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* Re: AVC denied for docker while trying to set labels for tmpfs mounts
From: Daniel Walsh @ 2021-07-22  9:38 UTC (permalink / raw)
  To: Sujithra P, Paul Moore; +Cc: linux-security-module, selinux
In-Reply-To: <CAP198X-7NZ+1QfYK3cUUkMMNoaJTwNzBN8wr27egWT1kVh=g3Q@mail.gmail.com>

On 7/21/21 18:17, Sujithra P wrote:
> Thanks Paul!
>
> Is there any specific centos/RH mailing list that I can ask? Not sure
> whether it is a problem with kernel/docker/kubelet.
> semodule -R seems to fix the problem, but not sure what is causing the
> loaded policy to get corrupt.
> Any insight on how to figure this out would be very much appreciated.
>
> Thanks
> Sujithra.
I am guessing that one of the containers is loading policy.  You should 
be able to see something in the auditlog, about a policy load.
> On Wed, Jul 21, 2021 at 2:01 PM Paul Moore <paul@paul-moore.com> wrote:
>> On Wed, Jul 21, 2021 at 2:46 PM Sujithra P <sujithrap@gmail.com> wrote:
>>> Hi SELinux Experts,
>>>
>>> The following issue is described in the below post as well.
>>> https://github.com/containers/container-selinux/issues/141
>>>
>>> Occasionally running into the following selinux denials for docker
>>>
>>> type=AVC msg=audit(1626732057.636:4583): avc:  denied  { associate }
>>> for  pid=57450 comm="dockerd" name="/" dev="tmpfs" ino=150014
>>> scontext=system_u:object_r:container_file_t:s0:c263,c914
>>> tcontext=system_u:object_r:lib_t:s0 tclass=filesystem permissive=0
>>>
>>> type=AVC msg=audit(1626812823.170:9434): avc:  denied  { associate }
>>> for  pid=20027 comm="dockerd" name="/" dev="tmpfs" ino=198147
>>> scontext=system_u:object_r:container_file_t:s0:c578,c672
>>> tcontext=system_u:object_r:locale_t:s0 tclass=filesystem permissive=0
>>>
>>>
>>>   level=error msg="Handler for POST
>>> /v1.40/containers/a3a875e7896384e3bff53b8317e91ed4301a13957f42187eb227f28e09bd877c/start
>>> returned error: error setting label on mount source
>>> '/var/lib/kubelet/pods/f7cee5b2-bcd9-4aa1-9d67-c75b677ba2a1/volumes/kubernetes.io~secret/secret':
>>> failed to set file label on
>>> /var/lib/kubelet/pods/f7cee5b2-bcd9-4aa1-9d67-c75b677ba2a1/volumes/kubernetes.io~secret/secret:
>>> permission denied"
>>>
>>>
>>> Docker is not able to set labels for these tmpfs mounts because they
>>> end up having wrong labels when they are created (sometimes
>>> "locale_t", sometimes "lib_t" which of course is not the
>>> default/correct context for tmpfs fs).
>>> Apparently semodule -R and deleting these tmps files or reboot of the
>>> node fixes the problem.
>>> Not sure what is causing the tmpfs mounts to get wrong labels in the
>>> first place.
>>>
>>> Everything seems to be fine to begin with, but as the system keeps
>>> scheduling pods on the node, this behavior is observed sometimes (not
>>> consistent always).
>>>
>>>
>>> OS Details:
>>>
>>> NAME="CentOS Linux"
>>> VERSION="8 (Core)"
>>> ID="centos"
>>> ID_LIKE="rhel fedora"
>>> VERSION_ID="8"
>>> PLATFORM_ID="platform:el8"
>>> PRETTY_NAME="CentOS Linux 8 (Core)"
>>>
>>> Docker Version:
>>> Client: Docker Engine - Community
>>> Version: 19.03.13
>>> API version: 1.40
>>> Go version: go1.13.15
>>> Git commit: 4484c46d9d
>>> Built: Wed Sep 16 17:02:36 2020
>>> OS/Arch: linux/amd64
>>> Experimental: false
>>>
>>> Kubernetes Version*
>>> v1.20.8-gke.1500
>>>
>>>
>>> Any help on how to debug this issue  would be greatly appreciated.
>> This sounds like it might be a problem with CentOS and/or your Docker
>> install, have you tried talking with the RH/CentOS folks about this
>> problem?  We focus mostly on upstream issues here and it isn't clear
>> to me at this moment that this is an upstream issue.
>>
>> --
>> paul moore
>> www.paul-moore.com



^ permalink raw reply

* [RFC PATCH v1 2/4] dm: crypt: use new key_extract_material helper
From: Ahmad Fatoum @ 2021-07-22  9:18 UTC (permalink / raw)
  To: David Howells, Jarkko Sakkinen, James Morris, Serge E. Hallyn,
	Alasdair Kergon, Mike Snitzer, dm-devel, Song Liu,
	Richard Weinberger
  Cc: kernel, Ahmad Fatoum, linux-kernel, linux-raid, keyrings,
	linux-mtd, linux-security-module, linux-integrity
In-Reply-To: <cover.b2fdd70b830d12853b12a12e32ceb0c8162c1346.1626945419.git-series.a.fatoum@pengutronix.de>

There is a common function now to extract key material out of a few
different key types, which includes all types currently supported by
dm-crypt. Make use of it.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
To: David Howells <dhowells@redhat.com>
To: Jarkko Sakkinen <jarkko@kernel.org>
To: James Morris <jmorris@namei.org>
To: "Serge E. Hallyn" <serge@hallyn.com>
To: Alasdair Kergon <agk@redhat.com>
To: Mike Snitzer <snitzer@redhat.com>
To: dm-devel@redhat.com
To: Song Liu <song@kernel.org>
To: Richard Weinberger <richard@nod.at>
Cc: linux-kernel@vger.kernel.org
Cc: linux-raid@vger.kernel.org
Cc: keyrings@vger.kernel.org
Cc: linux-mtd@lists.infradead.org
Cc: linux-security-module@vger.kernel.org
Cc: linux-integrity@vger.kernel.org
---
 drivers/md/dm-crypt.c | 65 ++++++--------------------------------------
 1 file changed, 9 insertions(+), 56 deletions(-)

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 50f4cbd600d5..576d6b7ce231 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -2421,61 +2421,14 @@ static bool contains_whitespace(const char *str)
 	return false;
 }
 
-static int set_key_user(struct crypt_config *cc, struct key *key)
-{
-	const struct user_key_payload *ukp;
-
-	ukp = user_key_payload_locked(key);
-	if (!ukp)
-		return -EKEYREVOKED;
-
-	if (cc->key_size != ukp->datalen)
-		return -EINVAL;
-
-	memcpy(cc->key, ukp->data, cc->key_size);
-
-	return 0;
-}
-
-static int set_key_encrypted(struct crypt_config *cc, struct key *key)
-{
-	const struct encrypted_key_payload *ekp;
-
-	ekp = key->payload.data[0];
-	if (!ekp)
-		return -EKEYREVOKED;
-
-	if (cc->key_size != ekp->decrypted_datalen)
-		return -EINVAL;
-
-	memcpy(cc->key, ekp->decrypted_data, cc->key_size);
-
-	return 0;
-}
-
-static int set_key_trusted(struct crypt_config *cc, struct key *key)
-{
-	const struct trusted_key_payload *tkp;
-
-	tkp = key->payload.data[0];
-	if (!tkp)
-		return -EKEYREVOKED;
-
-	if (cc->key_size != tkp->key_len)
-		return -EINVAL;
-
-	memcpy(cc->key, tkp->key, cc->key_size);
-
-	return 0;
-}
-
 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
 {
 	char *new_key_string, *key_desc;
 	int ret;
+	unsigned int len;
 	struct key_type *type;
 	struct key *key;
-	int (*set_key)(struct crypt_config *cc, struct key *key);
+	const void *key_material;
 
 	/*
 	 * Reject key_string with whitespace. dm core currently lacks code for
@@ -2493,18 +2446,14 @@ static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string
 
 	if (!strncmp(key_string, "logon:", key_desc - key_string + 1)) {
 		type = &key_type_logon;
-		set_key = set_key_user;
 	} else if (!strncmp(key_string, "user:", key_desc - key_string + 1)) {
 		type = &key_type_user;
-		set_key = set_key_user;
 	} else if (IS_ENABLED(CONFIG_ENCRYPTED_KEYS) &&
 		   !strncmp(key_string, "encrypted:", key_desc - key_string + 1)) {
 		type = &key_type_encrypted;
-		set_key = set_key_encrypted;
 	} else if (IS_ENABLED(CONFIG_TRUSTED_KEYS) &&
 	           !strncmp(key_string, "trusted:", key_desc - key_string + 1)) {
 		type = &key_type_trusted;
-		set_key = set_key_trusted;
 	} else {
 		return -EINVAL;
 	}
@@ -2521,14 +2470,18 @@ static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string
 
 	down_read(&key->sem);
 
-	ret = set_key(cc, key);
-	if (ret < 0) {
+	key_material = key_extract_material(key, &len);
+	if (!IS_ERR(key_material) && len != cc->key_size)
+		key_material = ERR_PTR(-EINVAL);
+	if (IS_ERR(key_material)) {
 		up_read(&key->sem);
 		key_put(key);
 		kfree_sensitive(new_key_string);
-		return ret;
+		return PTR_ERR(key_material);
 	}
 
+	memcpy(cc->key, key_material, len);
+
 	up_read(&key->sem);
 	key_put(key);
 
-- 
git-series 0.9.1

^ permalink raw reply related

* [RFC PATCH v1 1/4] keys: introduce key_extract_material helper
From: Ahmad Fatoum @ 2021-07-22  9:17 UTC (permalink / raw)
  To: David Howells, Jarkko Sakkinen, James Morris, Serge E. Hallyn,
	Alasdair Kergon, Mike Snitzer, dm-devel, Song Liu,
	Richard Weinberger
  Cc: kernel, Ahmad Fatoum, linux-kernel, linux-raid, keyrings,
	linux-mtd, linux-security-module, linux-integrity
In-Reply-To: <cover.b2fdd70b830d12853b12a12e32ceb0c8162c1346.1626945419.git-series.a.fatoum@pengutronix.de>

While keys of differing type have a common struct key definition, there is
no common scheme to the payload and key material extraction differs.

For kernel functionality that supports different key types,
this means duplicated code for key material extraction and because key type
is discriminated by a pointer to a global, users need to replicate
reachability checks as well, so builtin code doesn't depend on a key
type symbol offered by a module.

Make this easier by adding a common helper with initial support for
user, logon, encrypted and trusted keys. The code is taken from
dm-crypt, which is migrated to use the helper in a later commit.

The implementation must be partially in a header to support configurations
where the key type symbol is defined in a module, but key support in general
is built-in.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
I am not sure whether the chosen header and source file are the best
places for this. This could be made header-only too if that's preferred.

To: David Howells <dhowells@redhat.com>
To: Jarkko Sakkinen <jarkko@kernel.org>
To: James Morris <jmorris@namei.org>
To: "Serge E. Hallyn" <serge@hallyn.com>
To: Alasdair Kergon <agk@redhat.com>
To: Mike Snitzer <snitzer@redhat.com>
To: dm-devel@redhat.com
To: Song Liu <song@kernel.org>
To: Richard Weinberger <richard@nod.at>
Cc: linux-kernel@vger.kernel.org
Cc: linux-raid@vger.kernel.org
Cc: keyrings@vger.kernel.org
Cc: linux-mtd@lists.infradead.org
Cc: linux-security-module@vger.kernel.org
Cc: linux-integrity@vger.kernel.org
---
 include/linux/key.h | 45 +++++++++++++++++++++++++++++++++++++++++++++
 security/keys/key.c | 40 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 85 insertions(+)

diff --git a/include/linux/key.h b/include/linux/key.h
index 7febc4881363..916612f5b313 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -20,6 +20,8 @@
 #include <linux/assoc_array.h>
 #include <linux/refcount.h>
 #include <linux/time64.h>
+#include <linux/err.h>
+#include <linux/kconfig.h>
 
 #ifdef __KERNEL__
 #include <linux/uidgid.h>
@@ -487,6 +489,48 @@ extern void key_fsuid_changed(struct cred *new_cred);
 extern void key_fsgid_changed(struct cred *new_cred);
 extern void key_init(void);
 
+/*
+ * internal use, so key core code need not link against
+ * all supported key types
+ * */
+enum __key_type {
+	KEY_TYPE_UNKNOWN, KEY_TYPE_USER, KEY_TYPE_ENCRYPTED, KEY_TYPE_TRUSTED
+};
+
+const void *__key_extract_material(const struct key *key, enum __key_type type,
+				   unsigned int *len);
+
+/**
+ * key_extract_material - Extract decrypted data out of a key
+ * @key: a logon, user, encrypted or trusted key
+ * @len: pointer to variable to store key size into
+ *
+ * Extract decrypted data out of supported key types
+ *
+ * Returns a pointer to the key material if successfull or an error
+ * pointer if key type is not compiled in, the buffer is too
+ * small or the key was revoked.
+ */
+static inline const void *key_extract_material(const struct key *key,
+					       unsigned int *len)
+{
+	extern struct key_type key_type_user;
+	extern struct key_type key_type_logon;
+	extern struct key_type key_type_encrypted;
+	extern struct key_type key_type_trusted;
+	enum __key_type type = KEY_TYPE_UNKNOWN;
+	const struct key_type *t = key->type;
+
+	if (t == &key_type_logon || t == &key_type_user)
+		type = KEY_TYPE_USER;
+	else if (IS_REACHABLE(CONFIG_ENCRYPTED_KEYS) && t == &key_type_encrypted)
+		type = KEY_TYPE_ENCRYPTED;
+	else if (IS_REACHABLE(CONFIG_TRUSTED_KEYS) && t == &key_type_trusted)
+		type = KEY_TYPE_TRUSTED;
+
+	return __key_extract_material(key, type, len);
+}
+
 #else /* CONFIG_KEYS */
 
 #define key_validate(k)			0
@@ -504,6 +548,7 @@ extern void key_init(void);
 #define key_init()			do { } while(0)
 #define key_free_user_ns(ns)		do { } while(0)
 #define key_remove_domain(d)		do { } while(0)
+#define key_extract_material(k, l)	ERR_PTR(-EINVAL)
 
 #endif /* CONFIG_KEYS */
 #endif /* __KERNEL__ */
diff --git a/security/keys/key.c b/security/keys/key.c
index c45afdd1dfbb..69cd1cb8c413 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -15,6 +15,9 @@
 #include <linux/random.h>
 #include <linux/ima.h>
 #include <linux/err.h>
+#include <keys/user-type.h>
+#include <keys/encrypted-type.h>
+#include <keys/trusted-type.h>
 #include "internal.h"
 
 struct kmem_cache *key_jar;
@@ -1140,6 +1143,43 @@ int generic_key_instantiate(struct key *key, struct key_preparsed_payload *prep)
 }
 EXPORT_SYMBOL(generic_key_instantiate);
 
+const void *__key_extract_material(const struct key *key,
+				   enum __key_type type, unsigned int *len)
+{
+	const struct encrypted_key_payload *ekp;
+	const struct trusted_key_payload *tkp;
+	const struct user_key_payload *ukp;
+
+	switch (type) {
+	case KEY_TYPE_USER:
+		ukp = user_key_payload_locked(key);
+		if (!ukp)
+			break;
+
+		*len = ukp->datalen;
+		return ukp->data;
+	case KEY_TYPE_ENCRYPTED:
+		ekp = key->payload.data[0];
+		if (!ekp)
+			break;
+
+		*len = ekp->decrypted_datalen;
+		return ekp->decrypted_data;
+	case KEY_TYPE_TRUSTED:
+		tkp = key->payload.data[0];
+		if (!tkp)
+			break;
+
+		*len = tkp->key_len;
+		return tkp->key;
+	default:
+		return ERR_PTR(-EINVAL);
+	}
+
+	return ERR_PTR(-EKEYREVOKED);
+}
+EXPORT_SYMBOL(__key_extract_material);
+
 /**
  * register_key_type - Register a type of key.
  * @ktype: The new key type.
-- 
git-series 0.9.1

^ permalink raw reply related

* [RFC PATCH v1 4/4] ubifs: auth: consult encrypted and trusted keys if no logon key was found
From: Ahmad Fatoum @ 2021-07-22  9:18 UTC (permalink / raw)
  To: David Howells, Jarkko Sakkinen, James Morris, Serge E. Hallyn,
	Alasdair Kergon, Mike Snitzer, dm-devel, Song Liu,
	Richard Weinberger, Jonathan Corbet
  Cc: kernel, Ahmad Fatoum, linux-kernel, linux-doc, linux-raid,
	keyrings, linux-mtd, linux-security-module, linux-integrity
In-Reply-To: <cover.b2fdd70b830d12853b12a12e32ceb0c8162c1346.1626945419.git-series.a.fatoum@pengutronix.de>

Currently, UBIFS auth_key can only be a logon key: This is a user key
that's provided to the kernel in plaintext and that then remains within
the kernel. Linux also supports trusted and encrypted keys, which have
stronger guarantees: They are only exposed to userspace in encrypted
form and, in the case of trusted keys, can be directly rooted to a trust
source like a TPM chip.

Add support for auth_key to be either a logon, encrypted or trusted key.
At mount time, the keyring will be searched for a key with the supplied
name in that order.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
To: David Howells <dhowells@redhat.com>
To: Jarkko Sakkinen <jarkko@kernel.org>
To: James Morris <jmorris@namei.org>
To: "Serge E. Hallyn" <serge@hallyn.com>
To: Alasdair Kergon <agk@redhat.com>
To: Mike Snitzer <snitzer@redhat.com>
To: dm-devel@redhat.com
To: Song Liu <song@kernel.org>
To: Richard Weinberger <richard@nod.at>
To: Jonathan Corbet <corbet@lwn.net>
Cc: linux-kernel@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-raid@vger.kernel.org
Cc: keyrings@vger.kernel.org
Cc: linux-mtd@lists.infradead.org
Cc: linux-security-module@vger.kernel.org
Cc: linux-integrity@vger.kernel.org
---
 Documentation/filesystems/ubifs.rst |  2 +-
 fs/ubifs/auth.c                     | 19 ++++++++++++-------
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/Documentation/filesystems/ubifs.rst b/Documentation/filesystems/ubifs.rst
index e6ee99762534..12d08458b3d7 100644
--- a/Documentation/filesystems/ubifs.rst
+++ b/Documentation/filesystems/ubifs.rst
@@ -101,7 +101,7 @@ compr=zlib              override default compressor and set it to "zlib"
 auth_key=		specify the key used for authenticating the filesystem.
 			Passing this option makes authentication mandatory.
 			The passed key must be present in the kernel keyring
-			and must be of type 'logon'
+			and must be of type 'logon', 'encrypted' or 'trusted'.
 auth_hash_name=		The hash algorithm used for authentication. Used for
 			both hashing and for creating HMACs. Typical values
 			include "sha256" or "sha512"
diff --git a/fs/ubifs/auth.c b/fs/ubifs/auth.c
index 6a0b8d858d81..af8e9eb58a60 100644
--- a/fs/ubifs/auth.c
+++ b/fs/ubifs/auth.c
@@ -14,6 +14,8 @@
 #include <crypto/hash.h>
 #include <crypto/algapi.h>
 #include <keys/user-type.h>
+#include <keys/trusted-type.h>
+#include <keys/encrypted-type.h>
 #include <keys/asymmetric-type.h>
 
 #include "ubifs.h"
@@ -256,9 +258,10 @@ out_destroy:
 int ubifs_init_authentication(struct ubifs_info *c)
 {
 	struct key *keyring_key;
-	const struct user_key_payload *ukp;
 	int err;
+	unsigned int len;
 	char hmac_name[CRYPTO_MAX_ALG_NAME];
+	const void *key_material;
 
 	if (!c->auth_hash_name) {
 		ubifs_err(c, "authentication hash name needed with authentication");
@@ -277,6 +280,10 @@ int ubifs_init_authentication(struct ubifs_info *c)
 		 c->auth_hash_name);
 
 	keyring_key = request_key(&key_type_logon, c->auth_key_name, NULL);
+	if (IS_ERR(keyring_key) && IS_REACHABLE(CONFIG_ENCRYPTED_KEYS))
+		keyring_key = request_key(&key_type_encrypted, c->auth_key_name, NULL);
+	if (IS_ERR(keyring_key) && IS_REACHABLE(CONFIG_TRUSTED_KEYS))
+		keyring_key = request_key(&key_type_trusted, c->auth_key_name, NULL);
 
 	if (IS_ERR(keyring_key)) {
 		ubifs_err(c, "Failed to request key: %ld",
@@ -286,12 +293,10 @@ int ubifs_init_authentication(struct ubifs_info *c)
 
 	down_read(&keyring_key->sem);
 
-	ukp = user_key_payload_locked(keyring_key);
-	if (!ukp) {
-		/* key was revoked before we acquired its semaphore */
-		err = -EKEYREVOKED;
+	key_material = key_extract_material(keyring_key, &len);
+	err = PTR_ERR_OR_ZERO(key_material);
+	if (err < 0)
 		goto out;
-	}
 
 	c->hash_tfm = crypto_alloc_shash(c->auth_hash_name, 0, 0);
 	if (IS_ERR(c->hash_tfm)) {
@@ -324,7 +329,7 @@ int ubifs_init_authentication(struct ubifs_info *c)
 		goto out_free_hmac;
 	}
 
-	err = crypto_shash_setkey(c->hmac_tfm, ukp->data, ukp->datalen);
+	err = crypto_shash_setkey(c->hmac_tfm, key_material, len);
 	if (err)
 		goto out_free_hmac;
 
-- 
git-series 0.9.1

^ permalink raw reply related

* [RFC PATCH v1 0/4] keys: introduce key_extract_material helper
From: Ahmad Fatoum @ 2021-07-22  9:17 UTC (permalink / raw)
  To: David Howells, Jarkko Sakkinen, James Morris, Serge E. Hallyn,
	Alasdair Kergon, Mike Snitzer, dm-devel, Song Liu,
	Richard Weinberger
  Cc: kernel, linux-kernel, linux-raid, linux-integrity, keyrings,
	linux-mtd, linux-security-module

While keys of differing type have a common struct key definition, there is
no common scheme to the payload and key material extraction differs.

For kernel functionality that supports different key types,
this means duplicated code for key material extraction and because key type
is discriminated by a pointer to a global, users need to replicate
reachability checks as well, so builtin code doesn't depend on a key
type symbol offered by a module.

Make this easier by adding a common helper with initial support for
user, logon, encrypted and trusted keys.

This series contains two example of its use: dm-crypt uses it to reduce
boilerplate and ubifs authentication uses it to gain support for trusted
and encrypted keys alongside the already supported logon keys.

Looking forward to your feedback,
Ahmad

---
To: David Howells <dhowells@redhat.com>
To: Jarkko Sakkinen <jarkko@kernel.org>
To: James Morris <jmorris@namei.org>
To: "Serge E. Hallyn" <serge@hallyn.com>
To: Alasdair Kergon <agk@redhat.com>
To: Mike Snitzer <snitzer@redhat.com>
To: dm-devel@redhat.com
To: Song Liu <song@kernel.org>
To: Richard Weinberger <richard@nod.at>
Cc: linux-kernel@vger.kernel.org
Cc: linux-raid@vger.kernel.org
Cc: linux-integrity@vger.kernel.org
Cc: keyrings@vger.kernel.org
Cc: linux-mtd@lists.infradead.org
Cc: linux-security-module@vger.kernel.org

Ahmad Fatoum (4):
  keys: introduce key_extract_material helper
  dm: crypt: use new key_extract_material helper
  ubifs: auth: remove never hit key type error check
  ubifs: auth: consult encrypted and trusted keys if no logon key was found

 Documentation/filesystems/ubifs.rst |  2 +-
 drivers/md/dm-crypt.c               | 65 ++++--------------------------
 fs/ubifs/auth.c                     | 25 +++++-------
 include/linux/key.h                 | 45 +++++++++++++++++++++-
 security/keys/key.c                 | 40 ++++++++++++++++++-
 5 files changed, 107 insertions(+), 70 deletions(-)

base-commit: 2734d6c1b1a089fb593ef6a23d4b70903526fe0c
-- 
git-series 0.9.1

^ permalink raw reply

* [RFC PATCH v1 3/4] ubifs: auth: remove never hit key type error check
From: Ahmad Fatoum @ 2021-07-22  9:18 UTC (permalink / raw)
  To: David Howells, Jarkko Sakkinen, James Morris, Serge E. Hallyn,
	Alasdair Kergon, Mike Snitzer, dm-devel, Song Liu,
	Richard Weinberger
  Cc: kernel, Ahmad Fatoum, linux-kernel, linux-raid, keyrings,
	linux-mtd, linux-security-module, linux-integrity
In-Reply-To: <cover.b2fdd70b830d12853b12a12e32ceb0c8162c1346.1626945419.git-series.a.fatoum@pengutronix.de>

key_request accepts a key type as its first argument. If it returns a
valid pointer, it should always have this same requested key type.

