struct path *to_path);
int security_mount_bind(const struct path *from, const struct path *to,
bool recurse);
int security_mount_new(struct fs_context *fc, const struct path *mp,
@@ -825,13 +822,6 @@ static inline int security_sb_statfs(struct dentry *dentry)
return 0;
}
-static inline int security_sb_mount(const char *dev_name, const struct path *path,
- const char *type, unsigned long flags,
- void *data)
-{
- return 0;
-}
-
static inline int security_sb_umount(struct vfsmount *mnt, int flags)
{
return 0;
@@ -859,12 +849,6 @@ static inline int security_sb_clone_mnt_opts(const struct super_block *oldsb,
return 0;
}
-static inline int security_move_mount(const struct path *from_path,
- const struct path *to_path)
-{
- return 0;
-}
-
static inline int security_mount_bind(const struct path *from,
const struct path *to, bool recurse)
{
diff --git a/kernel/bpf/bpf_lsm.c b/kernel/bpf/bpf_lsm.c
index aa228372cfb4..77371ca25d09 100644
--- a/kernel/bpf/bpf_lsm.c
+++ b/kernel/bpf/bpf_lsm.c
@@ -350,7 +350,6 @@ BTF_ID(func, bpf_lsm_release_secctx)
BTF_ID(func, bpf_lsm_sb_alloc_security)
BTF_ID(func, bpf_lsm_sb_eat_lsm_opts)
BTF_ID(func, bpf_lsm_sb_kern_mount)
-BTF_ID(func, bpf_lsm_sb_mount)
BTF_ID(func, bpf_lsm_sb_remount)
BTF_ID(func, bpf_lsm_sb_set_mnt_opts)
BTF_ID(func, bpf_lsm_sb_show_options)
@@ -382,7 +381,6 @@ BTF_ID(func, bpf_lsm_task_setscheduler)
BTF_ID(func, bpf_lsm_userns_create)
BTF_ID(func, bpf_lsm_bdev_alloc_security)
BTF_ID(func, bpf_lsm_bdev_setintegrity)
-BTF_ID(func, bpf_lsm_move_mount)
BTF_ID(func, bpf_lsm_mount_bind)
BTF_ID(func, bpf_lsm_mount_new)
BTF_ID(func, bpf_lsm_mount_remount)
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index e0a8a44c95aa..b0de7f316f51 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -1705,7 +1705,6 @@ static struct security_hook_list apparmor_hooks[] __ro_after_init = {
LSM_HOOK_INIT(capget, apparmor_capget),
LSM_HOOK_INIT(capable, apparmor_capable),
- LSM_HOOK_INIT(move_mount, apparmor_move_mount),
LSM_HOOK_INIT(mount_bind, apparmor_mount_bind),
LSM_HOOK_INIT(mount_new, apparmor_mount_new),
LSM_HOOK_INIT(mount_remount, apparmor_mount_remount),
diff --git a/security/landlock/fs.c b/security/landlock/fs.c
index 4547e736e496..7377f22a165e 100644
--- a/security/landlock/fs.c
+++ b/security/landlock/fs.c
@@ -1983,7 +1983,6 @@ static struct security_hook_list landlock_hooks[] __ro_after_init = {
LSM_HOOK_INIT(mount_reconfigure, hook_mount_reconfigure),
LSM_HOOK_INIT(mount_change_type, hook_mount_change_type),
LSM_HOOK_INIT(mount_move, hook_move_mount),
- LSM_HOOK_INIT(move_mount, hook_move_mount),
LSM_HOOK_INIT(sb_umount, hook_sb_umount),
LSM_HOOK_INIT(sb_remount, hook_sb_remount),
LSM_HOOK_INIT(sb_pivotroot, hook_sb_pivotroot),
diff --git a/security/security.c b/security/security.c
index b7ec0ec7af26..bc55ee588c59 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1065,29 +1065,6 @@ int security_sb_statfs(struct dentry *dentry)
return call_int_hook(sb_statfs, dentry);
}
-/**
- * security_sb_mount() - Check permission for mounting a filesystem
- * @dev_name: filesystem backing device
- * @path: mount point
- * @type: filesystem type
- * @flags: mount flags
- * @data: filesystem specific data
- *
- * Check permission before an object specified by @dev_name is mounted on the
- * mount point named by @nd. For an ordinary mount, @dev_name identifies a
- * device if the file system type requires a device. For a remount
- * (@flags & MS_REMOUNT), @dev_name is irrelevant. For a loopback/bind mount
- * (@flags & MS_BIND), @dev_name identifies the pathname of the object being
- * mounted.