Indeed other request_key users surveyed such as dm-crypt, ecryptfs
and fscrypt v1 also don't check the key type. Therefore drop the
apparently unneeded check.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
To: David Howells <dhowells@redhat.com>
To: Jarkko Sakkinen <jarkko@kernel.org>
To: James Morris <jmorris@namei.org>
To: "Serge E. Hallyn" <serge@hallyn.com>
To: Alasdair Kergon <agk@redhat.com>
To: Mike Snitzer <snitzer@redhat.com>
To: dm-devel@redhat.com
To: Song Liu <song@kernel.org>
To: Richard Weinberger <richard@nod.at>
Cc: linux-kernel@vger.kernel.org
Cc: linux-raid@vger.kernel.org
Cc: keyrings@vger.kernel.org
Cc: linux-mtd@lists.infradead.org
Cc: linux-security-module@vger.kernel.org
Cc: linux-integrity@vger.kernel.org
---
 fs/ubifs/auth.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/fs/ubifs/auth.c b/fs/ubifs/auth.c
index e564d5ff8781..6a0b8d858d81 100644
--- a/fs/ubifs/auth.c
+++ b/fs/ubifs/auth.c
@@ -286,12 +286,6 @@ int ubifs_init_authentication(struct ubifs_info *c)
 
 	down_read(&keyring_key->sem);
 
-	if (keyring_key->type != &key_type_logon) {
-		ubifs_err(c, "key type must be logon");
-		err = -ENOKEY;
-		goto out;
-	}
-
 	ukp = user_key_payload_locked(keyring_key);
 	if (!ukp) {
 		/* key was revoked before we acquired its semaphore */
-- 
git-series 0.9.1

^ permalink raw reply related

* Re: [PATCH RFC 0/9] sk_buff: optimize layout for GRO
From: Paolo Abeni @ 2021-07-22  7:10 UTC (permalink / raw)
  To: Casey Schaufler, netdev
  Cc: David S. Miller, Jakub Kicinski, Florian Westphal, Eric Dumazet,
	linux-security-module, selinux
In-Reply-To: <1252ad17-3460-5e6a-8f0d-05d91a1a7b96@schaufler-ca.com>

Hello,

On Wed, 2021-07-21 at 11:15 -0700, Casey Schaufler wrote:
> On 7/21/2021 9:44 AM, Paolo Abeni wrote:
> > This is a very early draft - in a different world would be
> > replaced by hallway discussion at in-person conference - aimed at
> > outlining some ideas and collect feedback on the overall outlook.
> > There are still bugs to be fixed, more test and benchmark need, etc.
> > 
> > There are 3 main goals:
> > - [try to] avoid the overhead for uncommon conditions at GRO time
> >   (patches 1-4)
> > - enable backpressure for the veth GRO path (patches 5-6)
> > - reduce the number of cacheline used by the sk_buff lifecycle
> >   from 4 to 3, at least in some common scenarios (patches 1,7-9).
> >   The idea here is avoid the initialization of some fields and
> >   control their validity with a bitmask, as presented by at least
> >   Florian and Jesper in the past.
> 
> If I understand correctly, you're creating an optimized case
> which excludes ct, secmark, vlan and UDP tunnel. Is this correct,
> and if so, why those particular fields? What impact will this have
> in the non-optimal (with any of the excluded fields) case?

Thank you for the feedback.

There are 2 different relevant points:

- the GRO stage.
  packets carring any of CT, dst, sk or skb_ext will do 2 additional
conditionals per gro_receive WRT the current code. My understanding is
that having any of such field set at GRO receive time is quite
exceptional for real nic. All others packet will do 4 or 5 less
conditionals, and will traverse a little less code.

- sk_buff lifecycle
  * packets carrying vlan and UDP will not see any differences: sk_buff
lifecycle will stil use 4 cachelines, as currently does, and no
additional conditional is introduced.
  * packets carring nfct or secmark will see an additional conditional
every time such field is accessed. The number of cacheline used will
still be 4, as in the current code. My understanding is that when such
access happens, there is already a relevant amount of "additional" code
to be executed, the conditional overhead should not be measurable.

Cheers,

Paolo


^ permalink raw reply

* Re: [PATCH 2/4] KEYS: trusted: allow trust sources to use kernel RNG for key material
From: Sumit Garg @ 2021-07-22  6:31 UTC (permalink / raw)
  To: Ahmad Fatoum
  Cc: James Bottomley, Jarkko Sakkinen, Mimi Zohar, David Howells,
	kernel, James Morris, Serge E. Hallyn, Horia Geantă,
	Aymen Sghaier, Herbert Xu, David S. Miller, Udit Agarwal,
	Eric Biggers, Jan Luebbe, David Gstir, Richard Weinberger,
	Franck LENORMAND, open list:ASYMMETRIC KEYS,
	open list:HARDWARE RANDOM NUMBER GENERATOR CORE, linux-integrity,
	Linux Kernel Mailing List, open list:SECURITY SUBSYSTEM
In-Reply-To: <7b771da7b09a01c8b4da2ed21f05251ea797b2e8.1626885907.git-series.a.fatoum@pengutronix.de>

On Wed, 21 Jul 2021 at 22:19, Ahmad Fatoum <a.fatoum@pengutronix.de> wrote:
>
> The two existing trusted key sources don't make use of the kernel RNG,
> but instead let the hardware that does the sealing/unsealing also
> generate the random key material. While a previous change offers users
> the choice to use the kernel RNG instead for both, new trust sources
> may want to unconditionally use the kernel RNG for generating key
> material, like it's done elsewhere in the kernel.
>
> This is especially prudent for hardware that has proven-in-production
> HWRNG drivers implemented, as otherwise code would have to be duplicated
> only to arrive at a possibly worse result.
>
> Make this possible by turning struct trusted_key_ops::get_random
> into an optional member. If a driver leaves it NULL, kernel RNG
> will be used instead.
>
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> ---
> To: James Bottomley <jejb@linux.ibm.com>
> To: Jarkko Sakkinen <jarkko@kernel.org>
> To: Mimi Zohar <zohar@linux.ibm.com>
> To: David Howells <dhowells@redhat.com>
> Cc: James Morris <jmorris@namei.org>
> Cc: "Serge E. Hallyn" <serge@hallyn.com>
> Cc: "Horia Geantă" <horia.geanta@nxp.com>
> Cc: Aymen Sghaier <aymen.sghaier@nxp.com>
> Cc: Herbert Xu <herbert@gondor.apana.org.au>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Udit Agarwal <udit.agarwal@nxp.com>
> Cc: Eric Biggers <ebiggers@kernel.org>
> Cc: Jan Luebbe <j.luebbe@pengutronix.de>
> Cc: David Gstir <david@sigma-star.at>
> Cc: Richard Weinberger <richard@nod.at>
> Cc: Franck LENORMAND <franck.lenormand@nxp.com>
> Cc: Sumit Garg <sumit.garg@linaro.org>
> Cc: keyrings@vger.kernel.org
> Cc: linux-crypto@vger.kernel.org
> Cc: linux-integrity@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-security-module@vger.kernel.org
> ---
>  include/keys/trusted-type.h               | 2 +-
>  security/keys/trusted-keys/trusted_core.c | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h
> index d89fa2579ac0..4eb64548a74f 100644
> --- a/include/keys/trusted-type.h
> +++ b/include/keys/trusted-type.h
> @@ -64,7 +64,7 @@ struct trusted_key_ops {
>         /* Unseal a key. */
>         int (*unseal)(struct trusted_key_payload *p, char *datablob);
>
> -       /* Get a randomized key. */
> +       /* Optional: Get a randomized key. */
>         int (*get_random)(unsigned char *key, size_t key_len);
>
>         /* Exit key interface. */
> diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c
> index 569af9af8df0..d2b7626cde8b 100644
> --- a/security/keys/trusted-keys/trusted_core.c
> +++ b/security/keys/trusted-keys/trusted_core.c
> @@ -334,7 +334,7 @@ static int __init init_trusted(void)
>                         continue;
>
>                 get_random = trusted_key_sources[i].ops->get_random;
> -               if (trusted_kernel_rng)
> +               if (trusted_kernel_rng || !get_random)
>                         get_random = kernel_get_random;
>

For ease of understanding, I would prefer to write it as:

                  get_random = trusted_key_sources[i].ops->get_random ?:
                                         kernel_get_random;
                  if (trusted_kernel_rng)
                        get_random = kernel_get_random;

With that:

Acked-by: Sumit Garg <sumit.garg@linaro.org>

-Sumit

>                 static_call_update(trusted_key_init,
> --
> git-series 0.9.1

^ permalink raw reply

* Re: [PATCH 1/4] KEYS: trusted: allow users to use kernel RNG for key material
From: Sumit Garg @ 2021-07-22  6:17 UTC (permalink / raw)
  To: Ahmad Fatoum
  Cc: James Bottomley, Jarkko Sakkinen, Mimi Zohar, David Howells,
	kernel, James Morris, Serge E. Hallyn, Horia Geantă,
	Aymen Sghaier, Herbert Xu, David S. Miller, Udit Agarwal,
	Jan Luebbe, Eric Biggers, David Gstir, Richard Weinberger,
	Franck LENORMAND, open list:ASYMMETRIC KEYS,
	open list:HARDWARE RANDOM NUMBER GENERATOR CORE, linux-integrity,
	Linux Kernel Mailing List, open list:SECURITY SUBSYSTEM
In-Reply-To: <3b93fda0155af1a8776e9cc9984ecdb39ce827e4.1626885907.git-series.a.fatoum@pengutronix.de>

On Wed, 21 Jul 2021 at 22:19, Ahmad Fatoum <a.fatoum@pengutronix.de> wrote:
>
> The two existing trusted key sources don't make use of the kernel RNG,
> but instead let the hardware doing the sealing/unsealing also
> generate the random key material. However, Users may want to place
> less trust into the quality of the trust source's random number
> generator and instead use the kernel entropy pool, which can be
> seeded from multiple entropy sources.
>
> Make this possible by adding a new trusted.kernel_rng parameter,
> that will force use of the kernel RNG. In its absence, it's up
> to the trust source to decide, which random numbers to use,
> maintaining the existing behavior.
>
> Suggested-by: Jarkko Sakkinen <jarkko@kernel.org>
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> ---
> To: James Bottomley <jejb@linux.ibm.com>
> To: Jarkko Sakkinen <jarkko@kernel.org>
> To: Mimi Zohar <zohar@linux.ibm.com>
> To: David Howells <dhowells@redhat.com>
> Cc: James Morris <jmorris@namei.org>
> Cc: "Serge E. Hallyn" <serge@hallyn.com>
> Cc: "Horia Geantă" <horia.geanta@nxp.com>
> Cc: Aymen Sghaier <aymen.sghaier@nxp.com>
> Cc: Herbert Xu <herbert@gondor.apana.org.au>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Udit Agarwal <udit.agarwal@nxp.com>
> Cc: Jan Luebbe <j.luebbe@pengutronix.de>
> Cc: Eric Biggers <ebiggers@kernel.org>
> Cc: David Gstir <david@sigma-star.at>
> Cc: Richard Weinberger <richard@nod.at>
> Cc: Franck LENORMAND <franck.lenormand@nxp.com>
> Cc: Sumit Garg <sumit.garg@linaro.org>
> Cc: keyrings@vger.kernel.org
> Cc: linux-crypto@vger.kernel.org
> Cc: linux-integrity@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-security-module@vger.kernel.org
> ---
>  Documentation/admin-guide/kernel-parameters.txt   |  7 ++++++-
>  Documentation/security/keys/trusted-encrypted.rst | 20 +++++++++-------
>  security/keys/trusted-keys/trusted_core.c         | 17 +++++++++++++-
>  3 files changed, 35 insertions(+), 9 deletions(-)
>

Sounds like a reasonable approach to me.

Acked-by: Sumit Garg <sumit.garg@linaro.org>

-Sumit

> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index bdb22006f713..0267ead88902 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -5734,6 +5734,13 @@
>                         first trust source as a backend which is initialized
>                         successfully during iteration.
>
> +       trusted.kernel_rng =    [KEYS]
> +                       Format: <bool>
> +                       When set to true (1), the kernel random number pool
> +                       is used to generate key material for trusted keys.
> +                       The default is to leave the RNG's choice to each
> +                       individual trust source.
> +
>         tsc=            Disable clocksource stability checks for TSC.
>                         Format: <string>
>                         [x86] reliable: mark tsc clocksource as reliable, this
> diff --git a/Documentation/security/keys/trusted-encrypted.rst b/Documentation/security/keys/trusted-encrypted.rst
> index 80d5a5af62a1..1d4b4b8f12f0 100644
> --- a/Documentation/security/keys/trusted-encrypted.rst
> +++ b/Documentation/security/keys/trusted-encrypted.rst
> @@ -87,22 +87,26 @@ Key Generation
>  Trusted Keys
>  ------------
>
> -New keys are created from random numbers generated in the trust source. They
> -are encrypted/decrypted using a child key in the storage key hierarchy.
> -Encryption and decryption of the child key must be protected by a strong
> -access control policy within the trust source.
> +New keys are created from random numbers. They are encrypted/decrypted using
> +a child key in the storage key hierarchy. Encryption and decryption of the
> +child key must be protected by a strong access control policy within the
> +trust source. The random number generator in use differs according to the
> +selected trust source:
>
> -  *  TPM (hardware device) based RNG
> +  *  TPM: hardware device based RNG
>
> -     Strength of random numbers may vary from one device manufacturer to
> -     another.
> +     Keys are generated within the TPM. Strength of random numbers may vary
> +     from one device manufacturer to another.
>
> -  *  TEE (OP-TEE based on Arm TrustZone) based RNG
> +  *  TEE: OP-TEE based on Arm TrustZone based RNG
>
>       RNG is customizable as per platform needs. It can either be direct output
>       from platform specific hardware RNG or a software based Fortuna CSPRNG
>       which can be seeded via multiple entropy sources.
>
> +Optionally, users may specify ``trusted.kernel_rng=1`` on the kernel
> +command-line to override the used RNG with the kernel's random number pool.
> +
>  Encrypted Keys
>  --------------
>
> diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c
> index 8cab69e5d0da..569af9af8df0 100644
> --- a/security/keys/trusted-keys/trusted_core.c
> +++ b/security/keys/trusted-keys/trusted_core.c
> @@ -16,12 +16,17 @@
>  #include <linux/key-type.h>
>  #include <linux/module.h>
>  #include <linux/parser.h>
> +#include <linux/random.h>
>  #include <linux/rcupdate.h>
>  #include <linux/slab.h>
>  #include <linux/static_call.h>
>  #include <linux/string.h>
>  #include <linux/uaccess.h>
>
> +static bool trusted_kernel_rng;
> +module_param_named(kernel_rng, trusted_kernel_rng, bool, 0);
> +MODULE_PARM_DESC(kernel_rng, "Generate key material from kernel RNG");
> +
>  static char *trusted_key_source;
>  module_param_named(source, trusted_key_source, charp, 0);
>  MODULE_PARM_DESC(source, "Select trusted keys source (tpm or tee)");
> @@ -312,8 +317,14 @@ struct key_type key_type_trusted = {
>  };
>  EXPORT_SYMBOL_GPL(key_type_trusted);
>
> +static int kernel_get_random(unsigned char *key, size_t key_len)
> +{
> +       return get_random_bytes_wait(key, key_len) ?: key_len;
> +}
> +
>  static int __init init_trusted(void)
>  {
> +       int (*get_random)(unsigned char *key, size_t key_len);
>         int i, ret = 0;
>
>         for (i = 0; i < ARRAY_SIZE(trusted_key_sources); i++) {
> @@ -322,6 +333,10 @@ static int __init init_trusted(void)
>                             strlen(trusted_key_sources[i].name)))
>                         continue;
>
> +               get_random = trusted_key_sources[i].ops->get_random;
> +               if (trusted_kernel_rng)
> +                       get_random = kernel_get_random;
> +
>                 static_call_update(trusted_key_init,
>                                    trusted_key_sources[i].ops->init);
>                 static_call_update(trusted_key_seal,
> @@ -329,7 +344,7 @@ static int __init init_trusted(void)
>                 static_call_update(trusted_key_unseal,
>                                    trusted_key_sources[i].ops->unseal);
>                 static_call_update(trusted_key_get_random,
> -                                  trusted_key_sources[i].ops->get_random);
> +                                  get_random);
>                 static_call_update(trusted_key_exit,
>                                    trusted_key_sources[i].ops->exit);
>                 migratable = trusted_key_sources[i].ops->migratable;
> --
> git-series 0.9.1

^ permalink raw reply

* Re: [PATCH v2] KEYS: trusted: fix use as module when CONFIG_TCG_TPM=m
From: Sumit Garg @ 2021-07-22  4:46 UTC (permalink / raw)
  To: Ahmad Fatoum
  Cc: Jarkko Sakkinen, James Morris, Serge E. Hallyn, James Bottomley,
	Mimi Zohar, David Howells, Herbert Xu, David S. Miller, kernel,
	Andreas Rammhold, David Gstir, Richard Weinberger,
	open list:ASYMMETRIC KEYS,
	open list:HARDWARE RANDOM NUMBER GENERATOR CORE,
	Linux Kernel Mailing List, open list:SECURITY SUBSYSTEM,
	linux-integrity
In-Reply-To: <20210721160258.7024-1-a.fatoum@pengutronix.de>

On Wed, 21 Jul 2021 at 21:34, Ahmad Fatoum <a.fatoum@pengutronix.de> wrote:
>
> Since commit 5d0682be3189 ("KEYS: trusted: Add generic trusted keys
> framework"), trusted.ko built with CONFIG_TCG_TPM=CONFIG_TRUSTED_KEYS=m
> will not register the TPM trusted key type at runtime.
>
> This is because, after that rework, CONFIG_DEPENDENCY of the TPM
> and TEE backends were checked with #ifdef, but that's only true
> when they're built-in.
>
> Fix this by introducing two new boolean Kconfig symbols:
> TRUSTED_KEYS_TPM and TRUSTED_KEYS_TEE with the appropriate
> dependencies and use them to check which backends are available.
>
> This also has a positive effect on user experience:
>
>  - It's now possible to use TEE trusted keys without CONFIG_TCG_TPM
>  - It's now possible to enable CONFIG_TCG_TPM, but exclude TPM from
>    available trust sources
>  - TEE=m && TRUSTED_KEYS=y no longer leads to TEE support
>    being silently dropped
>
> Any code depending on the TPM trusted key backend or symbols exported
> by it will now need to explicitly state that it
>
>   depends on TRUSTED_KEYS && TRUSTED_KEYS_TPM
>
> The latter to ensure the dependency is built and the former to ensure
> it's reachable for module builds. This currently only affects
> CONFIG_ASYMMETRIC_TPM_KEY_SUBTYPE, so it's fixed up here as well.
>
> Reported-by: Andreas Rammhold <andreas@rammhold.de>
> Fixes: 5d0682be3189 ("KEYS: trusted: Add generic trusted keys framework")
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> ---
>
> (Implicit) v1 was as a preparatory patch for CAAM trusted keys[1] with the
> goal of fixing the Kconfig inflexibility after the TEE trusted key rework.
>
> Unbeknownst to me, it also fixes a regression, which was later
> reported by Andreas[2] along with a patch.
>
> I split out the fix from the CAAM series and adjusted the commit
> message to explain the regression.
>
> v1 -> v2:
>   - Move rest of TPM-related selects from TRUSTED_KEYS to
>     TRUSTED_KEYS_TPM (Sumit)
>   - Remove left-over line in Makefile (Sumit)
>   - added Fixes: tag
>   - adjust commit message to reference the regression reported
>     by Andreas
>   - have ASYMMETRIC_TPM_KEY_SUBTYPE depend on TRUSTED_KEYS_TPM,
>     because it references global symbols that are exported
>     by the trusted key TPM backend.
>
> [1]: https://lore.kernel.org/linux-integrity/f8285eb0135ba30c9d846cf9dd395d1f5f8b1efc.1624364386.git-series.a.fatoum@pengutronix.de/
> [2]: https://lore.kernel.org/linux-integrity/20210719091335.vwfebcpkf4pag3wm@wrt/T/#t
>
> To: Jarkko Sakkinen <jarkko@kernel.org>
> To: James Morris <jmorris@namei.org>
> To: "Serge E. Hallyn" <serge@hallyn.com>
> To: James Bottomley <jejb@linux.ibm.com>
> To: Mimi Zohar <zohar@linux.ibm.com>
> To: Sumit Garg <sumit.garg@linaro.org>
> To: David Howells <dhowells@redhat.com>
> To: Herbert Xu <herbert@gondor.apana.org.au>
> To: "David S. Miller" <davem@davemloft.net>
> Cc: David Gstir <david@sigma-star.at>
> Cc: Richard Weinberger <richard@nod.at>
> Cc: keyrings@vger.kernel.org
> Cc: linux-crypto@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-security-module@vger.kernel.org
> Cc: linux-integrity@vger.kernel.org
> ---
>  crypto/asymmetric_keys/Kconfig            |  2 +-
>  security/keys/Kconfig                     | 18 ++++++--------
>  security/keys/trusted-keys/Kconfig        | 29 +++++++++++++++++++++++
>  security/keys/trusted-keys/Makefile       |  8 +++----
>  security/keys/trusted-keys/trusted_core.c |  4 ++--
>  5 files changed, 43 insertions(+), 18 deletions(-)
>  create mode 100644 security/keys/trusted-keys/Kconfig
>

Looks good to me apart from the minor comment below. With that fixed:

Reviewed-by: Sumit Garg <sumit.garg@linaro.org>

> diff --git a/crypto/asymmetric_keys/Kconfig b/crypto/asymmetric_keys/Kconfig
> index 1f1f004dc757..8886eddbf881 100644
> --- a/crypto/asymmetric_keys/Kconfig
> +++ b/crypto/asymmetric_keys/Kconfig
> @@ -25,7 +25,7 @@ config ASYMMETRIC_PUBLIC_KEY_SUBTYPE
>  config ASYMMETRIC_TPM_KEY_SUBTYPE
>         tristate "Asymmetric TPM backed private key subtype"
>         depends on TCG_TPM
> -       depends on TRUSTED_KEYS
> +       depends on TRUSTED_KEYS && TRUSTED_KEYS_TPM
>         select CRYPTO_HMAC
>         select CRYPTO_SHA1
>         select CRYPTO_HASH_INFO
> diff --git a/security/keys/Kconfig b/security/keys/Kconfig
> index 64b81abd087e..9ec302962fe2 100644
> --- a/security/keys/Kconfig
> +++ b/security/keys/Kconfig
> @@ -70,23 +70,19 @@ config BIG_KEYS
>
>  config TRUSTED_KEYS
>         tristate "TRUSTED KEYS"
> -       depends on KEYS && TCG_TPM
> -       select CRYPTO
> -       select CRYPTO_HMAC
> -       select CRYPTO_SHA1
> -       select CRYPTO_HASH_INFO
> -       select ASN1_ENCODER
> -       select OID_REGISTRY
> -       select ASN1
> +       depends on KEYS
>         help
>           This option provides support for creating, sealing, and unsealing
>           keys in the kernel. Trusted keys are random number symmetric keys,
> -         generated and RSA-sealed by the TPM. The TPM only unseals the keys,
> -         if the boot PCRs and other criteria match.  Userspace will only ever
> -         see encrypted blobs.
> +         generated and sealed by a trust source selected at kernel boot-time.
> +         Userspace will only ever see encrypted blobs.
>
>           If you are unsure as to whether this is required, answer N.
>
> +if TRUSTED_KEYS
> +source "security/keys/trusted-keys/Kconfig"
> +endif
> +
>  config ENCRYPTED_KEYS
>         tristate "ENCRYPTED KEYS"
>         depends on KEYS
> diff --git a/security/keys/trusted-keys/Kconfig b/security/keys/trusted-keys/Kconfig
> new file mode 100644
> index 000000000000..c163cfeedff6
> --- /dev/null
> +++ b/security/keys/trusted-keys/Kconfig
> @@ -0,0 +1,29 @@
> +config TRUSTED_KEYS_TPM
> +       bool "TPM-based trusted keys"
> +       depends on TCG_TPM >= TRUSTED_KEYS
> +       default y
> +       select CRYPTO
> +       select CRYPTO_HMAC
> +       select CRYPTO_SHA1
> +       select CRYPTO_HASH_INFO
> +       select ASN1_ENCODER
> +       select OID_REGISTRY
> +       select ASN1
> +       help
> +         Enable use of the Trusted Platform Module (TPM) as trusted key
> +         backend. Trusted keys are are random number symmetric keys,

s/are are/are/

-Sumit

> +         which will be generated and RSA-sealed by the TPM.
> +         The TPM only unseals the keys, if the boot PCRs and other
> +         criteria match.
> +
> +config TRUSTED_KEYS_TEE
> +       bool "TEE-based trusted keys"
> +       depends on TEE >= TRUSTED_KEYS
> +       default y
> +       help
> +         Enable use of the Trusted Execution Environment (TEE) as trusted
> +         key backend.
> +
> +if !TRUSTED_KEYS_TPM && !TRUSTED_KEYS_TEE
> +comment "No trust source selected!"
> +endif
> diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile
> index feb8b6c3cc79..2e2371eae4d5 100644
> --- a/security/keys/trusted-keys/Makefile
> +++ b/security/keys/trusted-keys/Makefile
> @@ -5,10 +5,10 @@
>
>  obj-$(CONFIG_TRUSTED_KEYS) += trusted.o
>  trusted-y += trusted_core.o
> -trusted-y += trusted_tpm1.o
> +trusted-$(CONFIG_TRUSTED_KEYS_TPM) += trusted_tpm1.o
>
>  $(obj)/trusted_tpm2.o: $(obj)/tpm2key.asn1.h
> -trusted-y += trusted_tpm2.o
> -trusted-y += tpm2key.asn1.o
> +trusted-$(CONFIG_TRUSTED_KEYS_TPM) += trusted_tpm2.o
> +trusted-$(CONFIG_TRUSTED_KEYS_TPM) += tpm2key.asn1.o
>
> -trusted-$(CONFIG_TEE) += trusted_tee.o
> +trusted-$(CONFIG_TRUSTED_KEYS_TEE) += trusted_tee.o
> diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c
> index d5c891d8d353..8cab69e5d0da 100644
> --- a/security/keys/trusted-keys/trusted_core.c
> +++ b/security/keys/trusted-keys/trusted_core.c
> @@ -27,10 +27,10 @@ module_param_named(source, trusted_key_source, charp, 0);
>  MODULE_PARM_DESC(source, "Select trusted keys source (tpm or tee)");
>
>  static const struct trusted_key_source trusted_key_sources[] = {
> -#if defined(CONFIG_TCG_TPM)
> +#if defined(CONFIG_TRUSTED_KEYS_TPM)
>         { "tpm", &trusted_key_tpm_ops },
>  #endif
> -#if defined(CONFIG_TEE)
> +#if defined(CONFIG_TRUSTED_KEYS_TEE)
>         { "tee", &trusted_key_tee_ops },
>  #endif
>  };
> --
> 2.30.2
>

^ permalink raw reply

* [PATCH v28 25/25] AppArmor: Remove the exclusive flag
From: Casey Schaufler @ 2021-07-22  0:47 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel, paul,
	sds, linux-kernel
In-Reply-To: <20210722004758.12371-1-casey@schaufler-ca.com>

With the inclusion of the interface LSM process attribute
mechanism AppArmor no longer needs to be treated as an
"exclusive" security module. Remove the flag that indicates
it is exclusive. Remove the stub getpeersec_dgram AppArmor
hook as it has no effect in the single LSM case and
interferes in the multiple LSM case.

Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 security/apparmor/lsm.c | 20 +-------------------
 1 file changed, 1 insertion(+), 19 deletions(-)

diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 65a004597e53..15af5a5cb0c0 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -1138,22 +1138,6 @@ static int apparmor_socket_getpeersec_stream(struct socket *sock,
 	return error;
 }
 
-/**
- * apparmor_socket_getpeersec_dgram - get security label of packet
- * @sock: the peer socket
- * @skb: packet data
- * @secid: pointer to where to put the secid of the packet
- *
- * Sets the netlabel socket state on sk from parent
- */
-static int apparmor_socket_getpeersec_dgram(struct socket *sock,
-					    struct sk_buff *skb, u32 *secid)
-
-{
-	/* TODO: requires secid support */
-	return -ENOPROTOOPT;
-}
-
 /**
  * apparmor_sock_graft - Initialize newly created socket
  * @sk: child sock
@@ -1257,8 +1241,6 @@ static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
 #endif
 	LSM_HOOK_INIT(socket_getpeersec_stream,
 		      apparmor_socket_getpeersec_stream),
-	LSM_HOOK_INIT(socket_getpeersec_dgram,
-		      apparmor_socket_getpeersec_dgram),
 	LSM_HOOK_INIT(sock_graft, apparmor_sock_graft),
 #ifdef CONFIG_NETWORK_SECMARK
 	LSM_HOOK_INIT(inet_conn_request, apparmor_inet_conn_request),
@@ -1928,7 +1910,7 @@ static int __init apparmor_init(void)
 
 DEFINE_LSM(apparmor) = {
 	.name = "apparmor",
-	.flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
+	.flags = LSM_FLAG_LEGACY_MAJOR,
 	.enabled = &apparmor_enabled,
 	.blobs = &apparmor_blob_sizes,
 	.init = apparmor_init,
-- 
2.31.1


^ permalink raw reply related

* [PATCH v28 24/25] LSM: Add /proc attr entry for full LSM context
From: Casey Schaufler @ 2021-07-22  0:47 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel, paul,
	sds, linux-kernel, linux-api, linux-doc
In-Reply-To: <20210722004758.12371-1-casey@schaufler-ca.com>

Add an entry /proc/.../attr/context which displays the full
process security "context" in compound format:
        lsm1\0value\0lsm2\0value\0...
This entry is not writable.

A security module may decide that its policy does not allow
this information to be displayed. In this case none of the
information will be displayed.

Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: linux-api@vger.kernel.org
Cc: linux-doc@vger.kernel.org
---
 Documentation/ABI/testing/procfs-attr-context | 14 ++++
 Documentation/security/lsm.rst                | 14 ++++
 fs/proc/base.c                                |  1 +
 include/linux/lsm_hooks.h                     |  6 ++
 security/apparmor/include/procattr.h          |  2 +-
 security/apparmor/lsm.c                       |  8 +-
 security/apparmor/procattr.c                  | 22 +++---
 security/security.c                           | 79 +++++++++++++++++++
 security/selinux/hooks.c                      |  2 +-
 security/smack/smack_lsm.c                    |  2 +-
 10 files changed, 135 insertions(+), 15 deletions(-)
 create mode 100644 Documentation/ABI/testing/procfs-attr-context

diff --git a/Documentation/ABI/testing/procfs-attr-context b/Documentation/ABI/testing/procfs-attr-context
new file mode 100644
index 000000000000..40da1c397c30
--- /dev/null
+++ b/Documentation/ABI/testing/procfs-attr-context
@@ -0,0 +1,14 @@
+What:		/proc/*/attr/context
+Contact:	linux-security-module@vger.kernel.org,
+Description:	The current security information used by all Linux
+		security module (LSMs) that are active on the system.
+		The details of permissions required to read from
+		this interface and hence obtain the security state
+		of the task identified is dependent on the LSMs that
+		are active on the system.
+		A process cannot write to this interface.
+		The data provided by this interface will have the form:
+			lsm_name\0lsm_data\0[lsm_name\0lsm_data\0]...
+		where lsm_name is the name of the LSM and the following
+		lsm_data is the process data for that LSM.
+Users:		LSM user-space
diff --git a/Documentation/security/lsm.rst b/Documentation/security/lsm.rst
index b77b4a540391..070225ae6ceb 100644
--- a/Documentation/security/lsm.rst
+++ b/Documentation/security/lsm.rst
@@ -143,3 +143,17 @@ separated list of the active security modules.
 The file ``/proc/pid/attr/interface_lsm`` contains the name of the security
 module for which the ``/proc/pid/attr/current`` interface will
 apply. This interface can be written to.
+
+The infrastructure does provide an interface for the special
+case where multiple security modules provide a process context.
+This is provided in compound context format.
+
+-  `lsm\0value\0lsm\0value\0`
+
+The `lsm` and `value` fields are NUL-terminated bytestrings.
+Each field may contain whitespace or non-printable characters.
+The NUL bytes are included in the size of a compound context.
+The context ``Bell\0Secret\0Biba\0Loose\0`` has a size of 23.
+
+The file ``/proc/pid/attr/context`` provides the security
+context of the identified process.
diff --git a/fs/proc/base.c b/fs/proc/base.c
index f80ed1c40053..387627fd8313 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2821,6 +2821,7 @@ static const struct pid_entry attr_dir_stuff[] = {
 	ATTR(NULL, "keycreate",		0666),
 	ATTR(NULL, "sockcreate",	0666),
 	ATTR(NULL, "interface_lsm",	0666),
+	ATTR(NULL, "context",		0444),
 #ifdef CONFIG_SECURITY_SMACK
 	DIR("smack",			0555,
 	    proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index d2c4bc94d47f..f6ffe8b069e2 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1397,6 +1397,12 @@
  *	@pages contains the number of pages.
  *	Return 0 if permission is granted.
  *
+ * @getprocattr:
+ *	Provide the named process attribute for display in special files in
+ *	the /proc/.../attr directory.  Attribute naming and the data displayed
+ *	is at the discretion of the security modules.  The exception is the
+ *	"context" attribute, which will contain the security context of the
+ *	task as a nul terminated text string without trailing whitespace.
  * @ismaclabel:
  *	Check if the extended attribute specified by @name
  *	represents a MAC label. Returns 1 if name is a MAC
diff --git a/security/apparmor/include/procattr.h b/security/apparmor/include/procattr.h
index 31689437e0e1..03dbfdb2f2c0 100644
--- a/security/apparmor/include/procattr.h
+++ b/security/apparmor/include/procattr.h
@@ -11,7 +11,7 @@
 #ifndef __AA_PROCATTR_H
 #define __AA_PROCATTR_H
 
-int aa_getprocattr(struct aa_label *label, char **string);
+int aa_getprocattr(struct aa_label *label, char **string, bool newline);
 int aa_setprocattr_changehat(char *args, size_t size, int flags);
 
 #endif /* __AA_PROCATTR_H */
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 4237536106aa..65a004597e53 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -602,6 +602,7 @@ static int apparmor_getprocattr(struct task_struct *task, char *name,
 	const struct cred *cred = get_task_cred(task);
 	struct aa_task_ctx *ctx = task_ctx(current);
 	struct aa_label *label = NULL;
+	bool newline = true;
 
 	if (strcmp(name, "current") == 0)
 		label = aa_get_newest_label(cred_label(cred));
@@ -609,11 +610,14 @@ static int apparmor_getprocattr(struct task_struct *task, char *name,
 		label = aa_get_newest_label(ctx->previous);
 	else if (strcmp(name, "exec") == 0 && ctx->onexec)
 		label = aa_get_newest_label(ctx->onexec);
-	else
+	else if (strcmp(name, "context") == 0) {
+		label = aa_get_newest_label(cred_label(cred));
+		newline = false;
+	} else
 		error = -EINVAL;
 
 	if (label)
-		error = aa_getprocattr(label, value);
+		error = aa_getprocattr(label, value, newline);
 
 	aa_put_label(label);
 	put_cred(cred);
diff --git a/security/apparmor/procattr.c b/security/apparmor/procattr.c
index c929bf4a3df1..be3b083d9b74 100644
--- a/security/apparmor/procattr.c
+++ b/security/apparmor/procattr.c
@@ -20,6 +20,7 @@
  * aa_getprocattr - Return the profile information for @profile
  * @profile: the profile to print profile info about  (NOT NULL)
  * @string: Returns - string containing the profile info (NOT NULL)
+ * @newline: Should a newline be added to @string.
  *
  * Returns: length of @string on success else error on failure
  *
@@ -30,20 +31,21 @@
  *
  * Returns: size of string placed in @string else error code on failure
  */
-int aa_getprocattr(struct aa_label *label, char **string)
+int aa_getprocattr(struct aa_label *label, char **string, bool newline)
 {
 	struct aa_ns *ns = labels_ns(label);
 	struct aa_ns *current_ns = aa_get_current_ns();
+	int flags = FLAG_VIEW_SUBNS | FLAG_HIDDEN_UNCONFINED;
 	int len;
 
 	if (!aa_ns_visible(current_ns, ns, true)) {
 		aa_put_ns(current_ns);
 		return -EACCES;
 	}
+	if (newline)
+		flags |= FLAG_SHOW_MODE;
 
-	len = aa_label_snxprint(NULL, 0, current_ns, label,
-				FLAG_SHOW_MODE | FLAG_VIEW_SUBNS |
-				FLAG_HIDDEN_UNCONFINED);
+	len = aa_label_snxprint(NULL, 0, current_ns, label, flags);
 	AA_BUG(len < 0);
 
 	*string = kmalloc(len + 2, GFP_KERNEL);
@@ -52,19 +54,19 @@ int aa_getprocattr(struct aa_label *label, char **string)
 		return -ENOMEM;
 	}
 
-	len = aa_label_snxprint(*string, len + 2, current_ns, label,
-				FLAG_SHOW_MODE | FLAG_VIEW_SUBNS |
-				FLAG_HIDDEN_UNCONFINED);
+	len = aa_label_snxprint(*string, len + 2, current_ns, label, flags);
 	if (len < 0) {
 		aa_put_ns(current_ns);
 		return len;
 	}
 
-	(*string)[len] = '\n';
-	(*string)[len + 1] = 0;
+	if (newline) {
+		(*string)[len] = '\n';
+		(*string)[++len] = 0;
+	}
 
 	aa_put_ns(current_ns);
-	return len + 1;
+	return len;
 }
 
 /**
diff --git a/security/security.c b/security/security.c
index 5d7fd982f84a..4572da4e27f7 100644
--- a/security/security.c
+++ b/security/security.c
@@ -801,6 +801,57 @@ static int lsm_superblock_alloc(struct super_block *sb)
 	return 0;
 }
 
+/**
+ * append_ctx - append a lsm/context pair to a compound context
+ * @ctx: the existing compound context
+ * @ctxlen: size of the old context, including terminating nul byte
+ * @lsm: new lsm name, nul terminated
+ * @new: new context, possibly nul terminated
+ * @newlen: maximum size of @new
+ *
+ * replace @ctx with a new compound context, appending @newlsm and @new
+ * to @ctx. On exit the new data replaces the old, which is freed.
+ * @ctxlen is set to the new size, which includes a trailing nul byte.
+ *
+ * Returns 0 on success, -ENOMEM if no memory is available.
+ */
+static int append_ctx(char **ctx, int *ctxlen, const char *lsm, char *new,
+		      int newlen)
+{
+	char *final;
+	size_t llen;
+	size_t nlen;
+	size_t flen;
+
+	llen = strlen(lsm) + 1;
+	/*
+	 * A security module may or may not provide a trailing nul on
+	 * when returning a security context. There is no definition
+	 * of which it should be, and there are modules that do it
+	 * each way.
+	 */
+	nlen = strnlen(new, newlen);
+
+	flen = *ctxlen + llen + nlen + 1;
+	final = kzalloc(flen, GFP_KERNEL);
+
+	if (final == NULL)
+		return -ENOMEM;
+
+	if (*ctxlen)
+		memcpy(final, *ctx, *ctxlen);
+
+	memcpy(final + *ctxlen, lsm, llen);
+	memcpy(final + *ctxlen + llen, new, nlen);
+
+	kfree(*ctx);
+
+	*ctx = final;
+	*ctxlen = flen;
+
+	return 0;
+}
+
 /*
  * The default value of the LSM hook is defined in linux/lsm_hook_defs.h and
  * can be accessed with:
@@ -2234,6 +2285,10 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
 				char **value)
 {
 	struct security_hook_list *hp;
+	char *final = NULL;
+	char *cp;
+	int rc = 0;
+	int finallen = 0;
 	int ilsm = lsm_task_ilsm(current);
 	int slot = 0;
 
@@ -2261,6 +2316,30 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
 		return -ENOMEM;
 	}
 
+	if (!strcmp(name, "context")) {
+		hlist_for_each_entry(hp, &security_hook_heads.getprocattr,
+				     list) {
+			rc = hp->hook.getprocattr(p, "context", &cp);
+			if (rc == -EINVAL)
+				continue;
+			if (rc < 0) {
+				kfree(final);
+				return rc;
+			}
+			rc = append_ctx(&final, &finallen, hp->lsmid->lsm,
+					cp, rc);
+			kfree(cp);
+			if (rc < 0) {
+				kfree(final);
+				return rc;
+			}
+		}
+		if (final == NULL)
+			return -EINVAL;
+		*value = final;
+		return finallen;
+	}
+
 	hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) {
 		if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm))
 			continue;
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 12ae311b7275..046570556e5a 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6458,7 +6458,7 @@ static int selinux_getprocattr(struct task_struct *p,
 			goto bad;
 	}
 
-	if (!strcmp(name, "current"))
+	if (!strcmp(name, "current") || !strcmp(name, "context"))
 		sid = __tsec->sid;
 	else if (!strcmp(name, "prev"))
 		sid = __tsec->osid;
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index e65497a5c095..1618d7d6154b 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3477,7 +3477,7 @@ static int smack_getprocattr(struct task_struct *p, char *name, char **value)
 	char *cp;
 	int slen;
 
-	if (strcmp(name, "current") != 0)
+	if (strcmp(name, "current") != 0 && strcmp(name, "context") != 0)
 		return -EINVAL;
 
 	cp = kstrdup(skp->smk_known, GFP_KERNEL);
-- 
2.31.1


^ permalink raw reply related

* [PATCH v28 23/25] Audit: Add record for multiple object LSM attributes
From: Casey Schaufler @ 2021-07-22  0:47 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel, paul,
	sds, linux-kernel
In-Reply-To: <20210722004758.12371-1-casey@schaufler-ca.com>

Create a new audit record type to contain the object information
when there are multiple security modules that may require such data.
This record is linked with the same timestamp and serial number.

An example of the MAC_OBJ_CONTEXTS (1421) record is:

        type=UNKNOWN[1421]
        msg=audit(1601152467.009:1050):
        obj_selinux="unconfined_u:object_r:user_home_t:s0"

Not all security modules that can provide object information
do so in all cases. It is possible that a security module won't
apply an object attribute in all cases.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: linux-audit@redhat.com
To: Paul Moore <paul@paul-moore.com>
---
 include/linux/audit.h      |  7 ++++
 include/uapi/linux/audit.h |  1 +
 kernel/audit.c             | 54 ++++++++++++++++++++++++++++
 kernel/audit.h             |  4 +--
 kernel/auditsc.c           | 73 +++++++-------------------------------
 5 files changed, 76 insertions(+), 63 deletions(-)

diff --git a/include/linux/audit.h b/include/linux/audit.h
index 85eb87f6f92d..6bf0c86fcbc9 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -187,6 +187,8 @@ extern void		    audit_log_path_denied(int type,
 extern void		    audit_log_lost(const char *message);
 
 extern int audit_log_task_context(struct audit_buffer *ab);
+extern int audit_log_object_context(struct audit_buffer *ab,
+				    struct lsmblob *blob);
 extern void audit_log_task_info(struct audit_buffer *ab);
 
 extern int		    audit_update_lsm_rules(void);
@@ -250,6 +252,11 @@ static inline int audit_log_task_context(struct audit_buffer *ab)
 {
 	return 0;
 }
+static inline int audit_log_object_context(struct audit_buffer *ab,
+					   struct lsmblob *blob)
+{
+	return 0;
+}
 static inline void audit_log_task_info(struct audit_buffer *ab)
 { }
 
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index 4432a8bed8e0..4efed1abcd54 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -140,6 +140,7 @@
 #define AUDIT_MAC_CALIPSO_ADD	1418	/* NetLabel: add CALIPSO DOI entry */
 #define AUDIT_MAC_CALIPSO_DEL	1419	/* NetLabel: del CALIPSO DOI entry */
 #define AUDIT_MAC_TASK_CONTEXTS	1420	/* Multiple LSM contexts */
+#define AUDIT_MAC_OBJ_CONTEXTS	1421	/* Multiple LSM object contexts */
 
 #define AUDIT_FIRST_KERN_ANOM_MSG   1700
 #define AUDIT_LAST_KERN_ANOM_MSG    1799
diff --git a/kernel/audit.c b/kernel/audit.c
index cba63789a164..c500b303e39f 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -2204,6 +2204,60 @@ int audit_log_task_context(struct audit_buffer *ab)
 }
 EXPORT_SYMBOL(audit_log_task_context);
 
+int audit_log_object_context(struct audit_buffer *ab,
+				    struct lsmblob *blob)
+{
+	int i;
+	int error;
+	bool sep = false;
+	struct lsmcontext lsmdata;
+	struct audit_buffer *lsmab = NULL;
+	struct audit_context *context = NULL;
+
+	/*
+	 * If there is more than one security module that has a
+	 * object "context" it's necessary to put the object data
+	 * into a separate record to maintain compatibility.
+	 */
+	if (lsm_multiple_contexts()) {
+		audit_log_format(ab, " obj=?");
+		context = ab->ctx;
+		if (context)
+			lsmab = audit_log_start(context, GFP_KERNEL,
+						AUDIT_MAC_OBJ_CONTEXTS);
+		WARN_ONCE(!context, "Context not set for object\n");
+	}
+
+	for (i = 0; i < LSMBLOB_ENTRIES; i++) {
+		if (blob->secid[i] == 0)
+			continue;
+		error = security_secid_to_secctx(blob, &lsmdata, i);
+		if (error && error != -EINVAL) {
+			audit_panic("error in audit_log_object_context");
+			return error;
+		}
+
+		if (context) {
+			audit_log_format(lsmab, "%sobj_%s=\"%s\"",
+					 sep ? " " : "",
+					 lsm_slot_to_name(i),
+					 lsmdata.context);
+			sep = true;
+		} else
+			audit_log_format(ab, " obj=%s", lsmdata.context);
+
+		security_release_secctx(&lsmdata);
+		if (!context)
+			break;
+	}
+
+	if (context)
+		audit_log_end(lsmab);
+
+	return 0;
+}
+EXPORT_SYMBOL(audit_log_object_context);
+
 void audit_log_d_path_exe(struct audit_buffer *ab,
 			  struct mm_struct *mm)
 {
diff --git a/kernel/audit.h b/kernel/audit.h
index ddc1a69edc79..d62f3cb09278 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -78,7 +78,7 @@ struct audit_names {
 	kuid_t			uid;
 	kgid_t			gid;
 	dev_t			rdev;
-	u32			osid;
+	struct lsmblob		oblob;
 	struct audit_cap_data	fcap;
 	unsigned int		fcap_ver;
 	unsigned char		type;		/* record type */
@@ -153,7 +153,7 @@ struct audit_context {
 			kuid_t			uid;
 			kgid_t			gid;
 			umode_t			mode;
-			u32			osid;
+			struct lsmblob		oblob;
 			int			has_perm;
 			uid_t			perm_uid;
 			gid_t			perm_gid;
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 01fdcbf468c0..5261a69a050a 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -691,14 +691,6 @@ static int audit_filter_rules(struct task_struct *tsk,
 			if (f->lsm_isset) {
 				/* Find files that match */
 				if (name) {
-					/*
-					 * lsmblob_init sets all values in the
-					 * lsmblob to sid. This is temporary
-					 * until name->osid is converted to a
-					 * lsmblob, which happens later in
-					 * this patch set.
-					 */
-					lsmblob_init(&blob, name->osid);
 					result = security_audit_rule_match(
 								&blob,
 								f->type,
@@ -706,7 +698,6 @@ static int audit_filter_rules(struct task_struct *tsk,
 								f->lsm_rules);
 				} else if (ctx) {
 					list_for_each_entry(n, &ctx->names_list, list) {
-						lsmblob_init(&blob, name->osid);
 						if (security_audit_rule_match(
 								&blob,
 								f->type,
@@ -720,8 +711,7 @@ static int audit_filter_rules(struct task_struct *tsk,
 				/* Find ipc objects that match */
 				if (!ctx || ctx->type != AUDIT_IPC)
 					break;
-				lsmblob_init(&blob, ctx->ipc.osid);
-				if (security_audit_rule_match(&blob,
+				if (security_audit_rule_match(&ctx->ipc.oblob,
 							      f->type, f->op,
 							      f->lsm_rules))
 					++result;
@@ -1031,7 +1021,6 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
 				 struct lsmblob *blob, char *comm)
 {
 	struct audit_buffer *ab;
-	struct lsmcontext lsmctx;
 	int rc = 0;
 
 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
@@ -1041,15 +1030,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
 	audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid,
 			 from_kuid(&init_user_ns, auid),
 			 from_kuid(&init_user_ns, uid), sessionid);
-	if (lsmblob_is_set(blob)) {
-		if (security_secid_to_secctx(blob, &lsmctx, LSMBLOB_FIRST)) {
-			audit_log_format(ab, " obj=(none)");
-			rc = 1;
-		} else {
-			audit_log_format(ab, " obj=%s", lsmctx.context);
-			security_release_secctx(&lsmctx);
-		}
-	}
+	if (lsmblob_is_set(blob))
+		rc = audit_log_object_context(ab, blob);
 	audit_log_format(ab, " ocomm=");
 	audit_log_untrustedstring(ab, comm);
 	audit_log_end(ab);
@@ -1277,26 +1259,15 @@ static void show_special(struct audit_context *context, int *call_panic)
 				context->socketcall.args[i]);
 		break; }
 	case AUDIT_IPC: {
-		u32 osid = context->ipc.osid;
+		struct lsmblob *oblob = &context->ipc.oblob;
 
 		audit_log_format(ab, "ouid=%u ogid=%u mode=%#ho",
 				 from_kuid(&init_user_ns, context->ipc.uid),
 				 from_kgid(&init_user_ns, context->ipc.gid),
 				 context->ipc.mode);
-		if (osid) {
-			struct lsmcontext lsmcxt;
-			struct lsmblob blob;
-
-			lsmblob_init(&blob, osid);
-			if (security_secid_to_secctx(&blob, &lsmcxt,
-						     LSMBLOB_FIRST)) {
-				audit_log_format(ab, " osid=%u", osid);
-				*call_panic = 1;
-			} else {
-				audit_log_format(ab, " obj=%s", lsmcxt.context);
-				security_release_secctx(&lsmcxt);
-			}
-		}
+		if (lsmblob_is_set(oblob) &&
+		    audit_log_object_context(ab, oblob))
+			*call_panic = 1;
 		if (context->ipc.has_perm) {
 			audit_log_end(ab);
 			ab = audit_log_start(context, GFP_KERNEL,
@@ -1441,20 +1412,9 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
 				 from_kgid(&init_user_ns, n->gid),
 				 MAJOR(n->rdev),
 				 MINOR(n->rdev));
-	if (n->osid != 0) {
-		struct lsmblob blob;
-		struct lsmcontext lsmctx;
-
-		lsmblob_init(&blob, n->osid);
-		if (security_secid_to_secctx(&blob, &lsmctx, LSMBLOB_FIRST)) {
-			audit_log_format(ab, " osid=%u", n->osid);
-			if (call_panic)
-				*call_panic = 2;
-		} else {
-			audit_log_format(ab, " obj=%s", lsmctx.context);
-			security_release_secctx(&lsmctx);
-		}
-	}
+	if (lsmblob_is_set(&n->oblob) &&
+	    audit_log_object_context(ab, &n->oblob) && call_panic)
+		*call_panic = 2;
 
 	/* log the audit_names record type */
 	switch (n->type) {
@@ -2001,17 +1961,13 @@ static void audit_copy_inode(struct audit_names *name,
 			     const struct dentry *dentry,
 			     struct inode *inode, unsigned int flags)
 {
-	struct lsmblob blob;
-
 	name->ino   = inode->i_ino;
 	name->dev   = inode->i_sb->s_dev;
 	name->mode  = inode->i_mode;
 	name->uid   = inode->i_uid;
 	name->gid   = inode->i_gid;
 	name->rdev  = inode->i_rdev;
-	security_inode_getsecid(inode, &blob);
-	/* scaffolding until osid is updated */
-	name->osid = blob.secid[0];
+	security_inode_getsecid(inode, &name->oblob);
 	if (flags & AUDIT_INODE_NOEVAL) {
 		name->fcap_ver = -1;
 		return;
@@ -2358,17 +2314,12 @@ void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
 void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
 {
 	struct audit_context *context = audit_context();
-	struct lsmblob blob;
 
 	context->ipc.uid = ipcp->uid;
 	context->ipc.gid = ipcp->gid;
 	context->ipc.mode = ipcp->mode;
 	context->ipc.has_perm = 0;
-	security_ipc_getsecid(ipcp, &blob);
-	/* context->ipc.osid will be changed to a lsmblob later in
-	 * the patch series. This will allow auditing of all the object
-	 * labels associated with the ipc object. */
-	context->ipc.osid = lsmblob_value(&blob);
+	security_ipc_getsecid(ipcp, &context->ipc.oblob);
 	context->type = AUDIT_IPC;
 }
 
-- 
2.31.1


^ permalink raw reply related

* [PATCH v28 22/25] Audit: Add record for multiple process LSM attributes
From: Casey Schaufler @ 2021-07-22  0:47 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel, paul,
	sds, linux-kernel, netdev
In-Reply-To: <20210722004758.12371-1-casey@schaufler-ca.com>

Create a new audit record type to contain the subject information
when there are multiple security modules that require such data.
This record is linked with the same timestamp and serial number
using the audit_alloc_local() mechanism.
The record is produced only in cases where there is more than one
security module with a process "context".
In cases where this record is produced the subj= fields of
other records in the audit event will be set to "subj=?".