- *
- * Return: Returns 0 if permission is granted.
- */
-int security_sb_mount(const char *dev_name, const struct path *path,
- const char *type, unsigned long flags, void *data)
-{
- return call_int_hook(sb_mount, dev_name, path, type, flags, data);
-}
-
/**
* security_sb_umount() - Check permission for unmounting a filesystem
* @mnt: mounted filesystem
@@ -1167,21 +1144,6 @@ int security_sb_clone_mnt_opts(const struct super_block *oldsb,
}
EXPORT_SYMBOL(security_sb_clone_mnt_opts);
-/**
- * security_move_mount() - Check permissions for moving a mount
- * @from_path: source mount point
- * @to_path: destination mount point
- *
- * Check permission before a mount is moved.
- *
- * Return: Returns 0 if permission is granted.
- */
-int security_move_mount(const struct path *from_path,
- const struct path *to_path)
-{
- return call_int_hook(move_mount, from_path, to_path);
-}
-
/**
* security_mount_bind() - Check permissions for a bind mount
* @from: source path
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index f0d9712356cf..b6229fb619cf 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -7590,8 +7590,6 @@ static struct security_hook_list selinux_hooks[] __ro_after_init = {
LSM_HOOK_INIT(sb_set_mnt_opts, selinux_set_mnt_opts),
LSM_HOOK_INIT(sb_clone_mnt_opts, selinux_sb_clone_mnt_opts),
- LSM_HOOK_INIT(move_mount, selinux_move_mount),
-
LSM_HOOK_INIT(dentry_init_security, selinux_dentry_init_security),
LSM_HOOK_INIT(dentry_create_files_as, selinux_dentry_create_files_as),
--
2.52.0
^ permalink raw reply related
* Re: [RFC PATCH v2 1/4] security: ima: call ima_init() again at late_initcall_sync for defered TPM
From: Paul Moore @ 2026-04-30 0:36 UTC (permalink / raw)
To: Yeoreum Yun
Cc: Mimi Zohar, roberto.sassu, Jonathan McDowell,
linux-security-module, linux-kernel, linux-integrity,
linux-arm-kernel, kvmarm, jmorris, serge, dmitry.kasatkin,
eric.snowberg, jarkko, jgg, sudeep.holla, maz, oupton, joey.gouly,
suzuki.poulose, yuzenghui, catalin.marinas, will, noodles,
sebastianene
In-Reply-To: <afC0UPfGhNTsXnyi@e129823.arm.com>
On Tue, Apr 28, 2026 at 9:21 AM Yeoreum Yun <yeoreum.yun@arm.com> wrote:
> > On Fri, Apr 24, 2026 at 6:49 PM Mimi Zohar <zohar@linux.ibm.com> wrote:
> > > On Fri, 2026-04-24 at 18:10 -0400, Paul Moore wrote:
> > > > (I'm assuming you meant initcall and not syscall above, but if you're
> > > > talking about something else, please let me know.)
> > > >
> > > > Saying that you aren't comfortable moving IMA initialization to
> > > > late-sync is inconsistent with allowing IMA initialization to be
> > > > deferred to late-sync. Either it is okay to initialize IMA in
> > > > late-sync or it isn't. You must pick one.
> > >
> > > Yes, we're discussing late_initcall and late_initcall_sync.
> > >
> > > I prefer to look at it as being pragmatic. I'd rather err on the side of caution
> > > and not move the syscall to late_initcall_sync, than move it.
> >
> > If you were truly erring on the side of caution you wouldn't allow
> > late-sync initialization without knowing if it was safe or not.
> > Determine whether IMA initialization is safe at late-sync. If it is
> > safe, move the init to late-sync; if not, keep it at late and figure
> > out another mechanism to sync with the TPM availability. If needed,
> > you could probably use the LSM notifier to enable the TPM driver to
> > signal when it is up and running.
>
> I don't think LSM notifier wouldn't be good since it a one time
> notification for initailisation and it wouldn't tell properly
> whehter TPM isn't present in system or present unless functions
> ima_init() are rewritten to discern the "TPM deferred" and
> "TPM doesn't exist" in the system (e.x) boot-aggregate log creation.
Yes, some work would needed to differentiate between TPM present and
TPM absent, the notifier would simply be a mechanism for the TPM
driver layer to signal to IMA (and potentially other LSMs if needed?)
that the TPM device was initialized and ready.