An example of the MAC_TASK_CONTEXTS (1420) record is:

        type=UNKNOWN[1420]
        msg=audit(1600880931.832:113)
        subj_apparmor="=unconfined"
        subj_smack="_"

There will be a subj_$LSM= entry for each security module
LSM that supports the secid_to_secctx and secctx_to_secid
hooks. The BPF security module implements secid/secctx
translation hooks, so it has to be considered to provide a
secctx even though it may not actually do so.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
To: paul@paul-moore.com
To: linux-audit@redhat.com
To: rgb@redhat.com
Cc: netdev@vger.kernel.org
---
 drivers/android/binder.c                |  2 +-
 include/linux/audit.h                   | 16 +++++
 include/linux/security.h                | 16 ++++-
 include/net/netlabel.h                  |  2 +-
 include/net/scm.h                       |  2 +-
 include/net/xfrm.h                      | 13 +++-
 include/uapi/linux/audit.h              |  1 +
 kernel/audit.c                          | 90 +++++++++++++++++++------
 kernel/auditfilter.c                    |  5 +-
 kernel/auditsc.c                        | 27 ++++++--
 net/ipv4/ip_sockglue.c                  |  2 +-
 net/netfilter/nf_conntrack_netlink.c    |  4 +-
 net/netfilter/nf_conntrack_standalone.c |  2 +-
 net/netfilter/nfnetlink_queue.c         |  2 +-
 net/netlabel/netlabel_unlabeled.c       | 21 +++---
 net/netlabel/netlabel_user.c            | 14 ++--
 net/netlabel/netlabel_user.h            |  6 +-
 net/xfrm/xfrm_policy.c                  |  8 ++-
 net/xfrm/xfrm_state.c                   | 18 +++--
 security/integrity/ima/ima_api.c        |  6 +-
 security/integrity/integrity_audit.c    |  5 +-
 security/security.c                     | 46 ++++++++-----
 security/smack/smackfs.c                |  3 +-
 23 files changed, 221 insertions(+), 90 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 2c3a2348a144..3520caa0260c 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2722,7 +2722,7 @@ static void binder_transaction(struct binder_proc *proc,
 		 * case well anyway.
 		 */
 		security_task_getsecid_obj(proc->tsk, &blob);
-		ret = security_secid_to_secctx(&blob, &lsmctx);
+		ret = security_secid_to_secctx(&blob, &lsmctx, LSMBLOB_DISPLAY);
 		if (ret) {
 			return_error = BR_FAILED_REPLY;
 			return_error_param = ret;
diff --git a/include/linux/audit.h b/include/linux/audit.h
index 97cd7471e572..85eb87f6f92d 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -291,6 +291,7 @@ extern int  audit_alloc(struct task_struct *task);
 extern void __audit_free(struct task_struct *task);
 extern struct audit_context *audit_alloc_local(gfp_t gfpflags);
 extern void audit_free_context(struct audit_context *context);
+extern void audit_free_local(struct audit_context *context);
 extern void __audit_syscall_entry(int major, unsigned long a0, unsigned long a1,
 				  unsigned long a2, unsigned long a3);
 extern void __audit_syscall_exit(int ret_success, long ret_value);
@@ -386,6 +387,19 @@ static inline void audit_ptrace(struct task_struct *t)
 		__audit_ptrace(t);
 }
 
+static inline struct audit_context *audit_alloc_for_lsm(gfp_t gfp)
+{
+	struct audit_context *context = audit_context();
+
+	if (context)
+		return context;
+
+	if (lsm_multiple_contexts())
+		return audit_alloc_local(gfp);
+
+	return NULL;
+}
+
 				/* Private API (for audit.c only) */
 extern void __audit_ipc_obj(struct kern_ipc_perm *ipcp);
 extern void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mode);
@@ -560,6 +574,8 @@ extern int audit_signals;
 }
 static inline void audit_free_context(struct audit_context *context)
 { }
+static inline void audit_free_local(struct audit_context *context)
+{ }
 static inline int audit_alloc(struct task_struct *task)
 {
 	return 0;
diff --git a/include/linux/security.h b/include/linux/security.h
index 3e9743118fb9..b3cf68cf2bd6 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -182,6 +182,8 @@ struct lsmblob {
 #define LSMBLOB_INVALID		-1	/* Not a valid LSM slot number */
 #define LSMBLOB_NEEDED		-2	/* Slot requested on initialization */
 #define LSMBLOB_NOT_NEEDED	-3	/* Slot not requested */
+#define LSMBLOB_DISPLAY		-4	/* Use the "display" slot */
+#define LSMBLOB_FIRST		-5	/* Use the default "display" slot */
 
 /**
  * lsmblob_init - initialize an lsmblob structure
@@ -248,6 +250,15 @@ static inline u32 lsmblob_value(const struct lsmblob *blob)
 	return 0;
 }
 
+static inline bool lsm_multiple_contexts(void)
+{
+#ifdef CONFIG_SECURITY
+	return lsm_slot_to_name(1) != NULL;
+#else
+	return false;
+#endif
+}
+
 /* These functions are in security/commoncap.c */
 extern int cap_capable(const struct cred *cred, struct user_namespace *ns,
 		       int cap, unsigned int opts);
@@ -578,7 +589,8 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
 			 size_t size);
 int security_netlink_send(struct sock *sk, struct sk_buff *skb);
 int security_ismaclabel(const char *name);
-int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp);
+int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp,
+			     int display);
 int security_secctx_to_secid(const char *secdata, u32 seclen,
 			     struct lsmblob *blob);
 void security_release_secctx(struct lsmcontext *cp);
@@ -1433,7 +1445,7 @@ static inline int security_ismaclabel(const char *name)
 }
 
 static inline int security_secid_to_secctx(struct lsmblob *blob,
-					   struct lsmcontext *cp)
+					   struct lsmcontext *cp, int display)
 {
 	return -EOPNOTSUPP;
 }
diff --git a/include/net/netlabel.h b/include/net/netlabel.h
index 73fc25b4042b..216cb1ffc8f0 100644
--- a/include/net/netlabel.h
+++ b/include/net/netlabel.h
@@ -97,7 +97,7 @@ struct calipso_doi;
 
 /* NetLabel audit information */
 struct netlbl_audit {
-	u32 secid;
+	struct lsmblob lsmdata;
 	kuid_t loginuid;
 	unsigned int sessionid;
 };
diff --git a/include/net/scm.h b/include/net/scm.h
index b77a52f93389..f4d567d4885e 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -101,7 +101,7 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
 		 * and the infrastructure will know which it is.
 		 */
 		lsmblob_init(&lb, scm->secid);
-		err = security_secid_to_secctx(&lb, &context);
+		err = security_secid_to_secctx(&lb, &context, LSMBLOB_DISPLAY);
 
 		if (!err) {
 			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, context.len,
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index cbff7c2a9724..a10fa01f7bf4 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -660,13 +660,22 @@ struct xfrm_spi_skb_cb {
 #define XFRM_SPI_SKB_CB(__skb) ((struct xfrm_spi_skb_cb *)&((__skb)->cb[0]))
 
 #ifdef CONFIG_AUDITSYSCALL
-static inline struct audit_buffer *xfrm_audit_start(const char *op)
+static inline struct audit_buffer *xfrm_audit_start(const char *op,
+						    struct audit_context **lac)
 {
+	struct audit_context *context;
 	struct audit_buffer *audit_buf = NULL;
 
 	if (audit_enabled == AUDIT_OFF)
 		return NULL;
-	audit_buf = audit_log_start(audit_context(), GFP_ATOMIC,
+	context = audit_context();
+	if (lac != NULL) {
+		if (lsm_multiple_contexts() && context == NULL)
+			context = audit_alloc_local(GFP_ATOMIC);
+		*lac = context;
+	}
+
+	audit_buf = audit_log_start(context, GFP_ATOMIC,
 				    AUDIT_MAC_IPSEC_EVENT);
 	if (audit_buf == NULL)
 		return NULL;
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index daa481729e9b..4432a8bed8e0 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -139,6 +139,7 @@
 #define AUDIT_MAC_UNLBL_STCDEL	1417	/* NetLabel: del a static label */
 #define AUDIT_MAC_CALIPSO_ADD	1418	/* NetLabel: add CALIPSO DOI entry */
 #define AUDIT_MAC_CALIPSO_DEL	1419	/* NetLabel: del CALIPSO DOI entry */
+#define AUDIT_MAC_TASK_CONTEXTS	1420	/* Multiple LSM contexts */
 
 #define AUDIT_FIRST_KERN_ANOM_MSG   1700
 #define AUDIT_LAST_KERN_ANOM_MSG    1799
diff --git a/kernel/audit.c b/kernel/audit.c
index 841123390d41..cba63789a164 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -386,10 +386,12 @@ void audit_log_lost(const char *message)
 static int audit_log_config_change(char *function_name, u32 new, u32 old,
 				   int allow_changes)
 {
+	struct audit_context *context;
 	struct audit_buffer *ab;
 	int rc = 0;
 
-	ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
+	context = audit_alloc_for_lsm(GFP_KERNEL);
+	ab = audit_log_start(context, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
 	if (unlikely(!ab))
 		return rc;
 	audit_log_format(ab, "op=set %s=%u old=%u ", function_name, new, old);
@@ -399,6 +401,7 @@ static int audit_log_config_change(char *function_name, u32 new, u32 old,
 		allow_changes = 0; /* Something weird, deny request */
 	audit_log_format(ab, " res=%d", allow_changes);
 	audit_log_end(ab);
+	audit_free_local(context);
 	return rc;
 }
 
@@ -1072,12 +1075,6 @@ static void audit_log_common_recv_msg(struct audit_context *context,
 	audit_log_task_context(*ab);
 }
 
-static inline void audit_log_user_recv_msg(struct audit_buffer **ab,
-					   u16 msg_type)
-{
-	audit_log_common_recv_msg(NULL, ab, msg_type);
-}
-
 int is_audit_feature_set(int i)
 {
 	return af.features & AUDIT_FEATURE_TO_MASK(i);
@@ -1190,6 +1187,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 	struct audit_buffer	*ab;
 	u16			msg_type = nlh->nlmsg_type;
 	struct audit_sig_info   *sig_data;
+	struct audit_context	*lcontext;
 
 	err = audit_netlink_ok(skb, msg_type);
 	if (err)
@@ -1357,7 +1355,8 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 				if (err)
 					break;
 			}
-			audit_log_user_recv_msg(&ab, msg_type);
+			lcontext = audit_alloc_for_lsm(GFP_KERNEL);
+			audit_log_common_recv_msg(lcontext, &ab, msg_type);
 			if (msg_type != AUDIT_USER_TTY) {
 				/* ensure NULL termination */
 				str[data_len - 1] = '\0';
@@ -1371,6 +1370,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 				audit_log_n_untrustedstring(ab, str, data_len);
 			}
 			audit_log_end(ab);
+			audit_free_local(lcontext);
 		}
 		break;
 	case AUDIT_ADD_RULE:
@@ -1378,13 +1378,15 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		if (data_len < sizeof(struct audit_rule_data))
 			return -EINVAL;
 		if (audit_enabled == AUDIT_LOCKED) {
-			audit_log_common_recv_msg(audit_context(), &ab,
+			lcontext = audit_alloc_for_lsm(GFP_KERNEL);
+			audit_log_common_recv_msg(lcontext, &ab,
 						  AUDIT_CONFIG_CHANGE);
 			audit_log_format(ab, " op=%s audit_enabled=%d res=0",
 					 msg_type == AUDIT_ADD_RULE ?
 						"add_rule" : "remove_rule",
 					 audit_enabled);
 			audit_log_end(ab);
+			audit_free_local(lcontext);
 			return -EPERM;
 		}
 		err = audit_rule_change(msg_type, seq, data, data_len);
@@ -1394,10 +1396,11 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		break;
 	case AUDIT_TRIM:
 		audit_trim_trees();
-		audit_log_common_recv_msg(audit_context(), &ab,
-					  AUDIT_CONFIG_CHANGE);
+		lcontext = audit_alloc_for_lsm(GFP_KERNEL);
+		audit_log_common_recv_msg(lcontext, &ab, AUDIT_CONFIG_CHANGE);
 		audit_log_format(ab, " op=trim res=1");
 		audit_log_end(ab);
+		audit_free_local(lcontext);
 		break;
 	case AUDIT_MAKE_EQUIV: {
 		void *bufp = data;
@@ -1425,14 +1428,15 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		/* OK, here comes... */
 		err = audit_tag_tree(old, new);
 
-		audit_log_common_recv_msg(audit_context(), &ab,
-					  AUDIT_CONFIG_CHANGE);
+		lcontext = audit_alloc_for_lsm(GFP_KERNEL);
+		audit_log_common_recv_msg(lcontext, &ab, AUDIT_CONFIG_CHANGE);
 		audit_log_format(ab, " op=make_equiv old=");
 		audit_log_untrustedstring(ab, old);
 		audit_log_format(ab, " new=");
 		audit_log_untrustedstring(ab, new);
 		audit_log_format(ab, " res=%d", !err);
 		audit_log_end(ab);
+		audit_free_local(lcontext);
 		kfree(old);
 		kfree(new);
 		break;
@@ -1443,7 +1447,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 
 		if (lsmblob_is_set(&audit_sig_lsm)) {
 			err = security_secid_to_secctx(&audit_sig_lsm,
-						       &context);
+						       &context, LSMBLOB_FIRST);
 			if (err)
 				return err;
 		}
@@ -1498,13 +1502,14 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		old.enabled = t & AUDIT_TTY_ENABLE;
 		old.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
 
-		audit_log_common_recv_msg(audit_context(), &ab,
-					  AUDIT_CONFIG_CHANGE);
+		lcontext = audit_alloc_for_lsm(GFP_KERNEL);
+		audit_log_common_recv_msg(lcontext, &ab, AUDIT_CONFIG_CHANGE);
 		audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d"
 				 " old-log_passwd=%d new-log_passwd=%d res=%d",
 				 old.enabled, s.enabled, old.log_passwd,
 				 s.log_passwd, !err);
 		audit_log_end(ab);
+		audit_free_local(lcontext);
 		break;
 	}
 	default:
@@ -1550,6 +1555,7 @@ static void audit_receive(struct sk_buff  *skb)
 /* Log information about who is connecting to the audit multicast socket */
 static void audit_log_multicast(int group, const char *op, int err)
 {
+	struct audit_context *context;
 	const struct cred *cred;
 	struct tty_struct *tty;
 	char comm[sizeof(current->comm)];
@@ -1558,7 +1564,8 @@ static void audit_log_multicast(int group, const char *op, int err)
 	if (!audit_enabled)
 		return;
 
-	ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_EVENT_LISTENER);
+	context = audit_alloc_for_lsm(GFP_KERNEL);
+	ab = audit_log_start(context, GFP_KERNEL, AUDIT_EVENT_LISTENER);
 	if (!ab)
 		return;
 
@@ -1577,6 +1584,7 @@ static void audit_log_multicast(int group, const char *op, int err)
 	audit_log_d_path_exe(ab, current->mm); /* exe= */
 	audit_log_format(ab, " nl-mcgrp=%d op=%s res=%d", group, op, !err);
 	audit_log_end(ab);
+	audit_free_local(context);
 }
 
 /* Run custom bind function on netlink socket group connect or bind requests. */
@@ -2128,6 +2136,36 @@ void audit_log_key(struct audit_buffer *ab, char *key)
 		audit_log_format(ab, "(null)");
 }
 
+static void audit_log_lsm(struct audit_context *context, struct lsmblob *blob)
+{
+	struct audit_buffer *ab;
+	struct lsmcontext lsmdata;
+	bool sep = false;
+	int error;
+	int i;
+
+	ab = audit_log_start(context, GFP_ATOMIC, AUDIT_MAC_TASK_CONTEXTS);
+	if (!ab)
+		return; /* audit_panic or being filtered */
+
+	for (i = 0; i < LSMBLOB_ENTRIES; i++) {
+		if (blob->secid[i] == 0)
+			continue;
+		error = security_secid_to_secctx(blob, &lsmdata, i);
+		if (error && error != -EINVAL) {
+			audit_panic("error in audit_log_lsm");
+			return;
+		}
+
+		audit_log_format(ab, "%ssubj_%s=\"%s\"", sep ? " " : "",
+				 lsm_slot_to_name(i), lsmdata.context);
+		sep = true;
+
+		security_release_secctx(&lsmdata);
+	}
+	audit_log_end(ab);
+}
+
 int audit_log_task_context(struct audit_buffer *ab)
 {
 	int error;
@@ -2138,7 +2176,18 @@ int audit_log_task_context(struct audit_buffer *ab)
 	if (!lsmblob_is_set(&blob))
 		return 0;
 
-	error = security_secid_to_secctx(&blob, &context);
+	/*
+	 * If there is more than one security module that has a
+	 * subject "context" it's necessary to put the subject data
+	 * into a separate record to maintain compatibility.
+	 */
+	if (lsm_multiple_contexts()) {
+		audit_log_format(ab, " subj=?");
+		audit_log_lsm(ab->ctx, &blob);
+		return 0;
+	}
+
+	error = security_secid_to_secctx(&blob, &context, LSMBLOB_FIRST);
 	if (error) {
 		if (error != -EINVAL)
 			goto error_path;
@@ -2274,6 +2323,7 @@ static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
 				   unsigned int oldsessionid,
 				   unsigned int sessionid, int rc)
 {
+	struct audit_context *context;
 	struct audit_buffer *ab;
 	uid_t uid, oldloginuid, loginuid;
 	struct tty_struct *tty;
@@ -2281,7 +2331,8 @@ static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
 	if (!audit_enabled)
 		return;
 
-	ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_LOGIN);
+	context = audit_alloc_for_lsm(GFP_KERNEL);
+	ab = audit_log_start(context, GFP_KERNEL, AUDIT_LOGIN);
 	if (!ab)
 		return;
 
@@ -2297,6 +2348,7 @@ static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
 			 oldsessionid, sessionid, !rc);
 	audit_put_tty(tty);
 	audit_log_end(ab);
+	audit_free_local(context);
 }
 
 /**
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 1ba14a7a38f7..fd71c6bac200 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1098,12 +1098,14 @@ static void audit_list_rules(int seq, struct sk_buff_head *q)
 /* Log rule additions and removals */
 static void audit_log_rule_change(char *action, struct audit_krule *rule, int res)
 {
+	struct audit_context *context;
 	struct audit_buffer *ab;
 
 	if (!audit_enabled)
 		return;
 
-	ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
+	context = audit_alloc_for_lsm(GFP_KERNEL);
+	ab = audit_log_start(context, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
 	if (!ab)
 		return;
 	audit_log_session_info(ab);
@@ -1112,6 +1114,7 @@ static void audit_log_rule_change(char *action, struct audit_krule *rule, int re
 	audit_log_key(ab, rule->filterkey);
 	audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
 	audit_log_end(ab);
+	audit_free_local(context);
 }
 
 /**
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 0e58a3ab56f5..01fdcbf468c0 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -993,12 +993,11 @@ struct audit_context *audit_alloc_local(gfp_t gfpflags)
 	context = audit_alloc_context(AUDIT_STATE_BUILD, gfpflags);
 	if (!context) {
 		audit_log_lost("out of memory in audit_alloc_local");
-		goto out;
+		return NULL;
 	}
 	context->serial = audit_serial();
 	ktime_get_coarse_real_ts64(&context->ctime);
 	context->local = true;
-out:
 	return context;
 }
 EXPORT_SYMBOL(audit_alloc_local);
@@ -1019,6 +1018,13 @@ void audit_free_context(struct audit_context *context)
 }
 EXPORT_SYMBOL(audit_free_context);
 
+void audit_free_local(struct audit_context *context)
+{
+	if (context && context->local)
+		audit_free_context(context);
+}
+EXPORT_SYMBOL(audit_free_local);
+
 static int audit_log_pid_context(struct audit_context *context, pid_t pid,
 				 kuid_t auid, kuid_t uid,
 				 unsigned int sessionid,
@@ -1036,7 +1042,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
 			 from_kuid(&init_user_ns, auid),
 			 from_kuid(&init_user_ns, uid), sessionid);
 	if (lsmblob_is_set(blob)) {
-		if (security_secid_to_secctx(blob, &lsmctx)) {
+		if (security_secid_to_secctx(blob, &lsmctx, LSMBLOB_FIRST)) {
 			audit_log_format(ab, " obj=(none)");
 			rc = 1;
 		} else {
@@ -1282,7 +1288,8 @@ static void show_special(struct audit_context *context, int *call_panic)
 			struct lsmblob blob;
 
 			lsmblob_init(&blob, osid);
-			if (security_secid_to_secctx(&blob, &lsmcxt)) {
+			if (security_secid_to_secctx(&blob, &lsmcxt,
+						     LSMBLOB_FIRST)) {
 				audit_log_format(ab, " osid=%u", osid);
 				*call_panic = 1;
 			} else {
@@ -1439,7 +1446,7 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
 		struct lsmcontext lsmctx;
 
 		lsmblob_init(&blob, n->osid);
-		if (security_secid_to_secctx(&blob, &lsmctx)) {
+		if (security_secid_to_secctx(&blob, &lsmctx, LSMBLOB_FIRST)) {
 			audit_log_format(ab, " osid=%u", n->osid);
 			if (call_panic)
 				*call_panic = 2;
@@ -2637,10 +2644,12 @@ void __audit_ntp_log(const struct audit_ntp_data *ad)
 void __audit_log_nfcfg(const char *name, u8 af, unsigned int nentries,
 		       enum audit_nfcfgop op, gfp_t gfp)
 {
+	struct audit_context *context;
 	struct audit_buffer *ab;
 	char comm[sizeof(current->comm)];
 
-	ab = audit_log_start(audit_context(), gfp, AUDIT_NETFILTER_CFG);
+	context = audit_alloc_for_lsm(GFP_KERNEL);
+	ab = audit_log_start(context, gfp, AUDIT_NETFILTER_CFG);
 	if (!ab)
 		return;
 	audit_log_format(ab, "table=%s family=%u entries=%u op=%s",
@@ -2651,6 +2660,7 @@ void __audit_log_nfcfg(const char *name, u8 af, unsigned int nentries,
 	audit_log_format(ab, " comm=");
 	audit_log_untrustedstring(ab, get_task_comm(comm, current));
 	audit_log_end(ab);
+	audit_free_local(context);
 }
 EXPORT_SYMBOL_GPL(__audit_log_nfcfg);
 
@@ -2685,6 +2695,7 @@ static void audit_log_task(struct audit_buffer *ab)
  */
 void audit_core_dumps(long signr)
 {
+	struct audit_context *context;
 	struct audit_buffer *ab;
 
 	if (!audit_enabled)
@@ -2693,12 +2704,14 @@ void audit_core_dumps(long signr)
 	if (signr == SIGQUIT)	/* don't care for those */
 		return;
 
-	ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_ANOM_ABEND);
+	context = audit_alloc_for_lsm(GFP_KERNEL);
+	ab = audit_log_start(context, GFP_KERNEL, AUDIT_ANOM_ABEND);
 	if (unlikely(!ab))
 		return;
 	audit_log_task(ab);
 	audit_log_format(ab, " sig=%ld res=1", signr);
 	audit_log_end(ab);
+	audit_free_local(context);
 }
 
 /**
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index ae073b642fa7..5c0029a3a595 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -140,7 +140,7 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
 		return;
 
 	lsmblob_init(&lb, secid);
-	err = security_secid_to_secctx(&lb, &context);
+	err = security_secid_to_secctx(&lb, &context, LSMBLOB_DISPLAY);
 	if (err)
 		return;
 
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 668b31ecd638..05bdbb942499 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -347,7 +347,7 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
 	 * security_secid_to_secctx() will know which security module
 	 * to use to create the secctx.  */
 	lsmblob_init(&blob, ct->secmark);
-	ret = security_secid_to_secctx(&blob, &context);
+	ret = security_secid_to_secctx(&blob, &context, LSMBLOB_DISPLAY);
 	if (ret)
 		return 0;
 
@@ -658,7 +658,7 @@ static inline int ctnetlink_secctx_size(const struct nf_conn *ct)
 	struct lsmblob blob;
 	struct lsmcontext context;
 
-	ret = security_secid_to_secctx(&blob, &context);
+	ret = security_secid_to_secctx(&blob, &context, LSMBLOB_DISPLAY);
 	if (ret)
 		return 0;
 
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index b5796a8e5e90..3da3770e9739 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -177,7 +177,7 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
 	struct lsmcontext context;
 
 	lsmblob_init(&blob, ct->secmark);
-	ret = security_secid_to_secctx(&blob, &context);
+	ret = security_secid_to_secctx(&blob, &context, LSMBLOB_DISPLAY);
 	if (ret)
 		return;
 