> One question, though.
> In the end, for systems where the TPM has already been probed by late_initcall(),
> init_ima() continues to be called at late_initcall(), while the above approach
> is introduced for systems where the TPM is not properly initialized by that point.
>
> If init_ima(), which used to be called at late_initcall(),
> were instead called at late_initcall_sync(), could this break system integration?
> In my view, both late_initcall and late_initcall_sync run during the do_basic_setup() phase,
> so it doesn’t seem like this would cause tampering or affect things like the creation of the boot-aggregate log.
>
> Is there any particular reason why init_ima() must be called specifically at late_initcall()?
That is something that you, and the IMA devs need to answer.
--
paul-moore.com
^ permalink raw reply
* Re: [RFC PATCH v2 1/4] security: ima: call ima_init() again at late_initcall_sync for defered TPM
From: Paul Moore @ 2026-04-30 0:43 UTC (permalink / raw)
To: Roberto Sassu
Cc: Mimi Zohar, Yeoreum Yun, roberto.sassu, Jonathan McDowell,
linux-security-module, linux-kernel, linux-integrity,
linux-arm-kernel, kvmarm, jmorris, serge, dmitry.kasatkin,
eric.snowberg, jarkko, jgg, sudeep.holla, maz, oupton, joey.gouly,
suzuki.poulose, yuzenghui, catalin.marinas, will, noodles,
sebastianene
In-Reply-To: <e325b7a8041b7122e8415de9193f4fe1be04bb02.camel@huaweicloud.com>
On Wed, Apr 29, 2026 at 9:33 AM Roberto Sassu
<roberto.sassu@huaweicloud.com> wrote:
> On Mon, 2026-04-27 at 21:31 -0400, Paul Moore wrote:
> > On Fri, Apr 24, 2026 at 6:49 PM Mimi Zohar <zohar@linux.ibm.com> wrote:
> > > On Fri, 2026-04-24 at 18:10 -0400, Paul Moore wrote:
> > > > (I'm assuming you meant initcall and not syscall above, but if you're
> > > > talking about something else, please let me know.)
> > > >
> > > > Saying that you aren't comfortable moving IMA initialization to
> > > > late-sync is inconsistent with allowing IMA initialization to be
> > > > deferred to late-sync. Either it is okay to initialize IMA in
> > > > late-sync or it isn't. You must pick one.
> > >
> > > Yes, we're discussing late_initcall and late_initcall_sync.
> > >
> > > I prefer to look at it as being pragmatic. I'd rather err on the side of caution
> > > and not move the syscall to late_initcall_sync, than move it.
> >
> > If you were truly erring on the side of caution you wouldn't allow
> > late-sync initialization without knowing if it was safe or not.
> > Determine whether IMA initialization is safe at late-sync. If it is
> > safe, move the init to late-sync; if not, keep it at late and figure
> > out another mechanism to sync with the TPM availability. If needed,
> > you could probably use the LSM notifier to enable the TPM driver to
> > signal when it is up and running.
>
> Yes, I agree with you, or transition or not.
>
> However, all of this looks very fragile and easy to be broken. If we
> want to be on the safe side, we can use any notification mechanism that
> is suitable, but at the same time from IMA side we need to deny any
> file access that would require a measurement until the TPM comes up.
>
> If you accept this, I don't have any problem to move to late_sync.
To be perfectly honest, I don't care what the solution to the IMA/TPM
dependency issue looks like as long as it doesn't involve simply
trying to initialize IMA multiple times hoping that at one of those
times all of the dependencies have been satisfied and it isn't too
late.
If the notifier helps you solve this, great. If the notifier isn't
helpful, that's fine too.
If you need to decompose IMA initialization into a multi-step process
spread across multiple initcall levels, that's okay; we do that with
other LSMs. However, calling into the same init code across multiple
initcall levels is not okay; you need to figure out what is needed
when, and establish some synchronization mechanisms to provide some
assurance that the system will boot up correctly.
--
paul-moore.com
^ permalink raw reply
* [linus:master] [landlock] 874c8f8382: kernel-selftests.landlock.audit_test.audit.thread.fail
From: kernel test robot @ 2026-04-30 2:51 UTC (permalink / raw)
To: Mickaël Salaün
Cc: oe-lkp, lkp, linux-kernel, Günther Noack, Jann Horn,
Günther Noack, linux-security-module, oliver.sang
Hello,
kernel test robot noticed "kernel-selftests.landlock.audit_test.audit.thread.fail" on:
commit: 874c8f83826c95c62c21d9edfe9ef43e5c346724 ("landlock: Fix LOG_SUBDOMAINS_OFF inheritance across fork()")
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
[test failed on linus/master dca922e019dd758b4c1b4bec8f1d509efddeaab4]
[test failed on linux-next/master 9974969c14031a097d6b45bcb7a06bb4aa525c40]
in testcase: kernel-selftests
version: kernel-selftests-x86_64-9f2693489ef8-1_20260201
with following parameters:
group: landlock
config: x86_64-rhel-9.4-kselftests
compiler: gcc-14
test machine: 16 threads Intel(R) Core(TM) i7-13620H (Raptor Lake) with 32G memory
(please refer to attached dmesg/kmsg for entire log/backtrace)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <oliver.sang@intel.com>
| Closes: https://lore.kernel.org/oe-lkp/202604300436.a07fae12-lkp@intel.com
# timeout set to 300
# selftests: landlock: audit_test
# TAP version 13
# 1..12
# # Starting 12 tests from 10 test cases.
# # RUN audit.log_subdomains_off_fork ...
# # OK audit.log_subdomains_off_fork
# ok 1 audit.log_subdomains_off_fork
# # RUN audit.thread ...
# # audit_test.c:252:thread:Expected 0 (0) == matches_log_signal(_metadata, self->audit_fd, child_data.parent_pid, &denial_dom) (-11)
# # audit_test.c:254:thread:Expected denial_dom (1) != 1 (1)
# # audit_test.c:257:thread:Expected 0 (0) == matches_log_domain_allocated(self->audit_fd, getpid(), &allocated_dom) (-11)
# # audit_test.c:259:thread:Expected denial_dom (1) == allocated_dom (2)
# DATA: audit(1777390809.810:10): domain=1a323af0a status=allocated mode=enforcing pid=2437 uid=0 exe="/opt/rootfs/tmp/kselftests/landlock/landlock/audit_test" comm="audit_test"
# ERROR: no match for pattern: ^audit([0-9.:]\+): domain=\([0-9a-f]\+\) status=deallocated denials=1$
# # audit_test.c:275:thread:Expected 0 (0) == matches_log_domain_deallocated(self->audit_fd, 1, &deallocated_dom) (-2)
# # audit_test.c:277:thread:Expected denial_dom (1) == deallocated_dom (0)
# # thread: Test failed
# # FAIL audit.thread
# not ok 2 audit.thread
The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20260430/202604300436.a07fae12-lkp@intel.com
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply
* Re: [PATCH] ima: debugging late_initcall_sync measurements
From: Yeoreum Yun @ 2026-04-30 9:48 UTC (permalink / raw)
To: Mimi Zohar
Cc: Jonathan McDowell, linux-security-module, linux-kernel,
linux-integrity, linux-arm-kernel, kvmarm, paul, jmorris, serge,
roberto.sassu, dmitry.kasatkin, eric.snowberg, jarkko, jgg,
sudeep.holla, maz, oupton, joey.gouly, suzuki.poulose, yuzenghui,
catalin.marinas, will, noodles, sebastianene
In-Reply-To: <7734099f5e7fda5480bca016a9e6707983325fbd.camel@linux.ibm.com>
Hi Mimi,
Thanks to share the testing code and please see the below:
> With this "[RFC PATCH v3 0/4] Fix IMA + TPM initialisation ordering
> issue" patch set, how many records would be missing if IMA
> initialization is deferred to late_initcall_sync [1]?
>
> [1]https://lore.kernel.org/linux-integrity/cover.1777036497.git.noodles@meta.com/
> ---
> Jonathan, Yeoreum, others -
>
> By going into TPM-bypass mode, we can see how many measurements are actually
> missing when deferring IMA initialization to late_initcall_sync. As this is
> system/TPM dependent, I'd appreciate your checking. Please use the boot command
> line option "ima_policy=tcb|critical_data".