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index cffb04baf7b8..9bef0bddf7d6 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -316,7 +316,7 @@ static void nfqnl_get_sk_secctx(struct sk_buff *skb, struct lsmcontext *context)
 		 * blob. security_secid_to_secctx() will know which security
 		 * module to use to create the secctx.  */
 		lsmblob_init(&blob, skb->secmark);
-		security_secid_to_secctx(&blob, context);
+		security_secid_to_secctx(&blob, context, LSMBLOB_DISPLAY);
 	}
 
 	read_unlock_bh(&skb->sk->sk_callback_lock);
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 289602835b75..245f63f5773a 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -437,7 +437,8 @@ int netlbl_unlhsh_add(struct net *net,
 unlhsh_add_return:
 	rcu_read_unlock();
 	if (audit_buf != NULL) {
-		if (security_secid_to_secctx(lsmblob, &context) == 0) {
+		if (security_secid_to_secctx(lsmblob, &context,
+					     LSMBLOB_FIRST) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s",
 					 context.context);
 			security_release_secctx(&context);
@@ -492,7 +493,8 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
 		if (dev != NULL)
 			dev_put(dev);
 		if (entry != NULL &&
-		    security_secid_to_secctx(&entry->lsmblob, &context) == 0) {
+		    security_secid_to_secctx(&entry->lsmblob, &context,
+					     LSMBLOB_FIRST) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s",
 					 context.context);
 			security_release_secctx(&context);
@@ -552,7 +554,8 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
 		if (dev != NULL)
 			dev_put(dev);
 		if (entry != NULL &&
-		    security_secid_to_secctx(&entry->lsmblob, &context) == 0) {
+		    security_secid_to_secctx(&entry->lsmblob, &context,
+					     LSMBLOB_FIRST) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s",
 					 context.context);
 			security_release_secctx(&context);
@@ -738,11 +741,10 @@ static void netlbl_unlabel_acceptflg_set(u8 value,
 	netlabel_unlabel_acceptflg = value;
 	audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_ALLOW,
 					      audit_info);
-	if (audit_buf != NULL) {
+	if (audit_buf != NULL)
 		audit_log_format(audit_buf,
 				 " unlbl_accept=%u old=%u", value, old_val);
-		audit_log_end(audit_buf);
-	}
+	audit_log_end(audit_buf);
 }
 
 /**
@@ -1122,7 +1124,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
 		lsmb = (struct lsmblob *)&addr6->lsmblob;
 	}
 
-	ret_val = security_secid_to_secctx(lsmb, &context);
+	ret_val = security_secid_to_secctx(lsmb, &context, LSMBLOB_FIRST);
 	if (ret_val != 0)
 		goto list_cb_failure;
 	ret_val = nla_put(cb_arg->skb,
@@ -1528,14 +1530,11 @@ int __init netlbl_unlabel_defconf(void)
 	int ret_val;
 	struct netlbl_dom_map *entry;
 	struct netlbl_audit audit_info;
-	struct lsmblob blob;
 
 	/* Only the kernel is allowed to call this function and the only time
 	 * it is called is at bootup before the audit subsystem is reporting
 	 * messages so don't worry to much about these values. */
-	security_task_getsecid_subj(current, &blob);
-	/* scaffolding until audit_info.secid is converted */
-	audit_info.secid = blob.secid[0];
+	security_task_getsecid_subj(current, &audit_info.lsmdata);
 	audit_info.loginuid = GLOBAL_ROOT_UID;
 	audit_info.sessionid = 0;
 
diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
index 951ba0639d20..9c43c3cb2088 100644
--- a/net/netlabel/netlabel_user.c
+++ b/net/netlabel/netlabel_user.c
@@ -85,7 +85,6 @@ struct audit_buffer *netlbl_audit_start_common(int type,
 {
 	struct audit_buffer *audit_buf;
 	struct lsmcontext context;
-	struct lsmblob blob;
 
 	if (audit_enabled == AUDIT_OFF)
 		return NULL;
@@ -98,11 +97,14 @@ struct audit_buffer *netlbl_audit_start_common(int type,
 			 from_kuid(&init_user_ns, audit_info->loginuid),
 			 audit_info->sessionid);
 
-	lsmblob_init(&blob, audit_info->secid);
-	if (audit_info->secid != 0 &&
-	    security_secid_to_secctx(&blob, &context) == 0) {
-		audit_log_format(audit_buf, " subj=%s", context.context);
-		security_release_secctx(&context);
+	if (lsmblob_is_set(&audit_info->lsmdata)) {
+		if (!lsm_multiple_contexts() &&
+		    security_secid_to_secctx(&audit_info->lsmdata, &context,
+					     LSMBLOB_FIRST) == 0) {
+			audit_log_format(audit_buf, " subj=%s",
+					 context.context);
+			security_release_secctx(&context);
+		}
 	}
 
 	return audit_buf;
diff --git a/net/netlabel/netlabel_user.h b/net/netlabel/netlabel_user.h
index aa31f7bf79ee..e5b15ad41df7 100644
--- a/net/netlabel/netlabel_user.h
+++ b/net/netlabel/netlabel_user.h
@@ -32,11 +32,7 @@
  */
 static inline void netlbl_netlink_auditinfo(struct netlbl_audit *audit_info)
 {
-	struct lsmblob blob;
-
-	security_task_getsecid_subj(current, &blob);
-	/* scaffolding until secid is converted */
-	audit_info->secid = blob.secid[0];
+	security_task_getsecid_subj(current, &audit_info->lsmdata);
 	audit_info->loginuid = audit_get_loginuid(current);
 	audit_info->sessionid = audit_get_sessionid(current);
 }
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 827d84255021..2152e319951d 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -4178,30 +4178,34 @@ static void xfrm_audit_common_policyinfo(struct xfrm_policy *xp,
 
 void xfrm_audit_policy_add(struct xfrm_policy *xp, int result, bool task_valid)
 {
+	struct audit_context *context;
 	struct audit_buffer *audit_buf;
 
-	audit_buf = xfrm_audit_start("SPD-add");
+	audit_buf = xfrm_audit_start("SPD-add", &context);
 	if (audit_buf == NULL)
 		return;
 	xfrm_audit_helper_usrinfo(task_valid, audit_buf);
 	audit_log_format(audit_buf, " res=%u", result);
 	xfrm_audit_common_policyinfo(xp, audit_buf);
 	audit_log_end(audit_buf);
+	audit_free_local(context);
 }
 EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);
 
 void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
 			      bool task_valid)
 {
+	struct audit_context *context;
 	struct audit_buffer *audit_buf;
 
-	audit_buf = xfrm_audit_start("SPD-delete");
+	audit_buf = xfrm_audit_start("SPD-delete", &context);
 	if (audit_buf == NULL)
 		return;
 	xfrm_audit_helper_usrinfo(task_valid, audit_buf);
 	audit_log_format(audit_buf, " res=%u", result);
 	xfrm_audit_common_policyinfo(xp, audit_buf);
 	audit_log_end(audit_buf);
+	audit_free_local(context);
 }
 EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
 #endif
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index a2f4001221d1..4d174f42eb60 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -2796,29 +2796,33 @@ static void xfrm_audit_helper_pktinfo(struct sk_buff *skb, u16 family,
 
 void xfrm_audit_state_add(struct xfrm_state *x, int result, bool task_valid)
 {
+	struct audit_context *context;
 	struct audit_buffer *audit_buf;
 
-	audit_buf = xfrm_audit_start("SAD-add");
+	audit_buf = xfrm_audit_start("SAD-add", &context);
 	if (audit_buf == NULL)
 		return;
 	xfrm_audit_helper_usrinfo(task_valid, audit_buf);
 	xfrm_audit_helper_sainfo(x, audit_buf);
 	audit_log_format(audit_buf, " res=%u", result);
 	audit_log_end(audit_buf);
+	audit_free_local(context);
 }
 EXPORT_SYMBOL_GPL(xfrm_audit_state_add);
 
 void xfrm_audit_state_delete(struct xfrm_state *x, int result, bool task_valid)
 {
+	struct audit_context *context;
 	struct audit_buffer *audit_buf;
 
-	audit_buf = xfrm_audit_start("SAD-delete");
+	audit_buf = xfrm_audit_start("SAD-delete", &context);
 	if (audit_buf == NULL)
 		return;
 	xfrm_audit_helper_usrinfo(task_valid, audit_buf);
 	xfrm_audit_helper_sainfo(x, audit_buf);
 	audit_log_format(audit_buf, " res=%u", result);
 	audit_log_end(audit_buf);
+	audit_free_local(context);
 }
 EXPORT_SYMBOL_GPL(xfrm_audit_state_delete);
 
@@ -2828,7 +2832,7 @@ void xfrm_audit_state_replay_overflow(struct xfrm_state *x,
 	struct audit_buffer *audit_buf;
 	u32 spi;
 
-	audit_buf = xfrm_audit_start("SA-replay-overflow");
+	audit_buf = xfrm_audit_start("SA-replay-overflow", NULL);
 	if (audit_buf == NULL)
 		return;
 	xfrm_audit_helper_pktinfo(skb, x->props.family, audit_buf);
@@ -2846,7 +2850,7 @@ void xfrm_audit_state_replay(struct xfrm_state *x,
 	struct audit_buffer *audit_buf;
 	u32 spi;
 
-	audit_buf = xfrm_audit_start("SA-replayed-pkt");
+	audit_buf = xfrm_audit_start("SA-replayed-pkt", NULL);
 	if (audit_buf == NULL)
 		return;
 	xfrm_audit_helper_pktinfo(skb, x->props.family, audit_buf);
@@ -2861,7 +2865,7 @@ void xfrm_audit_state_notfound_simple(struct sk_buff *skb, u16 family)
 {
 	struct audit_buffer *audit_buf;
 
-	audit_buf = xfrm_audit_start("SA-notfound");
+	audit_buf = xfrm_audit_start("SA-notfound", NULL);
 	if (audit_buf == NULL)
 		return;
 	xfrm_audit_helper_pktinfo(skb, family, audit_buf);
@@ -2875,7 +2879,7 @@ void xfrm_audit_state_notfound(struct sk_buff *skb, u16 family,
 	struct audit_buffer *audit_buf;
 	u32 spi;
 
-	audit_buf = xfrm_audit_start("SA-notfound");
+	audit_buf = xfrm_audit_start("SA-notfound", NULL);
 	if (audit_buf == NULL)
 		return;
 	xfrm_audit_helper_pktinfo(skb, family, audit_buf);
@@ -2893,7 +2897,7 @@ void xfrm_audit_state_icvfail(struct xfrm_state *x,
 	__be32 net_spi;
 	__be32 net_seq;
 
-	audit_buf = xfrm_audit_start("SA-icv-failure");
+	audit_buf = xfrm_audit_start("SA-icv-failure", NULL);
 	if (audit_buf == NULL)
 		return;
 	xfrm_audit_helper_pktinfo(skb, x->props.family, audit_buf);
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 691f68d478f1..3481990a25a6 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -342,6 +342,7 @@ void ima_store_measurement(struct integrity_iint_cache *iint,
 void ima_audit_measurement(struct integrity_iint_cache *iint,
 			   const unsigned char *filename)
 {
+	struct audit_context *context;
 	struct audit_buffer *ab;
 	char *hash;
 	const char *algo_name = hash_algo_name[iint->ima_hash->algo];
@@ -358,8 +359,8 @@ void ima_audit_measurement(struct integrity_iint_cache *iint,
 		hex_byte_pack(hash + (i * 2), iint->ima_hash->digest[i]);
 	hash[i * 2] = '\0';
 
-	ab = audit_log_start(audit_context(), GFP_KERNEL,
-			     AUDIT_INTEGRITY_RULE);
+	context = audit_alloc_for_lsm(GFP_KERNEL);
+	ab = audit_log_start(context, GFP_KERNEL, AUDIT_INTEGRITY_RULE);
 	if (!ab)
 		goto out;
 
@@ -369,6 +370,7 @@ void ima_audit_measurement(struct integrity_iint_cache *iint,
 
 	audit_log_task_info(ab);
 	audit_log_end(ab);
+	audit_free_local(context);
 
 	iint->flags |= IMA_AUDITED;
 out:
diff --git a/security/integrity/integrity_audit.c b/security/integrity/integrity_audit.c
index 29220056207f..c3b313886e15 100644
--- a/security/integrity/integrity_audit.c
+++ b/security/integrity/integrity_audit.c
@@ -38,13 +38,15 @@ void integrity_audit_message(int audit_msgno, struct inode *inode,
 			     const char *cause, int result, int audit_info,
 			     int errno)
 {
+	struct audit_context *context;
 	struct audit_buffer *ab;
 	char name[TASK_COMM_LEN];
 
 	if (!integrity_audit_info && audit_info == 1)	/* Skip info messages */
 		return;
 
-	ab = audit_log_start(audit_context(), GFP_KERNEL, audit_msgno);
+	context = audit_alloc_for_lsm(GFP_KERNEL);
+	ab = audit_log_start(context, GFP_KERNEL, audit_msgno);
 	audit_log_format(ab, "pid=%d uid=%u auid=%u ses=%u",
 			 task_pid_nr(current),
 			 from_kuid(&init_user_ns, current_uid()),
@@ -64,4 +66,5 @@ void integrity_audit_message(int audit_msgno, struct inode *inode,
 	}
 	audit_log_format(ab, " res=%d errno=%d", !result, errno);
 	audit_log_end(ab);
+	audit_free_local(context);
 }
diff --git a/security/security.c b/security/security.c
index cb359e185d1a..5d7fd982f84a 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2309,7 +2309,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
 		hlist_for_each_entry(hp, &security_hook_heads.setprocattr,
 				     list) {
 			rc = hp->hook.setprocattr(name, value, size);
-			if (rc < 0)
+			if (rc < 0 && rc != -EINVAL)
 				return rc;
 		}
 
@@ -2354,13 +2354,31 @@ int security_ismaclabel(const char *name)
 }
 EXPORT_SYMBOL(security_ismaclabel);
 
-int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp)
+int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp,
+			     int ilsm)
 {
 	struct security_hook_list *hp;
-	int ilsm = lsm_task_ilsm(current);
 
 	memset(cp, 0, sizeof(*cp));
 
+	/*
+	 * ilsm either is the slot number use for formatting
+	 * or an instruction on which relative slot to use.
+	 */
+	if (ilsm == LSMBLOB_DISPLAY)
+		ilsm = lsm_task_ilsm(current);
+	else if (ilsm == LSMBLOB_FIRST)
+		ilsm = LSMBLOB_INVALID;
+	else if (ilsm < 0) {
+		WARN_ONCE(true,
+			"LSM: %s unknown interface LSM\n", __func__);
+		ilsm = LSMBLOB_INVALID;
+	} else if (ilsm >= lsm_slot) {
+		WARN_ONCE(true,
+			"LSM: %s invalid interface LSM\n", __func__);
+		ilsm = LSMBLOB_INVALID;
+	}
+
 	hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
 		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
 			continue;
@@ -2390,7 +2408,7 @@ int security_secctx_to_secid(const char *secdata, u32 seclen,
 			return hp->hook.secctx_to_secid(secdata, seclen,
 						&blob->secid[hp->lsmid->slot]);
 	}
-	return 0;
+	return -EOPNOTSUPP;
 }
 EXPORT_SYMBOL(security_secctx_to_secid);
 
@@ -2884,23 +2902,17 @@ int security_key_getsecurity(struct key *key, char **_buffer)
 int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule)
 {
 	struct security_hook_list *hp;
-	bool one_is_good = false;
-	int rc = 0;
-	int trc;
+	int ilsm = lsm_task_ilsm(current);
 
 	hlist_for_each_entry(hp, &security_hook_heads.audit_rule_init, list) {
 		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
 			continue;
-		trc = hp->hook.audit_rule_init(field, op, rulestr,
-					       &lsmrule[hp->lsmid->slot]);
-		if (trc == 0)
-			one_is_good = true;
-		else
-			rc = trc;
+		if (ilsm != LSMBLOB_INVALID && ilsm != hp->lsmid->slot)
+			continue;
+		return hp->hook.audit_rule_init(field, op, rulestr,
+						&lsmrule[hp->lsmid->slot]);
 	}
-	if (one_is_good)
-		return 0;
-	return rc;
+	return 0;
 }
 
 int security_audit_rule_known(struct audit_krule *krule)
@@ -2932,6 +2944,8 @@ int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op,
 			continue;
 		if (lsmrule[hp->lsmid->slot] == NULL)
 			continue;
+		if (lsmrule[hp->lsmid->slot] == NULL)
+			continue;
 		rc = hp->hook.audit_rule_match(blob->secid[hp->lsmid->slot],
 					       field, op,
 					       &lsmrule[hp->lsmid->slot]);
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 9cda52f2ec31..2f0f412fc403 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -185,7 +185,8 @@ static void smk_netlabel_audit_set(struct netlbl_audit *nap)
 
 	nap->loginuid = audit_get_loginuid(current);
 	nap->sessionid = audit_get_sessionid(current);
-	nap->secid = skp->smk_secid;
+	lsmblob_init(&nap->lsmdata, 0);
+	nap->lsmdata.secid[smack_lsmid.slot] = skp->smk_secid;
 }
 
 /*
-- 
2.31.1


^ permalink raw reply related

* [PATCH v28 21/25] audit: support non-syscall auxiliary records
From: Casey Schaufler @ 2021-07-22  0:47 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel, paul,
	sds, linux-kernel, Richard Guy Briggs
In-Reply-To: <20210722004758.12371-1-casey@schaufler-ca.com>

Standalone audit records have the timestamp and serial number generated
on the fly and as such are unique, making them standalone.  This new
function audit_alloc_local() generates a local audit context that will
be used only for a standalone record and its auxiliary record(s).  The
context is discarded immediately after the local associated records are
produced.

Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: linux-audit@redhat.com
To: Richard Guy Briggs <rgb@redhat.com>
---
 include/linux/audit.h |  8 ++++++++
 kernel/audit.h        |  1 +
 kernel/auditsc.c      | 33 ++++++++++++++++++++++++++++-----
 3 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/include/linux/audit.h b/include/linux/audit.h
index 418a485af114..97cd7471e572 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -289,6 +289,8 @@ static inline int audit_signal_info(int sig, struct task_struct *t)
 				/* Public API */
 extern int  audit_alloc(struct task_struct *task);
 extern void __audit_free(struct task_struct *task);
+extern struct audit_context *audit_alloc_local(gfp_t gfpflags);
+extern void audit_free_context(struct audit_context *context);
 extern void __audit_syscall_entry(int major, unsigned long a0, unsigned long a1,
 				  unsigned long a2, unsigned long a3);
 extern void __audit_syscall_exit(int ret_success, long ret_value);
@@ -552,6 +554,12 @@ static inline void audit_log_nfcfg(const char *name, u8 af,
 extern int audit_n_rules;
 extern int audit_signals;
 #else /* CONFIG_AUDITSYSCALL */
++static inline struct audit_context *audit_alloc_local(gfp_t gfpflags)
+{
+	return NULL;
+}
+static inline void audit_free_context(struct audit_context *context)
+{ }
 static inline int audit_alloc(struct task_struct *task)
 {
 	return 0;
diff --git a/kernel/audit.h b/kernel/audit.h
index b679517a3030..ddc1a69edc79 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -99,6 +99,7 @@ struct audit_proctitle {
 struct audit_context {
 	int		    dummy;	/* must be the first element */
 	int		    in_syscall;	/* 1 if task is in a syscall */
+	bool		    local;	/* local context needed */
 	enum audit_state    state, current_state;
 	unsigned int	    serial;     /* serial number for record */
 	int		    major;      /* syscall number */
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index d198f307a4d8..0e58a3ab56f5 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -931,11 +931,13 @@ static inline void audit_free_aux(struct audit_context *context)
 	}
 }
 
-static inline struct audit_context *audit_alloc_context(enum audit_state state)
+static inline struct audit_context *audit_alloc_context(enum audit_state state,
+							gfp_t gfpflags)
 {
 	struct audit_context *context;
 
-	context = kzalloc(sizeof(*context), GFP_KERNEL);
+	/* We can be called in atomic context via audit_tg() */
+	context = kzalloc(sizeof(*context), gfpflags);
 	if (!context)
 		return NULL;
 	context->state = state;
@@ -971,7 +973,8 @@ int audit_alloc(struct task_struct *tsk)
 		return 0;
 	}
 
-	if (!(context = audit_alloc_context(state))) {
+	context = audit_alloc_context(state, GFP_KERNEL);
+	if (!context) {
 		kfree(key);
 		audit_log_lost("out of memory in audit_alloc");
 		return -ENOMEM;
@@ -983,8 +986,27 @@ int audit_alloc(struct task_struct *tsk)
 	return 0;
 }
 
-static inline void audit_free_context(struct audit_context *context)
+struct audit_context *audit_alloc_local(gfp_t gfpflags)
 {
+	struct audit_context *context = NULL;
+
+	context = audit_alloc_context(AUDIT_STATE_BUILD, gfpflags);
+	if (!context) {
+		audit_log_lost("out of memory in audit_alloc_local");
+		goto out;
+	}
+	context->serial = audit_serial();
+	ktime_get_coarse_real_ts64(&context->ctime);
+	context->local = true;
+out:
+	return context;
+}
+EXPORT_SYMBOL(audit_alloc_local);
+
+void audit_free_context(struct audit_context *context)
+{
+	if (!context)
+		return;
 	audit_free_module(context);
 	audit_free_names(context);
 	unroll_tree_refs(context, NULL, 0);
@@ -995,6 +1017,7 @@ static inline void audit_free_context(struct audit_context *context)
 	audit_proctitle_free(context);
 	kfree(context);
 }
+EXPORT_SYMBOL(audit_free_context);
 
 static int audit_log_pid_context(struct audit_context *context, pid_t pid,
 				 kuid_t auid, kuid_t uid,
@@ -2223,7 +2246,7 @@ EXPORT_SYMBOL_GPL(__audit_inode_child);
 int auditsc_get_stamp(struct audit_context *ctx,
 		       struct timespec64 *t, unsigned int *serial)
 {
-	if (!ctx->in_syscall)
+	if (!ctx->in_syscall && !ctx->local)
 		return 0;
 	if (!ctx->serial)
 		ctx->serial = audit_serial();
-- 
2.31.1


^ permalink raw reply related

* [PATCH v28 20/25] LSM: Verify LSM display sanity in binder
From: Casey Schaufler @ 2021-07-22  0:47 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel, paul,
	sds, linux-kernel
In-Reply-To: <20210722004758.12371-1-casey@schaufler-ca.com>

Verify that the tasks on the ends of a binder transaction
use the same "interface_lsm" security module. This prevents
confusion of security "contexts".

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 security/security.c | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/security/security.c b/security/security.c
index 13ded9c55344..cb359e185d1a 100644
--- a/security/security.c
+++ b/security/security.c
@@ -859,9 +859,38 @@ int security_binder_set_context_mgr(struct task_struct *mgr)
 	return call_int_hook(binder_set_context_mgr, 0, mgr);
 }
 
+/**
+ * security_binder_transaction - Binder driver transaction check
+ * @from: source of the transaction
+ * @to: destination of the transaction
+ *
+ * Verify that the tasks have the same LSM "display", then
+ * call the security module hooks.
+ *
+ * Returns -EINVAL if the displays don't match, or the
+ * result of the security module checks.
+ */
 int security_binder_transaction(struct task_struct *from,
 				struct task_struct *to)
 {
+	int from_ilsm = lsm_task_ilsm(from);
+	int to_ilsm = lsm_task_ilsm(to);
+
+	/*
+	 * If the ilsm is LSMBLOB_INVALID the first module that has
+	 * an entry is used. This will be in the 0 slot.
+	 *
+	 * This is currently only required if the server has requested
+	 * peer contexts, but it would be unwieldly to have too much of
+	 * the binder driver detail here.
+	 */
+	if (from_ilsm == LSMBLOB_INVALID)
+		from_ilsm = 0;
+	if (to_ilsm == LSMBLOB_INVALID)
+		to_ilsm = 0;
+	if (from_ilsm != to_ilsm)
+		return -EINVAL;
+
 	return call_int_hook(binder_transaction, 0, from, to);
 }
 
-- 
2.31.1


^ permalink raw reply related

* [PATCH v28 19/25] NET: Store LSM netlabel data in a lsmblob
From: Casey Schaufler @ 2021-07-22  0:47 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel, paul,
	sds, linux-kernel, netdev
In-Reply-To: <20210722004758.12371-1-casey@schaufler-ca.com>

Netlabel uses LSM interfaces requiring an lsmblob and
the internal storage is used to pass information between
these interfaces, so change the internal data from a secid
to a lsmblob. Update the netlabel interfaces and their
callers to accommodate the change. This requires that the
modules using netlabel use the lsm_id.slot to access the
correct secid when using netlabel.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: netdev@vger.kernel.org
---
 include/net/netlabel.h              |  8 +--
 net/ipv4/cipso_ipv4.c               | 26 ++++++----
 net/netlabel/netlabel_kapi.c        |  6 +--
 net/netlabel/netlabel_unlabeled.c   | 79 +++++++++--------------------
 net/netlabel/netlabel_unlabeled.h   |  2 +-
 security/selinux/hooks.c            |  2 +-
 security/selinux/include/security.h |  1 +
 security/selinux/netlabel.c         |  2 +-
 security/selinux/ss/services.c      |  4 +-
 security/smack/smack.h              |  1 +
 security/smack/smack_access.c       |  2 +-
 security/smack/smack_lsm.c          | 11 ++--
 security/smack/smackfs.c            | 10 ++--
 13 files changed, 68 insertions(+), 86 deletions(-)

diff --git a/include/net/netlabel.h b/include/net/netlabel.h
index 43ae50337685..73fc25b4042b 100644
--- a/include/net/netlabel.h
+++ b/include/net/netlabel.h
@@ -166,7 +166,7 @@ struct netlbl_lsm_catmap {
  * @attr.mls: MLS sensitivity label
  * @attr.mls.cat: MLS category bitmap
  * @attr.mls.lvl: MLS sensitivity level
- * @attr.secid: LSM specific secid token
+ * @attr.lsmblob: LSM specific data
  *
  * Description:
  * This structure is used to pass security attributes between NetLabel and the
@@ -201,7 +201,7 @@ struct netlbl_lsm_secattr {
 			struct netlbl_lsm_catmap *cat;
 			u32 lvl;
 		} mls;
-		u32 secid;
+		struct lsmblob lsmblob;
 	} attr;
 };
 
@@ -415,7 +415,7 @@ int netlbl_cfg_unlbl_static_add(struct net *net,
 				const void *addr,
 				const void *mask,
 				u16 family,
-				u32 secid,
+				struct lsmblob *lsmblob,
 				struct netlbl_audit *audit_info);
 int netlbl_cfg_unlbl_static_del(struct net *net,
 				const char *dev_name,
@@ -523,7 +523,7 @@ static inline int netlbl_cfg_unlbl_static_add(struct net *net,
 					      const void *addr,
 					      const void *mask,
 					      u16 family,
-					      u32 secid,
+					      struct lsmblob *lsmblob,
 					      struct netlbl_audit *audit_info)
 {
 	return -ENOSYS;
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index 099259fc826a..9bd72ec01785 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -106,15 +106,17 @@ int cipso_v4_rbm_strictvalid = 1;
 /* Base length of the local tag (non-standard tag).
  *  Tag definition (may change between kernel versions)
  *
- * 0          8          16         24         32
- * +----------+----------+----------+----------+
- * | 10000000 | 00000110 | 32-bit secid value  |
- * +----------+----------+----------+----------+
- * | in (host byte order)|
- * +----------+----------+
- *
+ * 0          8          16                    16 + sizeof(struct lsmblob)
+ * +----------+----------+---------------------+
+ * | 10000000 | 00000110 | LSM blob data       |
+ * +----------+----------+---------------------+
+ *
+ * All secid and flag fields are in host byte order.
+ * The lsmblob structure size varies depending on which
+ * Linux security modules are built in the kernel.
+ * The data is opaque.
  */
-#define CIPSO_V4_TAG_LOC_BLEN         6
+#define CIPSO_V4_TAG_LOC_BLEN         (2 + sizeof(struct lsmblob))
 
 /*
  * Helper Functions
@@ -1460,7 +1462,11 @@ static int cipso_v4_gentag_loc(const struct cipso_v4_doi *doi_def,
 
 	buffer[0] = CIPSO_V4_TAG_LOCAL;
 	buffer[1] = CIPSO_V4_TAG_LOC_BLEN;
-	*(u32 *)&buffer[2] = secattr->attr.secid;
+	/* Ensure that there is sufficient space in the CIPSO header
+	 * for the LSM data. */
+	BUILD_BUG_ON(CIPSO_V4_TAG_LOC_BLEN > CIPSO_V4_OPT_LEN_MAX);
+	memcpy(&buffer[2], &secattr->attr.lsmblob,
+	       sizeof(secattr->attr.lsmblob));
 
 	return CIPSO_V4_TAG_LOC_BLEN;
 }
@@ -1480,7 +1486,7 @@ static int cipso_v4_parsetag_loc(const struct cipso_v4_doi *doi_def,
 				 const unsigned char *tag,
 				 struct netlbl_lsm_secattr *secattr)
 {
-	secattr->attr.secid = *(u32 *)&tag[2];
+	memcpy(&secattr->attr.lsmblob, &tag[2], sizeof(secattr->attr.lsmblob));
 	secattr->flags |= NETLBL_SECATTR_SECID;
 
 	return 0;
diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c
index beb0e573266d..158bab993e32 100644
--- a/net/netlabel/netlabel_kapi.c
+++ b/net/netlabel/netlabel_kapi.c
@@ -196,7 +196,7 @@ int netlbl_cfg_unlbl_map_add(const char *domain,
  * @addr: IP address in network byte order (struct in[6]_addr)
  * @mask: address mask in network byte order (struct in[6]_addr)
  * @family: address family
- * @secid: LSM secid value for the entry
+ * @lsmblob: LSM data value for the entry
  * @audit_info: NetLabel audit information
  *
  * Description:
@@ -210,7 +210,7 @@ int netlbl_cfg_unlbl_static_add(struct net *net,
 				const void *addr,
 				const void *mask,
 				u16 family,
-				u32 secid,
+				struct lsmblob *lsmblob,
 				struct netlbl_audit *audit_info)
 {
 	u32 addr_len;
@@ -230,7 +230,7 @@ int netlbl_cfg_unlbl_static_add(struct net *net,
 
 	return netlbl_unlhsh_add(net,
 				 dev_name, addr, mask, addr_len,
-				 secid, audit_info);
+				 lsmblob, audit_info);
 }
 
 /**
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 9910d3e9d287..289602835b75 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -66,7 +66,7 @@ struct netlbl_unlhsh_tbl {
 #define netlbl_unlhsh_addr4_entry(iter) \
 	container_of(iter, struct netlbl_unlhsh_addr4, list)
 struct netlbl_unlhsh_addr4 {
-	u32 secid;
+	struct lsmblob lsmblob;
 
 	struct netlbl_af4list list;
 	struct rcu_head rcu;
@@ -74,7 +74,7 @@ struct netlbl_unlhsh_addr4 {
 #define netlbl_unlhsh_addr6_entry(iter) \
 	container_of(iter, struct netlbl_unlhsh_addr6, list)
 struct netlbl_unlhsh_addr6 {
-	u32 secid;
+	struct lsmblob lsmblob;
 
 	struct netlbl_af6list list;
 	struct rcu_head rcu;
@@ -220,7 +220,7 @@ static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex)
  * @iface: the associated interface entry
  * @addr: IPv4 address in network byte order
  * @mask: IPv4 address mask in network byte order
- * @secid: LSM secid value for entry
+ * @lsmblob: LSM data value for entry
  *
  * Description:
  * Add a new address entry into the unlabeled connection hash table using the
@@ -231,7 +231,7 @@ static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex)
 static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
 				   const struct in_addr *addr,
 				   const struct in_addr *mask,
-				   u32 secid)
+				   struct lsmblob *lsmblob)
 {
 	int ret_val;
 	struct netlbl_unlhsh_addr4 *entry;
@@ -243,7 +243,7 @@ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
 	entry->list.addr = addr->s_addr & mask->s_addr;
 	entry->list.mask = mask->s_addr;
 	entry->list.valid = 1;
-	entry->secid = secid;
+	entry->lsmblob = *lsmblob;
 
 	spin_lock(&netlbl_unlhsh_lock);
 	ret_val = netlbl_af4list_add(&entry->list, &iface->addr4_list);
@@ -260,7 +260,7 @@ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
  * @iface: the associated interface entry
  * @addr: IPv6 address in network byte order
  * @mask: IPv6 address mask in network byte order
- * @secid: LSM secid value for entry
+ * @lsmblob: LSM data value for entry
  *
  * Description:
  * Add a new address entry into the unlabeled connection hash table using the
@@ -271,7 +271,7 @@ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
 static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface,
 				   const struct in6_addr *addr,
 				   const struct in6_addr *mask,
-				   u32 secid)
+				   struct lsmblob *lsmblob)
 {
 	int ret_val;
 	struct netlbl_unlhsh_addr6 *entry;
@@ -287,7 +287,7 @@ static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface,
 	entry->list.addr.s6_addr32[3] &= mask->s6_addr32[3];
 	entry->list.mask = *mask;
 	entry->list.valid = 1;
-	entry->secid = secid;
+	entry->lsmblob = *lsmblob;
 
 	spin_lock(&netlbl_unlhsh_lock);
 	ret_val = netlbl_af6list_add(&entry->list, &iface->addr6_list);
@@ -366,7 +366,7 @@ int netlbl_unlhsh_add(struct net *net,
 		      const void *addr,
 		      const void *mask,
 		      u32 addr_len,
-		      u32 secid,
+		      struct lsmblob *lsmblob,
 		      struct netlbl_audit *audit_info)
 {
 	int ret_val;
@@ -375,7 +375,6 @@ int netlbl_unlhsh_add(struct net *net,
 	struct netlbl_unlhsh_iface *iface;
 	struct audit_buffer *audit_buf = NULL;
 	struct lsmcontext context;
-	struct lsmblob blob;
 
 	if (addr_len != sizeof(struct in_addr) &&
 	    addr_len != sizeof(struct in6_addr))
@@ -408,7 +407,7 @@ int netlbl_unlhsh_add(struct net *net,
 		const struct in_addr *addr4 = addr;
 		const struct in_addr *mask4 = mask;
 
-		ret_val = netlbl_unlhsh_add_addr4(iface, addr4, mask4, secid);
+		ret_val = netlbl_unlhsh_add_addr4(iface, addr4, mask4, lsmblob);
 		if (audit_buf != NULL)
 			netlbl_af4list_audit_addr(audit_buf, 1,
 						  dev_name,
@@ -421,7 +420,7 @@ int netlbl_unlhsh_add(struct net *net,
 		const struct in6_addr *addr6 = addr;
 		const struct in6_addr *mask6 = mask;
 
-		ret_val = netlbl_unlhsh_add_addr6(iface, addr6, mask6, secid);
+		ret_val = netlbl_unlhsh_add_addr6(iface, addr6, mask6, lsmblob);
 		if (audit_buf != NULL)
 			netlbl_af6list_audit_addr(audit_buf, 1,
 						  dev_name,
@@ -438,11 +437,7 @@ int netlbl_unlhsh_add(struct net *net,
 unlhsh_add_return:
 	rcu_read_unlock();
 	if (audit_buf != NULL) {
-		/* lsmblob_init() puts secid into all of the secids in blob.
-		 * security_secid_to_secctx() will know which security module
-		 * to use to create the secctx.  */
-		lsmblob_init(&blob, secid);
-		if (security_secid_to_secctx(&blob, &context) == 0) {
+		if (security_secid_to_secctx(lsmblob, &context) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s",
 					 context.context);
 			security_release_secctx(&context);
@@ -477,7 +472,6 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
 	struct audit_buffer *audit_buf;
 	struct net_device *dev;
 	struct lsmcontext context;
-	struct lsmblob blob;
 
 	spin_lock(&netlbl_unlhsh_lock);
 	list_entry = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
@@ -497,13 +491,8 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
 					  addr->s_addr, mask->s_addr);
 		if (dev != NULL)
 			dev_put(dev);
-		/* lsmblob_init() puts entry->secid into all of the secids
-		 * in blob. security_secid_to_secctx() will know which
-		 * security module to use to create the secctx.  */
-		if (entry != NULL)
-			lsmblob_init(&blob, entry->secid);
 		if (entry != NULL &&
-		    security_secid_to_secctx(&blob, &context) == 0) {
+		    security_secid_to_secctx(&entry->lsmblob, &context) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s",
 					 context.context);
 			security_release_secctx(&context);
@@ -544,7 +533,6 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
 	struct audit_buffer *audit_buf;
 	struct net_device *dev;
 	struct lsmcontext context;
-	struct lsmblob blob;
 
 	spin_lock(&netlbl_unlhsh_lock);
 	list_entry = netlbl_af6list_remove(addr, mask, &iface->addr6_list);
@@ -563,13 +551,8 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
 					  addr, mask);
 		if (dev != NULL)
 			dev_put(dev);
-		/* lsmblob_init() puts entry->secid into all of the secids
-		 * in blob. security_secid_to_secctx() will know which
-		 * security module to use to create the secctx.  */
-		if (entry != NULL)
-			lsmblob_init(&blob, entry->secid);
 		if (entry != NULL &&
-		    security_secid_to_secctx(&blob, &context) == 0) {
+		    security_secid_to_secctx(&entry->lsmblob, &context) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s",
 					 context.context);
 			security_release_secctx(&context);
@@ -923,14 +906,8 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
 	if (ret_val != 0)
 		return ret_val;
 
-	/* netlbl_unlhsh_add will be changed to pass a struct lsmblob *
-	 * instead of a u32 later in this patch set. security_secctx_to_secid()
-	 * will only be setting one entry in the lsmblob struct, so it is
-	 * safe to use lsmblob_value() to get that one value. */
-
-	return netlbl_unlhsh_add(&init_net,
-				 dev_name, addr, mask, addr_len,
-				 lsmblob_value(&blob), &audit_info);
+	return netlbl_unlhsh_add(&init_net, dev_name, addr, mask, addr_len,
+				 &blob, &audit_info);
 }
 
 /**
@@ -977,11 +954,8 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
 	if (ret_val != 0)
 		return ret_val;
 
-	/* security_secctx_to_secid() will only put one secid into the lsmblob
-	 * so it's safe to use lsmblob_value() to get the secid. */
-	return netlbl_unlhsh_add(&init_net,
-				 NULL, addr, mask, addr_len,
-				 lsmblob_value(&blob), &audit_info);
+	return netlbl_unlhsh_add(&init_net, NULL, addr, mask, addr_len, &blob,
+				 &audit_info);
 }
 
 /**
@@ -1093,8 +1067,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
 	struct net_device *dev;
 	struct lsmcontext context;
 	void *data;
-	u32 secid;
-	struct lsmblob blob;
+	struct lsmblob *lsmb;
 
 	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
 			   cb_arg->seq, &netlbl_unlabel_gnl_family,
@@ -1132,7 +1105,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
 		if (ret_val != 0)
 			goto list_cb_failure;
 
-		secid = addr4->secid;
+		lsmb = (struct lsmblob *)&addr4->lsmblob;
 	} else {
 		ret_val = nla_put_in6_addr(cb_arg->skb,
 					   NLBL_UNLABEL_A_IPV6ADDR,
@@ -1146,14 +1119,10 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
 		if (ret_val != 0)
 			goto list_cb_failure;
 
-		secid = addr6->secid;
+		lsmb = (struct lsmblob *)&addr6->lsmblob;
 	}
 
-	/* lsmblob_init() secid into all of the secids in blob.
-	 * security_secid_to_secctx() will know which security module
-	 * to use to create the secctx.  */
-	lsmblob_init(&blob, secid);
-	ret_val = security_secid_to_secctx(&blob, &context);
+	ret_val = security_secid_to_secctx(lsmb, &context);
 	if (ret_val != 0)
 		goto list_cb_failure;
 	ret_val = nla_put(cb_arg->skb,
@@ -1512,7 +1481,7 @@ int netlbl_unlabel_getattr(const struct sk_buff *skb,
 					      &iface->addr4_list);
 		if (addr4 == NULL)
 			goto unlabel_getattr_nolabel;
-		secattr->attr.secid = netlbl_unlhsh_addr4_entry(addr4)->secid;
+		secattr->attr.lsmblob = netlbl_unlhsh_addr4_entry(addr4)->lsmblob;
 		break;
 	}
 #if IS_ENABLED(CONFIG_IPV6)
@@ -1525,7 +1494,7 @@ int netlbl_unlabel_getattr(const struct sk_buff *skb,
 					      &iface->addr6_list);
 		if (addr6 == NULL)
 			goto unlabel_getattr_nolabel;
-		secattr->attr.secid = netlbl_unlhsh_addr6_entry(addr6)->secid;
+		secattr->attr.lsmblob = netlbl_unlhsh_addr6_entry(addr6)->lsmblob;
 		break;
 	}
 #endif /* IPv6 */
diff --git a/net/netlabel/netlabel_unlabeled.h b/net/netlabel/netlabel_unlabeled.h
index 058e3a285d56..168920780994 100644
--- a/net/netlabel/netlabel_unlabeled.h
+++ b/net/netlabel/netlabel_unlabeled.h
@@ -211,7 +211,7 @@ int netlbl_unlhsh_add(struct net *net,
 		      const void *addr,
 		      const void *mask,
 		      u32 addr_len,
-		      u32 secid,
+		      struct lsmblob *lsmblob,
 		      struct netlbl_audit *audit_info);
 int netlbl_unlhsh_remove(struct net *net,
 			 const char *dev_name,
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 3b95eb39a3bf..12ae311b7275 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -7112,7 +7112,7 @@ static int selinux_perf_event_write(struct perf_event *event)
 }
 #endif
 
-static struct lsm_id selinux_lsmid __lsm_ro_after_init = {
+struct lsm_id selinux_lsmid __lsm_ro_after_init = {
 	.lsm  = "selinux",
 	.slot = LSMBLOB_NEEDED
 };
diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
index ac0ece01305a..9f856f2cd277 100644
--- a/security/selinux/include/security.h
+++ b/security/selinux/include/security.h
@@ -73,6 +73,7 @@
 struct netlbl_lsm_secattr;
 
 extern int selinux_enabled_boot;
+extern struct lsm_id selinux_lsmid;
 
 /*
  * type_datum properties
diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
index 6a94b31b5472..d8d7603ab14e 100644
--- a/security/selinux/netlabel.c
+++ b/security/selinux/netlabel.c
@@ -108,7 +108,7 @@ static struct netlbl_lsm_secattr *selinux_netlbl_sock_getattr(
 		return NULL;
 
 	if ((secattr->flags & NETLBL_SECATTR_SECID) &&
-	    (secattr->attr.secid == sid))
+	    (secattr->attr.lsmblob.secid[selinux_lsmid.slot] == sid))
 		return secattr;
 
 	return NULL;
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index d84c77f370dc..f6be8cd7666b 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -3899,7 +3899,7 @@ int security_netlbl_secattr_to_sid(struct selinux_state *state,
 	if (secattr->flags & NETLBL_SECATTR_CACHE)
 		*sid = *(u32 *)secattr->cache->data;
 	else if (secattr->flags & NETLBL_SECATTR_SECID)
-		*sid = secattr->attr.secid;
+		*sid = secattr->attr.lsmblob.secid[selinux_lsmid.slot];
 	else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
 		rc = -EIDRM;
 		ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
@@ -3977,7 +3977,7 @@ int security_netlbl_sid_to_secattr(struct selinux_state *state,
 	if (secattr->domain == NULL)
 		goto out;
 
-	secattr->attr.secid = sid;
+	secattr->attr.lsmblob.secid[selinux_lsmid.slot] = sid;
 	secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
 	mls_export_netlbl_lvl(policydb, ctx, secattr);
 	rc = mls_export_netlbl_cat(policydb, ctx, secattr);
diff --git a/security/smack/smack.h b/security/smack/smack.h
index b5bdf947792f..0eaae6b3f935 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -303,6 +303,7 @@ int smack_populate_secattr(struct smack_known *skp);
  * Shared data.
  */
 extern int smack_enabled;
+extern struct lsm_id smack_lsmid;
 extern int smack_cipso_direct;
 extern int smack_cipso_mapped;
 extern struct smack_known *smack_net_ambient;
diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
index 1f391f6a3d47..ceea74bbaedc 100644
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c
@@ -525,7 +525,7 @@ int smack_populate_secattr(struct smack_known *skp)
 {
 	int slen;
 
-	skp->smk_netlabel.attr.secid = skp->smk_secid;
+	skp->smk_netlabel.attr.lsmblob.secid[smack_lsmid.slot] = skp->smk_secid;
 	skp->smk_netlabel.domain = skp->smk_known;
 	skp->smk_netlabel.cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
 	if (skp->smk_netlabel.cache != NULL) {
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 7aa7ea38f627..e65497a5c095 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3720,11 +3720,12 @@ static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
 	if ((sap->flags & NETLBL_SECATTR_CACHE) != 0)
 		return (struct smack_known *)sap->cache->data;
 
+	/*
+	 * Looks like a fallback, which gives us a secid.
+	 */
 	if ((sap->flags & NETLBL_SECATTR_SECID) != 0)
-		/*
-		 * Looks like a fallback, which gives us a secid.
-		 */
-		return smack_from_secid(sap->attr.secid);
+		return smack_from_secid(
+				sap->attr.lsmblob.secid[smack_lsmid.slot]);
 
 	if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
 		/*
@@ -4701,7 +4702,7 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
 	.lbs_superblock = sizeof(struct superblock_smack),
 };
 
-static struct lsm_id smack_lsmid __lsm_ro_after_init = {
+struct lsm_id smack_lsmid __lsm_ro_after_init = {
 	.lsm  = "smack",
 	.slot = LSMBLOB_NEEDED
 };
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 3a75d2a8f517..9cda52f2ec31 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -1142,6 +1142,7 @@ static void smk_net4addr_insert(struct smk_net4addr *new)
 static ssize_t smk_write_net4addr(struct file *file, const char __user *buf,
 				size_t count, loff_t *ppos)
 {
+	struct lsmblob lsmblob;
 	struct smk_net4addr *snp;
 	struct sockaddr_in newname;
 	char *smack;
@@ -1273,10 +1274,13 @@ static ssize_t smk_write_net4addr(struct file *file, const char __user *buf,
 	 * this host so that incoming packets get labeled.
 	 * but only if we didn't get the special CIPSO option
 	 */
-	if (rc == 0 && skp != NULL)
+	if (rc == 0 && skp != NULL) {
+		lsmblob_init(&lsmblob, 0);
+		lsmblob.secid[smack_lsmid.slot] = snp->smk_label->smk_secid;
 		rc = netlbl_cfg_unlbl_static_add(&init_net, NULL,
-			&snp->smk_host, &snp->smk_mask, PF_INET,
-			snp->smk_label->smk_secid, &audit_info);
+			&snp->smk_host, &snp->smk_mask, PF_INET, &lsmblob,
+			&audit_info);
+	}
 
 	if (rc == 0)
 		rc = count;
-- 
2.31.1


^ permalink raw reply related

* [PATCH v28 18/25] LSM: security_secid_to_secctx in netlink netfilter
From: Casey Schaufler @ 2021-07-22  0:47 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel, paul,
	sds, linux-kernel, Pablo Neira Ayuso, netdev, netfilter-devel
In-Reply-To: <20210722004758.12371-1-casey@schaufler-ca.com>

Change netlink netfilter interfaces to use lsmcontext
pointers, and remove scaffolding.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: netdev@vger.kernel.org
Cc: netfilter-devel@vger.kernel.org
---
 net/netfilter/nfnetlink_queue.c | 37 +++++++++++++--------------------
 1 file changed, 14 insertions(+), 23 deletions(-)

diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index d5cff4559237..cffb04baf7b8 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -301,15 +301,13 @@ static int nfqnl_put_sk_uidgid(struct sk_buff *skb, struct sock *sk)
 	return -1;
 }
 
-static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
+static void nfqnl_get_sk_secctx(struct sk_buff *skb, struct lsmcontext *context)
 {
-	u32 seclen = 0;
 #if IS_ENABLED(CONFIG_NETWORK_SECMARK)
 	struct lsmblob blob;
-	struct lsmcontext context = { };
 
 	if (!skb || !sk_fullsock(skb->sk))
-		return 0;
+		return;
 
 	read_lock_bh(&skb->sk->sk_callback_lock);
 
@@ -318,14 +316,12 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
 		 * blob. security_secid_to_secctx() will know which security
 		 * module to use to create the secctx.  */
 		lsmblob_init(&blob, skb->secmark);
-		security_secid_to_secctx(&blob, &context);
-		*secdata = context.context;
+		security_secid_to_secctx(&blob, context);
 	}
 
 	read_unlock_bh(&skb->sk->sk_callback_lock);
-	seclen = context.len;
 #endif
-	return seclen;
+	return;
 }
 
 static u32 nfqnl_get_bridge_size(struct nf_queue_entry *entry)
@@ -397,12 +393,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
 	struct net_device *indev;
 	struct net_device *outdev;
 	struct nf_conn *ct = NULL;
+	struct lsmcontext context = { };
 	enum ip_conntrack_info ctinfo;
 	struct nfnl_ct_hook *nfnl_ct;
 	bool csum_verify;
-	struct lsmcontext scaff; /* scaffolding */
-	char *secdata = NULL;
-	u32 seclen = 0;
 
 	size = nlmsg_total_size(sizeof(struct nfgenmsg))
 		+ nla_total_size(sizeof(struct nfqnl_msg_packet_hdr))
@@ -470,9 +464,9 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
 	}
 
 	if ((queue->flags & NFQA_CFG_F_SECCTX) && entskb->sk) {
-		seclen = nfqnl_get_sk_secctx(entskb, &secdata);
-		if (seclen)
-			size += nla_total_size(seclen);
+		nfqnl_get_sk_secctx(entskb, &context);
+		if (context.len)
+			size += nla_total_size(context.len);
 	}
 
 	skb = alloc_skb(size, GFP_ATOMIC);
@@ -602,7 +596,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
 	    nfqnl_put_sk_uidgid(skb, entskb->sk) < 0)
 		goto nla_put_failure;
 
-	if (seclen && nla_put(skb, NFQA_SECCTX, seclen, secdata))
+	if (context.len &&
+	    nla_put(skb, NFQA_SECCTX, context.len, context.context))
 		goto nla_put_failure;
 
 	if (ct && nfnl_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0)
@@ -630,10 +625,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
 	}
 
 	nlh->nlmsg_len = skb->len;
-	if (seclen) {
-		lsmcontext_init(&scaff, secdata, seclen, 0);
-		security_release_secctx(&scaff);
-	}
+	if (context.len)
+		security_release_secctx(&context);
 	return skb;
 
 nla_put_failure:
@@ -641,10 +634,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
 	kfree_skb(skb);
 	net_err_ratelimited("nf_queue: error creating packet message\n");
 nlmsg_failure:
-	if (seclen) {
-		lsmcontext_init(&scaff, secdata, seclen, 0);
-		security_release_secctx(&scaff);
-	}
+	if (context.len)
+		security_release_secctx(&context);
 	return NULL;
 }
 
-- 
2.31.1


^ permalink raw reply related

* [PATCH v28 17/25] LSM: Use lsmcontext in security_inode_getsecctx
From: Casey Schaufler @ 2021-07-22  0:47 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel, paul,
	sds, linux-kernel, Chuck Lever, linux-nfs
In-Reply-To: <20210722004758.12371-1-casey@schaufler-ca.com>

Change the security_inode_getsecctx() interface to fill
a lsmcontext structure instead of data and length pointers.
This provides the information about which LSM created the
context so that security_release_secctx() can use the
correct hook.

Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: linux-nfs@vger.kernel.org
---
 fs/nfsd/nfs4xdr.c        | 23 +++++++++--------------
 include/linux/security.h |  5 +++--
 security/security.c      | 13 +++++++++++--
 3 files changed, 23 insertions(+), 18 deletions(-)

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 089ec4b61ef1..fc7ba114c298 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -2727,11 +2727,11 @@ nfsd4_encode_layout_types(struct xdr_stream *xdr, u32 layout_types)
 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
 static inline __be32
 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
-			    void *context, int len)
+			    struct lsmcontext *context)
 {
 	__be32 *p;
 
-	p = xdr_reserve_space(xdr, len + 4 + 4 + 4);
+	p = xdr_reserve_space(xdr, context->len + 4 + 4 + 4);
 	if (!p)
 		return nfserr_resource;
 
@@ -2741,13 +2741,13 @@ nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
 	 */
 	*p++ = cpu_to_be32(0); /* lfs */
 	*p++ = cpu_to_be32(0); /* pi */
-	p = xdr_encode_opaque(p, context, len);
+	p = xdr_encode_opaque(p, context->context, context->len);
 	return 0;
 }
 #else
 static inline __be32
 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
-			    void *context, int len)
+			    struct lsmcontext *context)
 { return 0; }
 #endif
 
@@ -2844,9 +2844,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
 	int err;
 	struct nfs4_acl *acl = NULL;
 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
-	struct lsmcontext scaff; /* scaffolding */
-	void *context = NULL;
-	int contextlen;
+	struct lsmcontext context = { };
 #endif
 	bool contextsupport = false;
 	struct nfsd4_compoundres *resp = rqstp->rq_resp;
@@ -2904,7 +2902,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
 	     bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) {
 		if (exp->ex_flags & NFSEXP_SECURITY_LABEL)
 			err = security_inode_getsecctx(d_inode(dentry),
-						&context, &contextlen);
+						       &context);
 		else
 			err = -EOPNOTSUPP;
 		contextsupport = (err == 0);
@@ -3324,8 +3322,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
 
 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
 	if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) {
-		status = nfsd4_encode_security_label(xdr, rqstp, context,
-								contextlen);
+		status = nfsd4_encode_security_label(xdr, rqstp, &context);
 		if (status)
 			goto out;
 	}
@@ -3346,10 +3343,8 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
 
 out:
 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
-	if (context) {
-		lsmcontext_init(&scaff, context, contextlen, 0); /*scaffolding*/
-		security_release_secctx(&scaff);
-	}
+	if (context.context)
+		security_release_secctx(&context);
 #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
 	kfree(acl);
 	if (tempfh) {
diff --git a/include/linux/security.h b/include/linux/security.h
index b19bd9e1d583..3e9743118fb9 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -585,7 +585,7 @@ void security_release_secctx(struct lsmcontext *cp);
 void security_inode_invalidate_secctx(struct inode *inode);
 int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen);
 int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen);
-int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen);
+int security_inode_getsecctx(struct inode *inode, struct lsmcontext *cp);
 int security_locked_down(enum lockdown_reason what);
 #else /* CONFIG_SECURITY */
 
@@ -1461,7 +1461,8 @@ static inline int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32
 {
 	return -EOPNOTSUPP;
 }
-static inline int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
+static inline int security_inode_getsecctx(struct inode *inode,
+					   struct lsmcontext *cp)
 {
 	return -EOPNOTSUPP;
 }
diff --git a/security/security.c b/security/security.c
index 713e0340a0d4..13ded9c55344 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2397,9 +2397,18 @@ int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
 }
 EXPORT_SYMBOL(security_inode_setsecctx);
 
-int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
+int security_inode_getsecctx(struct inode *inode, struct lsmcontext *cp)
 {
-	return call_int_hook(inode_getsecctx, -EOPNOTSUPP, inode, ctx, ctxlen);
+	struct security_hook_list *hp;
+
+	memset(cp, 0, sizeof(*cp));
+
+	hlist_for_each_entry(hp, &security_hook_heads.inode_getsecctx, list) {
+		cp->slot = hp->lsmid->slot;
+		return hp->hook.inode_getsecctx(inode, (void **)&cp->context,
+						&cp->len);
+	}
+	return -EOPNOTSUPP;
 }
 EXPORT_SYMBOL(security_inode_getsecctx);
 
-- 
2.31.1


^ permalink raw reply related

* [PATCH v28 16/25] LSM: Use lsmcontext in security_secid_to_secctx
From: Casey Schaufler @ 2021-07-22  0:47 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel, paul,
	sds, linux-kernel, netdev, netfilter-devel
In-Reply-To: <20210722004758.12371-1-casey@schaufler-ca.com>

Replace the (secctx,seclen) pointer pair with a single
lsmcontext pointer to allow return of the LSM identifier
along with the context and context length. This allows
security_release_secctx() to know how to release the
context. Callers have been modified to use or save the
returned data from the new structure.

Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: netdev@vger.kernel.org
Cc: linux-audit@redhat.com
Cc: netfilter-devel@vger.kernel.org
---
 drivers/android/binder.c                | 26 +++++++---------
 include/linux/security.h                |  4 +--
 include/net/scm.h                       |  9 ++----
 kernel/audit.c                          | 39 +++++++++++-------------
 kernel/auditsc.c                        | 31 +++++++------------
 net/ipv4/ip_sockglue.c                  |  8 ++---
 net/netfilter/nf_conntrack_netlink.c    | 18 +++++------
 net/netfilter/nf_conntrack_standalone.c |  7 ++---
 net/netfilter/nfnetlink_queue.c         |  5 +++-
 net/netlabel/netlabel_unlabeled.c       | 40 ++++++++-----------------
 net/netlabel/netlabel_user.c            |  7 ++---
 security/security.c                     | 10 +++++--
 12 files changed, 81 insertions(+), 123 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 8976ac6a5adb..2c3a2348a144 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2459,9 +2459,7 @@ static void binder_transaction(struct binder_proc *proc,
 	binder_size_t last_fixup_min_off = 0;
 	struct binder_context *context = proc->context;
 	int t_debug_id = atomic_inc_return(&binder_last_id);
-	char *secctx = NULL;
-	u32 secctx_sz = 0;
-	struct lsmcontext scaff; /* scaffolding */
+	struct lsmcontext lsmctx = { };
 
 	e = binder_transaction_log_add(&binder_transaction_log);
 	e->debug_id = t_debug_id;
@@ -2724,14 +2722,14 @@ static void binder_transaction(struct binder_proc *proc,
 		 * case well anyway.
 		 */
 		security_task_getsecid_obj(proc->tsk, &blob);
-		ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz);
+		ret = security_secid_to_secctx(&blob, &lsmctx);
 		if (ret) {
 			return_error = BR_FAILED_REPLY;
 			return_error_param = ret;
 			return_error_line = __LINE__;
 			goto err_get_secctx_failed;
 		}
-		added_size = ALIGN(secctx_sz, sizeof(u64));
+		added_size = ALIGN(lsmctx.len, sizeof(u64));
 		extra_buffers_size += added_size;
 		if (extra_buffers_size < added_size) {
 			/* integer overflow of extra_buffers_size */
@@ -2758,24 +2756,22 @@ static void binder_transaction(struct binder_proc *proc,
 		t->buffer = NULL;
 		goto err_binder_alloc_buf_failed;
 	}
-	if (secctx) {
+	if (lsmctx.context) {
 		int err;
 		size_t buf_offset = ALIGN(tr->data_size, sizeof(void *)) +
 				    ALIGN(tr->offsets_size, sizeof(void *)) +
 				    ALIGN(extra_buffers_size, sizeof(void *)) -
-				    ALIGN(secctx_sz, sizeof(u64));
+				    ALIGN(lsmctx.len, sizeof(u64));
 
 		t->security_ctx = (uintptr_t)t->buffer->user_data + buf_offset;
 		err = binder_alloc_copy_to_buffer(&target_proc->alloc,
 						  t->buffer, buf_offset,
-						  secctx, secctx_sz);
+						  lsmctx.context, lsmctx.len);
 		if (err) {
 			t->security_ctx = 0;
 			WARN_ON(1);
 		}
-		lsmcontext_init(&scaff, secctx, secctx_sz, 0);
-		security_release_secctx(&scaff);
-		secctx = NULL;
+		security_release_secctx(&lsmctx);
 	}
 	t->buffer->debug_id = t->debug_id;
 	t->buffer->transaction = t;
@@ -2832,7 +2828,7 @@ static void binder_transaction(struct binder_proc *proc,
 	off_end_offset = off_start_offset + tr->offsets_size;
 	sg_buf_offset = ALIGN(off_end_offset, sizeof(void *));
 	sg_buf_end_offset = sg_buf_offset + extra_buffers_size -
-		ALIGN(secctx_sz, sizeof(u64));
+		ALIGN(lsmctx.len, sizeof(u64));
 	off_min = 0;
 	for (buffer_offset = off_start_offset; buffer_offset < off_end_offset;
 	     buffer_offset += sizeof(binder_size_t)) {
@@ -3116,10 +3112,8 @@ static void binder_transaction(struct binder_proc *proc,
 	binder_alloc_free_buf(&target_proc->alloc, t->buffer);
 err_binder_alloc_buf_failed:
 err_bad_extra_size:
-	if (secctx) {
-		lsmcontext_init(&scaff, secctx, secctx_sz, 0);
-		security_release_secctx(&scaff);
-	}
+	if (lsmctx.context)
+		security_release_secctx(&lsmctx);
 err_get_secctx_failed:
 	kfree(tcomplete);
 	binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE);
diff --git a/include/linux/security.h b/include/linux/security.h
index 041e87f3fe4e..b19bd9e1d583 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -578,7 +578,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
 			 size_t size);
 int security_netlink_send(struct sock *sk, struct sk_buff *skb);
 int security_ismaclabel(const char *name);
-int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen);
+int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp);
 int security_secctx_to_secid(const char *secdata, u32 seclen,
 			     struct lsmblob *blob);
 void security_release_secctx(struct lsmcontext *cp);
@@ -1433,7 +1433,7 @@ static inline int security_ismaclabel(const char *name)
 }
 
 static inline int security_secid_to_secctx(struct lsmblob *blob,
-					   char **secdata, u32 *seclen)
+					   struct lsmcontext *cp)
 {
 	return -EOPNOTSUPP;
 }
diff --git a/include/net/scm.h b/include/net/scm.h
index f273c4d777ec..b77a52f93389 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -94,8 +94,6 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
 {
 	struct lsmcontext context;
 	struct lsmblob lb;
-	char *secdata;
-	u32 seclen;
 	int err;
 
 	if (test_bit(SOCK_PASSSEC, &sock->flags)) {
@@ -103,12 +101,11 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
 		 * and the infrastructure will know which it is.
 		 */
 		lsmblob_init(&lb, scm->secid);
-		err = security_secid_to_secctx(&lb, &secdata, &seclen);
+		err = security_secid_to_secctx(&lb, &context);
 
 		if (!err) {
-			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
-			/*scaffolding*/
-			lsmcontext_init(&context, secdata, seclen, 0);
+			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, context.len,
+				 context.context);
 			security_release_secctx(&context);
 		}
 	}
diff --git a/kernel/audit.c b/kernel/audit.c
index c17ec23158c4..841123390d41 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1190,9 +1190,6 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 	struct audit_buffer	*ab;
 	u16			msg_type = nlh->nlmsg_type;
 	struct audit_sig_info   *sig_data;
-	char			*ctx = NULL;
-	u32			len;
-	struct lsmcontext	scaff; /* scaffolding */
 
 	err = audit_netlink_ok(skb, msg_type);
 	if (err)
@@ -1440,33 +1437,34 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		kfree(new);
 		break;
 	}
-	case AUDIT_SIGNAL_INFO:
-		len = 0;
+	case AUDIT_SIGNAL_INFO: {
+		struct lsmcontext context = { };
+		int len = 0;
+
 		if (lsmblob_is_set(&audit_sig_lsm)) {
-			err = security_secid_to_secctx(&audit_sig_lsm, &ctx,
-						       &len);
+			err = security_secid_to_secctx(&audit_sig_lsm,
+						       &context);
 			if (err)
 				return err;
 		}
-		sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
+		sig_data = kmalloc(sizeof(*sig_data) + context.len, GFP_KERNEL);
 		if (!sig_data) {
-			if (lsmblob_is_set(&audit_sig_lsm)) {
-				lsmcontext_init(&scaff, ctx, len, 0);
-				security_release_secctx(&scaff);
-			}
+			if (lsmblob_is_set(&audit_sig_lsm))
+				security_release_secctx(&context);
 			return -ENOMEM;
 		}
 		sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
 		sig_data->pid = audit_sig_pid;
 		if (lsmblob_is_set(&audit_sig_lsm)) {
-			memcpy(sig_data->ctx, ctx, len);
-			lsmcontext_init(&scaff, ctx, len, 0);
-			security_release_secctx(&scaff);
+			len = context.len;
+			memcpy(sig_data->ctx, context.context, len);
+			security_release_secctx(&context);
 		}
 		audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
 				 sig_data, sizeof(*sig_data) + len);
 		kfree(sig_data);
 		break;
+	}
 	case AUDIT_TTY_GET: {
 		struct audit_tty_status s;
 		unsigned int t;
@@ -2132,26 +2130,23 @@ void audit_log_key(struct audit_buffer *ab, char *key)
 
 int audit_log_task_context(struct audit_buffer *ab)
 {
-	char *ctx = NULL;
-	unsigned len;
 	int error;
 	struct lsmblob blob;
-	struct lsmcontext scaff; /* scaffolding */
+	struct lsmcontext context;
 
 	security_task_getsecid_subj(current, &blob);
 	if (!lsmblob_is_set(&blob))
 		return 0;
 
-	error = security_secid_to_secctx(&blob, &ctx, &len);
+	error = security_secid_to_secctx(&blob, &context);
 	if (error) {
 		if (error != -EINVAL)
 			goto error_path;
 		return 0;
 	}
 
-	audit_log_format(ab, " subj=%s", ctx);
-	lsmcontext_init(&scaff, ctx, len, 0);
-	security_release_secctx(&scaff);
+	audit_log_format(ab, " subj=%s", context.context);
+	security_release_secctx(&context);
 	return 0;
 
 error_path:
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 1b1ddd62de6c..d198f307a4d8 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1002,9 +1002,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
 				 struct lsmblob *blob, char *comm)
 {
 	struct audit_buffer *ab;
-	struct lsmcontext lsmcxt;
-	char *ctx = NULL;
-	u32 len;
+	struct lsmcontext lsmctx;
 	int rc = 0;
 
 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
@@ -1015,13 +1013,12 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
 			 from_kuid(&init_user_ns, auid),
 			 from_kuid(&init_user_ns, uid), sessionid);
 	if (lsmblob_is_set(blob)) {
-		if (security_secid_to_secctx(blob, &ctx, &len)) {
+		if (security_secid_to_secctx(blob, &lsmctx)) {
 			audit_log_format(ab, " obj=(none)");
 			rc = 1;
 		} else {
-			audit_log_format(ab, " obj=%s", ctx);
-			lsmcontext_init(&lsmcxt, ctx, len, 0); /*scaffolding*/
-			security_release_secctx(&lsmcxt);
+			audit_log_format(ab, " obj=%s", lsmctx.context);
+			security_release_secctx(&lsmctx);
 		}
 	}
 	audit_log_format(ab, " ocomm=");
@@ -1234,7 +1231,6 @@ static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
 
 static void show_special(struct audit_context *context, int *call_panic)
 {
-	struct lsmcontext lsmcxt;
 	struct audit_buffer *ab;
 	int i;
 
@@ -1259,17 +1255,15 @@ static void show_special(struct audit_context *context, int *call_panic)
 				 from_kgid(&init_user_ns, context->ipc.gid),
 				 context->ipc.mode);
 		if (osid) {
-			char *ctx = NULL;
-			u32 len;
+			struct lsmcontext lsmcxt;
 			struct lsmblob blob;
 
 			lsmblob_init(&blob, osid);
-			if (security_secid_to_secctx(&blob, &ctx, &len)) {
+			if (security_secid_to_secctx(&blob, &lsmcxt)) {
 				audit_log_format(ab, " osid=%u", osid);
 				*call_panic = 1;
 			} else {
-				audit_log_format(ab, " obj=%s", ctx);
-				lsmcontext_init(&lsmcxt, ctx, len, 0);
+				audit_log_format(ab, " obj=%s", lsmcxt.context);
 				security_release_secctx(&lsmcxt);
 			}
 		}
@@ -1418,20 +1412,17 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
 				 MAJOR(n->rdev),
 				 MINOR(n->rdev));
 	if (n->osid != 0) {
-		char *ctx = NULL;
-		u32 len;
 		struct lsmblob blob;
-		struct lsmcontext lsmcxt;
+		struct lsmcontext lsmctx;
 
 		lsmblob_init(&blob, n->osid);
-		if (security_secid_to_secctx(&blob, &ctx, &len)) {
+		if (security_secid_to_secctx(&blob, &lsmctx)) {
 			audit_log_format(ab, " osid=%u", n->osid);
 			if (call_panic)
 				*call_panic = 2;
 		} else {
-			audit_log_format(ab, " obj=%s", ctx);
-			lsmcontext_init(&lsmcxt, ctx, len, 0); /* scaffolding */
-			security_release_secctx(&lsmcxt);
+			audit_log_format(ab, " obj=%s", lsmctx.context);
+			security_release_secctx(&lsmctx);
 		}
 	}
 
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index a7e4c1b34b6c..ae073b642fa7 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -132,8 +132,7 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
 {
 	struct lsmcontext context;
 	struct lsmblob lb;
-	char *secdata;
-	u32 seclen, secid;
+	u32 secid;
 	int err;
 
 	err = security_socket_getpeersec_dgram(NULL, skb, &secid);
@@ -141,12 +140,11 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
 		return;
 
 	lsmblob_init(&lb, secid);
-	err = security_secid_to_secctx(&lb, &secdata, &seclen);
+	err = security_secid_to_secctx(&lb, &context);
 	if (err)
 		return;
 
-	put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);
-	lsmcontext_init(&context, secdata, seclen, 0); /* scaffolding */
+	put_cmsg(msg, SOL_IP, SCM_SECURITY, context.len, context.context);
 	security_release_secctx(&context);
 }
 
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 89be957f26bd..668b31ecd638 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -339,8 +339,7 @@ static int ctnetlink_dump_mark(struct sk_buff *skb, const struct nf_conn *ct)
 static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
 {
 	struct nlattr *nest_secctx;
-	int len, ret;
-	char *secctx;
+	int ret;
 	struct lsmblob blob;
 	struct lsmcontext context;
 
@@ -348,7 +347,7 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
 	 * security_secid_to_secctx() will know which security module
 	 * to use to create the secctx.  */
 	lsmblob_init(&blob, ct->secmark);
-	ret = security_secid_to_secctx(&blob, &secctx, &len);
+	ret = security_secid_to_secctx(&blob, &context);
 	if (ret)
 		return 0;
 
@@ -357,13 +356,12 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
 	if (!nest_secctx)
 		goto nla_put_failure;
 
-	if (nla_put_string(skb, CTA_SECCTX_NAME, secctx))
+	if (nla_put_string(skb, CTA_SECCTX_NAME, context.context))
 		goto nla_put_failure;
 	nla_nest_end(skb, nest_secctx);
 
 	ret = 0;
 nla_put_failure:
-	lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
 	security_release_secctx(&context);
 	return ret;
 }
@@ -658,15 +656,15 @@ static inline int ctnetlink_secctx_size(const struct nf_conn *ct)
 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 	int len, ret;
 	struct lsmblob blob;
+	struct lsmcontext context;
 
-	/* lsmblob_init() puts ct->secmark into all of the secids in blob.
-	 * security_secid_to_secctx() will know which security module
-	 * to use to create the secctx.  */
-	lsmblob_init(&blob, ct->secmark);
-	ret = security_secid_to_secctx(&blob, NULL, &len);
+	ret = security_secid_to_secctx(&blob, &context);
 	if (ret)
 		return 0;
 
+	len = context.len;
+	security_release_secctx(&context);
+
 	return nla_total_size(0) /* CTA_SECCTX */
 	       + nla_total_size(sizeof(char) * len); /* CTA_SECCTX_NAME */
 #else
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index ca2ae290d6ee..b5796a8e5e90 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -173,19 +173,16 @@ static void ct_seq_stop(struct seq_file *s, void *v)
 static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
 {
 	int ret;
-	u32 len;
-	char *secctx;
 	struct lsmblob blob;
 	struct lsmcontext context;
 
 	lsmblob_init(&blob, ct->secmark);
-	ret = security_secid_to_secctx(&blob, &secctx, &len);
+	ret = security_secid_to_secctx(&blob, &context);
 	if (ret)
 		return;
 
-	seq_printf(s, "secctx=%s ", secctx);
+	seq_printf(s, "secctx=%s ", context.context);
 
-	lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
 	security_release_secctx(&context);
 }
 #else
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index 005900a0c397..d5cff4559237 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -306,6 +306,7 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
 	u32 seclen = 0;
 #if IS_ENABLED(CONFIG_NETWORK_SECMARK)
 	struct lsmblob blob;
+	struct lsmcontext context = { };
 
 	if (!skb || !sk_fullsock(skb->sk))
 		return 0;
@@ -317,10 +318,12 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
 		 * blob. security_secid_to_secctx() will know which security
 		 * module to use to create the secctx.  */
 		lsmblob_init(&blob, skb->secmark);
-		security_secid_to_secctx(&blob, secdata, &seclen);
+		security_secid_to_secctx(&blob, &context);
+		*secdata = context.context;
 	}
 
 	read_unlock_bh(&skb->sk->sk_callback_lock);
+	seclen = context.len;
 #endif
 	return seclen;
 }
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 61346aaa2898..9910d3e9d287 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -375,8 +375,6 @@ int netlbl_unlhsh_add(struct net *net,
 	struct netlbl_unlhsh_iface *iface;
 	struct audit_buffer *audit_buf = NULL;
 	struct lsmcontext context;
-	char *secctx = NULL;
-	u32 secctx_len;
 	struct lsmblob blob;
 
 	if (addr_len != sizeof(struct in_addr) &&
@@ -444,12 +442,9 @@ int netlbl_unlhsh_add(struct net *net,
 		 * security_secid_to_secctx() will know which security module
 		 * to use to create the secctx.  */
 		lsmblob_init(&blob, secid);
-		if (security_secid_to_secctx(&blob,
-					     &secctx,
-					     &secctx_len) == 0) {
-			audit_log_format(audit_buf, " sec_obj=%s", secctx);
-			/* scaffolding */
-			lsmcontext_init(&context, secctx, secctx_len, 0);
+		if (security_secid_to_secctx(&blob, &context) == 0) {
+			audit_log_format(audit_buf, " sec_obj=%s",
+					 context.context);
 			security_release_secctx(&context);
 		}
 		audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);
@@ -482,8 +477,6 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
 	struct audit_buffer *audit_buf;
 	struct net_device *dev;
 	struct lsmcontext context;
-	char *secctx;
-	u32 secctx_len;
 	struct lsmblob blob;
 
 	spin_lock(&netlbl_unlhsh_lock);
@@ -510,11 +503,9 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
 		if (entry != NULL)
 			lsmblob_init(&blob, entry->secid);
 		if (entry != NULL &&
-		    security_secid_to_secctx(&blob,
-					     &secctx, &secctx_len) == 0) {
-			audit_log_format(audit_buf, " sec_obj=%s", secctx);
-			/* scaffolding */
-			lsmcontext_init(&context, secctx, secctx_len, 0);
+		    security_secid_to_secctx(&blob, &context) == 0) {
+			audit_log_format(audit_buf, " sec_obj=%s",
+					 context.context);
 			security_release_secctx(&context);
 		}
 		audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
@@ -553,8 +544,6 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
 	struct audit_buffer *audit_buf;
 	struct net_device *dev;
 	struct lsmcontext context;
-	char *secctx;
-	u32 secctx_len;
 	struct lsmblob blob;
 
 	spin_lock(&netlbl_unlhsh_lock);
@@ -580,10 +569,9 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
 		if (entry != NULL)
 			lsmblob_init(&blob, entry->secid);
 		if (entry != NULL &&
-		    security_secid_to_secctx(&blob,
-					     &secctx, &secctx_len) == 0) {
-			audit_log_format(audit_buf, " sec_obj=%s", secctx);
-			lsmcontext_init(&context, secctx, secctx_len, 0);
+		    security_secid_to_secctx(&blob, &context) == 0) {
+			audit_log_format(audit_buf, " sec_obj=%s",
+					 context.context);
 			security_release_secctx(&context);
 		}
 		audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
@@ -1106,8 +1094,6 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
 	struct lsmcontext context;
 	void *data;
 	u32 secid;
-	char *secctx;
-	u32 secctx_len;
 	struct lsmblob blob;
 
 	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
@@ -1167,15 +1153,13 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
 	 * security_secid_to_secctx() will know which security module
 	 * to use to create the secctx.  */
 	lsmblob_init(&blob, secid);
-	ret_val = security_secid_to_secctx(&blob, &secctx, &secctx_len);
+	ret_val = security_secid_to_secctx(&blob, &context);
 	if (ret_val != 0)
 		goto list_cb_failure;
 	ret_val = nla_put(cb_arg->skb,
 			  NLBL_UNLABEL_A_SECCTX,
-			  secctx_len,
-			  secctx);
-	/* scaffolding */
-	lsmcontext_init(&context, secctx, secctx_len, 0);
+			  context.len,
+			  context.context);
 	security_release_secctx(&context);
 	if (ret_val != 0)
 		goto list_cb_failure;
diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
index ef139d8ae7cd..951ba0639d20 100644
--- a/net/netlabel/netlabel_user.c
+++ b/net/netlabel/netlabel_user.c
@@ -85,8 +85,6 @@ struct audit_buffer *netlbl_audit_start_common(int type,
 {
 	struct audit_buffer *audit_buf;
 	struct lsmcontext context;
-	char *secctx;
-	u32 secctx_len;
 	struct lsmblob blob;
 
 	if (audit_enabled == AUDIT_OFF)
@@ -102,9 +100,8 @@ struct audit_buffer *netlbl_audit_start_common(int type,
 
 	lsmblob_init(&blob, audit_info->secid);
 	if (audit_info->secid != 0 &&
-	    security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) {
-		audit_log_format(audit_buf, " subj=%s", secctx);
-		lsmcontext_init(&context, secctx, secctx_len, 0);/*scaffolding*/
+	    security_secid_to_secctx(&blob, &context) == 0) {
+		audit_log_format(audit_buf, " subj=%s", context.context);
 		security_release_secctx(&context);
 	}
 
diff --git a/security/security.c b/security/security.c
index 4cb540d93ab8..713e0340a0d4 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2325,18 +2325,22 @@ int security_ismaclabel(const char *name)
 }
 EXPORT_SYMBOL(security_ismaclabel);
 