>
> thanks, Mimi
>
> security/integrity/ima/ima.h | 1 +
> security/integrity/ima/ima_init.c | 6 ++++++
> security/integrity/ima/ima_main.c | 19 +++++++++++++++++++
> 3 files changed, 26 insertions(+)
>
> diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
> index 01aae19ed365..9a1117112fb2 100644
> --- a/security/integrity/ima/ima.h
> +++ b/security/integrity/ima/ima.h
> @@ -286,6 +286,7 @@ extern bool ima_canonical_fmt;
>
> /* Internal IMA function definitions */
> int ima_init_core(bool late);
> +int ima_init_debug(bool late);
> int ima_fs_init(void);
> int ima_add_template_entry(struct ima_template_entry *entry, int violation,
> const char *op, struct inode *inode,
> diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
> index 5f335834a9bb..edd063b99685 100644
> --- a/security/integrity/ima/ima_init.c
> +++ b/security/integrity/ima/ima_init.c
> @@ -122,6 +122,12 @@ void __init ima_load_x509(void)
> }
> #endif
>
> +int __init ima_init_debug(bool late)
> +{
> + ima_add_boot_aggregate(late); /* just add an additional record */
> + return 0;
> +}
> +
> int __init ima_init_core(bool late)
> {
> int rc;
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index 42099bfe7e43..23e669be54fc 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -1254,6 +1254,7 @@ static int ima_kernel_module_request(char *kmod_name)
>
> #endif /* CONFIG_INTEGRITY_ASYMMETRIC_KEYS */
>
> +#define TESTING 1
> static int __init init_ima(bool late)
> {
> int error;
> @@ -1264,6 +1265,23 @@ static int __init init_ima(bool late)
> return 0;
> }
>
> +#ifdef TESTING
> + /*
> + * Initialize early, even if it means going into TPM-bypass mode,
> + * but add an additional boot_aggregrate message for the
> + * late_initcall_sync.
> + *
> + * If measurement list records exist between the boot_aggregate
> + * and the boot_aggregate_late records, these records would be
> + * missing when IMA initializion is deferred to late_initcall_sync.
> + */
> + if (ima_tpm_chip) {
I believe this should be:
if (late) {
...
}
> + ima_init_debug(late); /* Add an additional record */
> + return 0;
> + }
> +
> + ima_tpm_chip = tpm_default_chip();
> +#elif
> /*
> * If we found the TPM during our first attempt, or we know there's no
> * TPM, nothing further to do
> @@ -1276,6 +1294,7 @@ static int __init init_ima(bool late)
> pr_debug("TPM not available, will try later\n");
> return -EPROBE_DEFER;
> }
> +#endif
>
> if (!ima_tpm_chip)
> pr_info("No TPM chip found, activating TPM-bypass!\n");
> --
> 2.53.0
With above change I confirmed there is no meaurement log
between boot_aggregate and boot_aggregate_late except "kernel_version"
But this is ignorable since this UTS measurement is done in
"ima_init_core() (old: ima_init())" and it is part of ima initialisation.
1. ima_policy=tcb
# cat /sys/kernel/security/ima/ascii_runtime_measurements
10 0adefe762c149c7cec19da62f0da1297fcfbffff ima-ng sha256:0000000000000000000000000000000000000000000000000000000000000000 boot_aggregate
10 4e5d73ebadfd8f850cb93ce4de755ba148a9a7d5 ima-ng sha256:0000000000000000000000000000000000000000000000000000000000000000 boot_aggregate_late
10 7c23cc970eceec906f7a41bc2fbde770d7092209 ima-ng sha256:72ade6ae3d35cfe5ede7a77b1c0ed1d1782a899445fdcb219c0e994a084a70d5 /bin/busybox
10 17ec669c65c401e5e85875cf2962eb7d8c47595f ima-ng sha256:dc6b013e9768d9b13bcd6678470448090138ca831f4771a43ce3988d8e54ffce /lib/ld-linux-aarch64.so.1
10 58679a66ac1de17f02595625a8fbeafa259a4c81 ima-ng sha256:494f62bcfb2fcf1b427d5092fafa62c8df39a83b4a64402620b28846724f237f /usr/lib/libtirpc.so.3.0.0
10 42f74ee200434576e33be153830b3d55bbe6d2bf ima-ng sha256:a18856b4f6927bc2b8dd4608c0768b8f98544a161b85bf4a64419131243ad300 /lib/libresolv.so.2
10 626b4f7bd4f123d18d3a3d8719ed0ae19ee5f331 ima-ng sha256:b8d442de5d31c3f9d1bbb98785f04d4a23dc53442b286d85d4b355927cbe9af4 /lib/libc.so.6
10 655a200869696207646377a58cab417fd35b09d2 ima-ng sha256:ad46146b6dd32b47213e5327f1bb2f962ef838a4b707ef7445fa2dbc9019b44f /etc/inittab
10 81353202685e022fcd0069a3b2fc4eaa6b1db537 ima-ng sha256:74d698fe0a6862050af29083aa591c960ec1f67be960047e96bb6be5fc2bc0c0 /bin/mount
10 ae64184ee607ef8f3aa08ab52cb548318534fd4b ima-ng sha256:27846b57e8234c6a9611b00351f581a54ad6f9a1920b9aa18ceb0ae28e4f7564 /lib/libmount.so.1.1.0
10 5ea01f34e7705d1bdb936fd576e2aeb5fd78dab9 ima-ng sha256:3d2a414ec0355fcf0910224fb4a3c53e13d98731a35241edfdf4fb911ed9b210 /lib/libblkid.so.1.1.0
10 22c48b4853594a08a73ad4ae6dbe6f2c2bebc6c5 ima-ng sha256:e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855 /run/utmp
10 3024ea5021f8a5d9fb4bd519d599bdca43b7fb93 ima-ng sha256:71ea9ffe2b30e5a9bdceff78785cf281cc41544474db8dc4605a06a597ce1edc /etc/fstab
10 2e7530a0f56420991ac7611734cea4774b92b9ef ima-ng sha256:df4697d699442cfe73db7cc8b4c1b37e8a31e75e01f66a0d70134ac812fa683b /bin/mkdir
10 3ad117a863aa1ed7b7c09e1d106f84abf7d2ae96 ima-ng sha256:c19a710989b43222431b02399273dba409fe10ca8eefff88eaa936fa695f8324 /bin/ln
10 4141c82cb516ac3c846e0b08abcd6abeee7efa1a ima-ng sha256:b75d7f28772f71715a941c77e07e3922815391dd9cc5718ad21f2231c2da09bb /etc/hostname
10 dfcedd3c7dc3ed42e09219804504489ab264e2e3 ima-ng sha256:dc1615df9f2012b20b81ffad8e07e16293039ba7fd897854ca3646d6cfea0c0f /etc/init.d/rcS
...
2. ima_policy=critical_data
# cat /sys/kernel/security/ima/ascii_runtime_measurements
10 0adefe762c149c7cec19da62f0da1297fcfbffff ima-ng sha256:0000000000000000000000000000000000000000000000000000000000000000 boot_aggregate
10 49ab61dd97ea2f759edcb6c6a3387ac67f0aa576 ima-buf sha256:0c907aab3261194f16b0c2a422a82f145bc9b9ecb8fdb633fa43e3e5379f0af2 kernel_version 372e312e302d7263312b // Ignorable since it's generated by ima_init(_core)().
10 4e5d73ebadfd8f850cb93ce4de755ba148a9a7d5 ima-ng sha256:0000000000000000000000000000000000000000000000000000000000000000 boot_aggregate_late
Therefore, init_ima() could move into late_initcall_sync like v1 did:
- https://lore.kernel.org/all/20260417175759.3191279-2-yeoreum.yun@arm.com/
Thanks.
--
Sincerely,
Yeoreum Yun
^ permalink raw reply
* Re: (subset) [PATCH v3 00/14] Remove redundant rcu_read_lock/unlock() in spin_lock
From: Jeff Johnson @ 2026-04-30 21:30 UTC (permalink / raw)
To: tj, tony.luck, jani.nikula, ap420073, jv, freude, bcrl, trondmy,
longman, kees, pengdonglin
Cc: bigeasy, hdanton, paulmck, linux-kernel, linux-rt-devel,
linux-nfs, linux-aio, linux-fsdevel, linux-security-module,
netdev, intel-gfx, linux-wireless, linux-acpi, linux-s390,
cgroups
In-Reply-To: <20250916044735.2316171-1-dolinux.peng@gmail.com>
On Tue, 16 Sep 2025 12:47:21 +0800, pengdonglin wrote:
> Since commit a8bb74acd8efe ("rcu: Consolidate RCU-sched update-side function definitions")
> there is no difference between rcu_read_lock(), rcu_read_lock_bh() and
> rcu_read_lock_sched() in terms of RCU read section and the relevant grace
> period. That means that spin_lock(), which implies rcu_read_lock_sched(),
> also implies rcu_read_lock().
>
> There is no need no explicitly start a RCU read section if one has already
> been started implicitly by spin_lock().
>
> [...]
Applied, thanks!
[14/14] wifi: ath9k: Remove redundant rcu_read_lock/unlock() in spin_lock
commit: c4f518736472c8cfbf1d304e01c631babd2bbf34
Best regards,
--
Jeff Johnson <jeff.johnson@oss.qualcomm.com>
^ permalink raw reply
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