-int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen)
+int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp)
 {
 	struct security_hook_list *hp;
 	int ilsm = lsm_task_ilsm(current);
 
+	memset(cp, 0, sizeof(*cp));
+
 	hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
 		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
 			continue;
-		if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot)
+		if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot) {
+			cp->slot = hp->lsmid->slot;
 			return hp->hook.secid_to_secctx(
 					blob->secid[hp->lsmid->slot],
-					secdata, seclen);
+					&cp->context, &cp->len);
+		}
 	}
 
 	return LSM_RET_DEFAULT(secid_to_secctx);
-- 
2.31.1


^ permalink raw reply related

* [PATCH v28 15/25] LSM: Ensure the correct LSM context releaser
From: Casey Schaufler @ 2021-07-22  0:47 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel, paul,
	sds, linux-kernel, Chuck Lever, linux-integrity, netdev,
	netfilter-devel, linux-nfs
In-Reply-To: <20210722004758.12371-1-casey@schaufler-ca.com>

Add a new lsmcontext data structure to hold all the information
about a "security context", including the string, its size and
which LSM allocated the string. The allocation information is
necessary because LSMs have different policies regarding the
lifecycle of these strings. SELinux allocates and destroys
them on each use, whereas Smack provides a pointer to an entry
in a list that never goes away.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: linux-integrity@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-audit@redhat.com
Cc: netfilter-devel@vger.kernel.org
To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: linux-nfs@vger.kernel.org
---
 drivers/android/binder.c                | 10 ++++---
 fs/ceph/xattr.c                         |  6 ++++-
 fs/nfs/nfs4proc.c                       |  8 ++++--
 fs/nfsd/nfs4xdr.c                       |  7 +++--
 include/linux/security.h                | 35 +++++++++++++++++++++++--
 include/net/scm.h                       |  5 +++-
 kernel/audit.c                          | 14 +++++++---
 kernel/auditsc.c                        | 12 ++++++---
 net/ipv4/ip_sockglue.c                  |  4 ++-
 net/netfilter/nf_conntrack_netlink.c    |  4 ++-
 net/netfilter/nf_conntrack_standalone.c |  4 ++-
 net/netfilter/nfnetlink_queue.c         | 13 ++++++---
 net/netlabel/netlabel_unlabeled.c       | 19 +++++++++++---
 net/netlabel/netlabel_user.c            |  4 ++-
 security/security.c                     | 11 ++++----
 15 files changed, 121 insertions(+), 35 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 96dd728809ef..8976ac6a5adb 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2461,6 +2461,7 @@ static void binder_transaction(struct binder_proc *proc,
 	int t_debug_id = atomic_inc_return(&binder_last_id);
 	char *secctx = NULL;
 	u32 secctx_sz = 0;
+	struct lsmcontext scaff; /* scaffolding */
 
 	e = binder_transaction_log_add(&binder_transaction_log);
 	e->debug_id = t_debug_id;
@@ -2772,7 +2773,8 @@ static void binder_transaction(struct binder_proc *proc,
 			t->security_ctx = 0;
 			WARN_ON(1);
 		}
-		security_release_secctx(secctx, secctx_sz);
+		lsmcontext_init(&scaff, secctx, secctx_sz, 0);
+		security_release_secctx(&scaff);
 		secctx = NULL;
 	}
 	t->buffer->debug_id = t->debug_id;
@@ -3114,8 +3116,10 @@ static void binder_transaction(struct binder_proc *proc,
 	binder_alloc_free_buf(&target_proc->alloc, t->buffer);
 err_binder_alloc_buf_failed:
 err_bad_extra_size:
-	if (secctx)
-		security_release_secctx(secctx, secctx_sz);
+	if (secctx) {
+		lsmcontext_init(&scaff, secctx, secctx_sz, 0);
+		security_release_secctx(&scaff);
+	}
 err_get_secctx_failed:
 	kfree(tcomplete);
 	binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE);
diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index 1242db8d3444..b867089e1aa4 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -1356,12 +1356,16 @@ int ceph_security_init_secctx(struct dentry *dentry, umode_t mode,
 
 void ceph_release_acl_sec_ctx(struct ceph_acl_sec_ctx *as_ctx)
 {
+#ifdef CONFIG_CEPH_FS_SECURITY_LABEL
+	struct lsmcontext scaff; /* scaffolding */
+#endif
 #ifdef CONFIG_CEPH_FS_POSIX_ACL
 	posix_acl_release(as_ctx->acl);
 	posix_acl_release(as_ctx->default_acl);
 #endif
 #ifdef CONFIG_CEPH_FS_SECURITY_LABEL
-	security_release_secctx(as_ctx->sec_ctx, as_ctx->sec_ctxlen);
+	lsmcontext_init(&scaff, as_ctx->sec_ctx, as_ctx->sec_ctxlen, 0);
+	security_release_secctx(&scaff);
 #endif
 	if (as_ctx->pagelist)
 		ceph_pagelist_release(as_ctx->pagelist);
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index e1214bb6b7ee..71004670455b 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -136,8 +136,12 @@ nfs4_label_init_security(struct inode *dir, struct dentry *dentry,
 static inline void
 nfs4_label_release_security(struct nfs4_label *label)
 {
-	if (label)
-		security_release_secctx(label->label, label->len);
+	struct lsmcontext scaff; /* scaffolding */
+
+	if (label) {
+		lsmcontext_init(&scaff, label->label, label->len, 0);
+		security_release_secctx(&scaff);
+	}
 }
 static inline u32 *nfs4_bitmask(struct nfs_server *server, struct nfs4_label *label)
 {
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 7abeccb975b2..089ec4b61ef1 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -2844,6 +2844,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
 	int err;
 	struct nfs4_acl *acl = NULL;
 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+	struct lsmcontext scaff; /* scaffolding */
 	void *context = NULL;
 	int contextlen;
 #endif
@@ -3345,8 +3346,10 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
 
 out:
 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
-	if (context)
-		security_release_secctx(context, contextlen);
+	if (context) {
+		lsmcontext_init(&scaff, context, contextlen, 0); /*scaffolding*/
+		security_release_secctx(&scaff);
+	}
 #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
 	kfree(acl);
 	if (tempfh) {
diff --git a/include/linux/security.h b/include/linux/security.h
index cdd8d9122795..041e87f3fe4e 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -133,6 +133,37 @@ enum lockdown_reason {
 
 extern const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1];
 
+/*
+ * A "security context" is the text representation of
+ * the information used by LSMs.
+ * This structure contains the string, its length, and which LSM
+ * it is useful for.
+ */
+struct lsmcontext {
+	char	*context;	/* Provided by the module */
+	u32	len;
+	int	slot;		/* Identifies the module */
+};
+
+/**
+ * lsmcontext_init - initialize an lsmcontext structure.
+ * @cp: Pointer to the context to initialize
+ * @context: Initial context, or NULL
+ * @size: Size of context, or 0
+ * @slot: Which LSM provided the context
+ *
+ * Fill in the lsmcontext from the provided information.
+ * This is a scaffolding function that will be removed when
+ * lsmcontext integration is complete.
+ */
+static inline void lsmcontext_init(struct lsmcontext *cp, char *context,
+				   u32 size, int slot)
+{
+	cp->slot = slot;
+	cp->context = context;
+	cp->len = size;
+}
+
 /*
  * Data exported by the security modules
  *
@@ -550,7 +581,7 @@ int security_ismaclabel(const char *name);
 int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen);
 int security_secctx_to_secid(const char *secdata, u32 seclen,
 			     struct lsmblob *blob);
-void security_release_secctx(char *secdata, u32 seclen);
+void security_release_secctx(struct lsmcontext *cp);
 void security_inode_invalidate_secctx(struct inode *inode);
 int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen);
 int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen);
@@ -1414,7 +1445,7 @@ static inline int security_secctx_to_secid(const char *secdata,
 	return -EOPNOTSUPP;
 }
 
-static inline void security_release_secctx(char *secdata, u32 seclen)
+static inline void security_release_secctx(struct lsmcontext *cp)
 {
 }
 
diff --git a/include/net/scm.h b/include/net/scm.h
index 23a35ff1b3f2..f273c4d777ec 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -92,6 +92,7 @@ static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
 #ifdef CONFIG_SECURITY_NETWORK
 static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
 {
+	struct lsmcontext context;
 	struct lsmblob lb;
 	char *secdata;
 	u32 seclen;
@@ -106,7 +107,9 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
 
 		if (!err) {
 			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
-			security_release_secctx(secdata, seclen);
+			/*scaffolding*/
+			lsmcontext_init(&context, secdata, seclen, 0);
+			security_release_secctx(&context);
 		}
 	}
 }
diff --git a/kernel/audit.c b/kernel/audit.c
index 8ec64e6e8bc0..c17ec23158c4 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1192,6 +1192,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 	struct audit_sig_info   *sig_data;
 	char			*ctx = NULL;
 	u32			len;
+	struct lsmcontext	scaff; /* scaffolding */
 
 	err = audit_netlink_ok(skb, msg_type);
 	if (err)
@@ -1449,15 +1450,18 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		}
 		sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
 		if (!sig_data) {
-			if (lsmblob_is_set(&audit_sig_lsm))
-				security_release_secctx(ctx, len);
+			if (lsmblob_is_set(&audit_sig_lsm)) {
+				lsmcontext_init(&scaff, ctx, len, 0);
+				security_release_secctx(&scaff);
+			}
 			return -ENOMEM;
 		}
 		sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
 		sig_data->pid = audit_sig_pid;
 		if (lsmblob_is_set(&audit_sig_lsm)) {
 			memcpy(sig_data->ctx, ctx, len);
-			security_release_secctx(ctx, len);
+			lsmcontext_init(&scaff, ctx, len, 0);
+			security_release_secctx(&scaff);
 		}
 		audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
 				 sig_data, sizeof(*sig_data) + len);
@@ -2132,6 +2136,7 @@ int audit_log_task_context(struct audit_buffer *ab)
 	unsigned len;
 	int error;
 	struct lsmblob blob;
+	struct lsmcontext scaff; /* scaffolding */
 
 	security_task_getsecid_subj(current, &blob);
 	if (!lsmblob_is_set(&blob))
@@ -2145,7 +2150,8 @@ int audit_log_task_context(struct audit_buffer *ab)
 	}
 
 	audit_log_format(ab, " subj=%s", ctx);
-	security_release_secctx(ctx, len);
+	lsmcontext_init(&scaff, ctx, len, 0);
+	security_release_secctx(&scaff);
 	return 0;
 
 error_path:
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index b5807b9b8a4d..1b1ddd62de6c 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1002,6 +1002,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
 				 struct lsmblob *blob, char *comm)
 {
 	struct audit_buffer *ab;
+	struct lsmcontext lsmcxt;
 	char *ctx = NULL;
 	u32 len;
 	int rc = 0;
@@ -1019,7 +1020,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
 			rc = 1;
 		} else {
 			audit_log_format(ab, " obj=%s", ctx);
-			security_release_secctx(ctx, len);
+			lsmcontext_init(&lsmcxt, ctx, len, 0); /*scaffolding*/
+			security_release_secctx(&lsmcxt);
 		}
 	}
 	audit_log_format(ab, " ocomm=");
@@ -1232,6 +1234,7 @@ static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
 
 static void show_special(struct audit_context *context, int *call_panic)
 {
+	struct lsmcontext lsmcxt;
 	struct audit_buffer *ab;
 	int i;
 
@@ -1266,7 +1269,8 @@ static void show_special(struct audit_context *context, int *call_panic)
 				*call_panic = 1;
 			} else {
 				audit_log_format(ab, " obj=%s", ctx);
-				security_release_secctx(ctx, len);
+				lsmcontext_init(&lsmcxt, ctx, len, 0);
+				security_release_secctx(&lsmcxt);
 			}
 		}
 		if (context->ipc.has_perm) {
@@ -1417,6 +1421,7 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
 		char *ctx = NULL;
 		u32 len;
 		struct lsmblob blob;
+		struct lsmcontext lsmcxt;
 
 		lsmblob_init(&blob, n->osid);
 		if (security_secid_to_secctx(&blob, &ctx, &len)) {
@@ -1425,7 +1430,8 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
 				*call_panic = 2;
 		} else {
 			audit_log_format(ab, " obj=%s", ctx);
-			security_release_secctx(ctx, len);
+			lsmcontext_init(&lsmcxt, ctx, len, 0); /* scaffolding */
+			security_release_secctx(&lsmcxt);
 		}
 	}
 
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 2f089733ada7..a7e4c1b34b6c 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -130,6 +130,7 @@ static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb,
 
 static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
 {
+	struct lsmcontext context;
 	struct lsmblob lb;
 	char *secdata;
 	u32 seclen, secid;
@@ -145,7 +146,8 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
 		return;
 
 	put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);
-	security_release_secctx(secdata, seclen);
+	lsmcontext_init(&context, secdata, seclen, 0); /* scaffolding */
+	security_release_secctx(&context);
 }
 
 static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb)
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 9bf1f5460681..89be957f26bd 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -342,6 +342,7 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
 	int len, ret;
 	char *secctx;
 	struct lsmblob blob;
+	struct lsmcontext context;
 
 	/* lsmblob_init() puts ct->secmark into all of the secids in blob.
 	 * security_secid_to_secctx() will know which security module
@@ -362,7 +363,8 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
 
 	ret = 0;
 nla_put_failure:
-	security_release_secctx(secctx, len);
+	lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
+	security_release_secctx(&context);
 	return ret;
 }
 #else
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index 89b6f5ebcfc4..ca2ae290d6ee 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -176,6 +176,7 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
 	u32 len;
 	char *secctx;
 	struct lsmblob blob;
+	struct lsmcontext context;
 
 	lsmblob_init(&blob, ct->secmark);
 	ret = security_secid_to_secctx(&blob, &secctx, &len);
@@ -184,7 +185,8 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
 
 	seq_printf(s, "secctx=%s ", secctx);
 
-	security_release_secctx(secctx, len);
+	lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
+	security_release_secctx(&context);
 }
 #else
 static inline void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index a781e757d593..005900a0c397 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -397,6 +397,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
 	enum ip_conntrack_info ctinfo;
 	struct nfnl_ct_hook *nfnl_ct;
 	bool csum_verify;
+	struct lsmcontext scaff; /* scaffolding */
 	char *secdata = NULL;
 	u32 seclen = 0;
 
@@ -626,8 +627,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
 	}
 
 	nlh->nlmsg_len = skb->len;
-	if (seclen)
-		security_release_secctx(secdata, seclen);
+	if (seclen) {
+		lsmcontext_init(&scaff, secdata, seclen, 0);
+		security_release_secctx(&scaff);
+	}
 	return skb;
 
 nla_put_failure:
@@ -635,8 +638,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
 	kfree_skb(skb);
 	net_err_ratelimited("nf_queue: error creating packet message\n");
 nlmsg_failure:
-	if (seclen)
-		security_release_secctx(secdata, seclen);
+	if (seclen) {
+		lsmcontext_init(&scaff, secdata, seclen, 0);
+		security_release_secctx(&scaff);
+	}
 	return NULL;
 }
 
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 098d0a1a3330..61346aaa2898 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -374,6 +374,7 @@ int netlbl_unlhsh_add(struct net *net,
 	struct net_device *dev;
 	struct netlbl_unlhsh_iface *iface;
 	struct audit_buffer *audit_buf = NULL;
+	struct lsmcontext context;
 	char *secctx = NULL;
 	u32 secctx_len;
 	struct lsmblob blob;
@@ -447,7 +448,9 @@ int netlbl_unlhsh_add(struct net *net,
 					     &secctx,
 					     &secctx_len) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s", secctx);
-			security_release_secctx(secctx, secctx_len);
+			/* scaffolding */
+			lsmcontext_init(&context, secctx, secctx_len, 0);
+			security_release_secctx(&context);
 		}
 		audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);
 		audit_log_end(audit_buf);
@@ -478,6 +481,7 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
 	struct netlbl_unlhsh_addr4 *entry;
 	struct audit_buffer *audit_buf;
 	struct net_device *dev;
+	struct lsmcontext context;
 	char *secctx;
 	u32 secctx_len;
 	struct lsmblob blob;
@@ -509,7 +513,9 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
 		    security_secid_to_secctx(&blob,
 					     &secctx, &secctx_len) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s", secctx);
-			security_release_secctx(secctx, secctx_len);
+			/* scaffolding */
+			lsmcontext_init(&context, secctx, secctx_len, 0);
+			security_release_secctx(&context);
 		}
 		audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
 		audit_log_end(audit_buf);
@@ -546,6 +552,7 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
 	struct netlbl_unlhsh_addr6 *entry;
 	struct audit_buffer *audit_buf;
 	struct net_device *dev;
+	struct lsmcontext context;
 	char *secctx;
 	u32 secctx_len;
 	struct lsmblob blob;
@@ -576,7 +583,8 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
 		    security_secid_to_secctx(&blob,
 					     &secctx, &secctx_len) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s", secctx);
-			security_release_secctx(secctx, secctx_len);
+			lsmcontext_init(&context, secctx, secctx_len, 0);
+			security_release_secctx(&context);
 		}
 		audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
 		audit_log_end(audit_buf);
@@ -1095,6 +1103,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
 	int ret_val = -ENOMEM;
 	struct netlbl_unlhsh_walk_arg *cb_arg = arg;
 	struct net_device *dev;
+	struct lsmcontext context;
 	void *data;
 	u32 secid;
 	char *secctx;
@@ -1165,7 +1174,9 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
 			  NLBL_UNLABEL_A_SECCTX,
 			  secctx_len,
 			  secctx);
-	security_release_secctx(secctx, secctx_len);
+	/* scaffolding */
+	lsmcontext_init(&context, secctx, secctx_len, 0);
+	security_release_secctx(&context);
 	if (ret_val != 0)
 		goto list_cb_failure;
 
diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
index 893301ae0131..ef139d8ae7cd 100644
--- a/net/netlabel/netlabel_user.c
+++ b/net/netlabel/netlabel_user.c
@@ -84,6 +84,7 @@ struct audit_buffer *netlbl_audit_start_common(int type,
 					       struct netlbl_audit *audit_info)
 {
 	struct audit_buffer *audit_buf;
+	struct lsmcontext context;
 	char *secctx;
 	u32 secctx_len;
 	struct lsmblob blob;
@@ -103,7 +104,8 @@ struct audit_buffer *netlbl_audit_start_common(int type,
 	if (audit_info->secid != 0 &&
 	    security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) {
 		audit_log_format(audit_buf, " subj=%s", secctx);
-		security_release_secctx(secctx, secctx_len);
+		lsmcontext_init(&context, secctx, secctx_len, 0);/*scaffolding*/
+		security_release_secctx(&context);
 	}
 
 	return audit_buf;
diff --git a/security/security.c b/security/security.c
index 7829b8f5d15f..4cb540d93ab8 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2361,16 +2361,17 @@ int security_secctx_to_secid(const char *secdata, u32 seclen,
 }
 EXPORT_SYMBOL(security_secctx_to_secid);
 
-void security_release_secctx(char *secdata, u32 seclen)
+void security_release_secctx(struct lsmcontext *cp)
 {
 	struct security_hook_list *hp;
-	int ilsm = lsm_task_ilsm(current);
 
 	hlist_for_each_entry(hp, &security_hook_heads.release_secctx, list)
-		if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot) {
-			hp->hook.release_secctx(secdata, seclen);
-			return;
+		if (cp->slot == hp->lsmid->slot) {
+			hp->hook.release_secctx(cp->context, cp->len);
+			break;
 		}
+
+	memset(cp, 0, sizeof(*cp));
 }
 EXPORT_SYMBOL(security_release_secctx);
 
-- 
2.31.1


^ permalink raw reply related

* [PATCH v28 14/25] LSM: Specify which LSM to display
From: Casey Schaufler @ 2021-07-22  0:47 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel, paul,
	sds, linux-kernel, Stephen Smalley, Greg Kroah-Hartman, linux-api,
	linux-doc
In-Reply-To: <20210722004758.12371-1-casey@schaufler-ca.com>

Create a new entry "interface_lsm" in the procfs attr directory for
controlling which LSM security information is displayed for a
process. A process can only read or write its own display value.

The name of an active LSM that supplies hooks for
human readable data may be written to "interface_lsm" to set the
value. The name of the LSM currently in use can be read from
"interface_lsm". At this point there can only be one LSM capable
of display active. A helper function lsm_task_ilsm() is
provided to get the interface lsm slot for a task_struct.

Setting the "interface_lsm" requires that all security modules using
setprocattr hooks allow the action. Each security module is
responsible for defining its policy.

AppArmor hook provided by John Johansen <john.johansen@canonical.com>
SELinux hook provided by Stephen Smalley <stephen.smalley.work@gmail.com>

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: John Johansen <john.johansen@canonical.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-api@vger.kernel.org
Cc: linux-doc@vger.kernel.org
---
 .../ABI/testing/procfs-attr-lsm_display       |  22 +++
 Documentation/security/lsm.rst                |  14 ++
 fs/proc/base.c                                |   1 +
 include/linux/lsm_hooks.h                     |  17 ++
 security/apparmor/include/apparmor.h          |   3 +-
 security/apparmor/lsm.c                       |  32 ++++
 security/security.c                           | 166 ++++++++++++++++--
 security/selinux/hooks.c                      |  11 ++
 security/selinux/include/classmap.h           |   2 +-
 security/smack/smack_lsm.c                    |   7 +
 10 files changed, 256 insertions(+), 19 deletions(-)
 create mode 100644 Documentation/ABI/testing/procfs-attr-lsm_display

diff --git a/Documentation/ABI/testing/procfs-attr-lsm_display b/Documentation/ABI/testing/procfs-attr-lsm_display
new file mode 100644
index 000000000000..0f60005c235c
--- /dev/null
+++ b/Documentation/ABI/testing/procfs-attr-lsm_display
@@ -0,0 +1,22 @@
+What:		/proc/*/attr/lsm_display
+Contact:	linux-security-module@vger.kernel.org,
+Description:	The name of the Linux security module (LSM) that will
+		provide information in the /proc/*/attr/current,
+		/proc/*/attr/prev and /proc/*/attr/exec interfaces.
+		The details of permissions required to read from
+		this interface are dependent on the LSMs active on the
+		system.
+		A process cannot write to this interface unless it
+		refers to itself.
+		The other details of permissions required to write to
+		this interface are dependent on the LSMs active on the
+		system.
+		The format of the data used by this interface is a
+		text string identifying the name of an LSM. The values
+		accepted are:
+			selinux		- the SELinux LSM
+			smack		- the Smack LSM
+			apparmor	- The AppArmor LSM
+		By convention the LSM names are lower case and do not
+		contain special characters.
+Users:		LSM user-space
diff --git a/Documentation/security/lsm.rst b/Documentation/security/lsm.rst
index 6a2a2e973080..b77b4a540391 100644
--- a/Documentation/security/lsm.rst
+++ b/Documentation/security/lsm.rst
@@ -129,3 +129,17 @@ to identify it as the first security module to be registered.
 The capabilities security module does not use the general security
 blobs, unlike other modules. The reasons are historical and are
 based on overhead, complexity and performance concerns.
+
+LSM External Interfaces
+=======================
+
+The LSM infrastructure does not generally provide external interfaces.
+The individual security modules provide what external interfaces they
+require.
+
+The file ``/sys/kernel/security/lsm`` provides a comma
+separated list of the active security modules.
+
+The file ``/proc/pid/attr/interface_lsm`` contains the name of the security
+module for which the ``/proc/pid/attr/current`` interface will
+apply. This interface can be written to.
diff --git a/fs/proc/base.c b/fs/proc/base.c
index e5b5f7709d48..f80ed1c40053 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2820,6 +2820,7 @@ static const struct pid_entry attr_dir_stuff[] = {
 	ATTR(NULL, "fscreate",		0666),
 	ATTR(NULL, "keycreate",		0666),
 	ATTR(NULL, "sockcreate",	0666),
+	ATTR(NULL, "interface_lsm",	0666),
 #ifdef CONFIG_SECURITY_SMACK
 	DIR("smack",			0555,
 	    proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index c61a16f0a5bc..d2c4bc94d47f 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1686,4 +1686,21 @@ static inline void security_delete_hooks(struct security_hook_list *hooks,
 
 extern int lsm_inode_alloc(struct inode *inode);
 
+/**
+ * lsm_task_ilsm - the "interface_lsm" for this task
+ * @task: The task to report on
+ *
+ * Returns the task's interface LSM slot.
+ */
+static inline int lsm_task_ilsm(struct task_struct *task)
+{
+#ifdef CONFIG_SECURITY
+	int *ilsm = task->security;
+
+	if (ilsm)
+		return *ilsm;
+#endif
+	return LSMBLOB_INVALID;
+}
+
 #endif /* ! __LINUX_LSM_HOOKS_H */
diff --git a/security/apparmor/include/apparmor.h b/security/apparmor/include/apparmor.h
index 1fbabdb565a8..b1622fcb4394 100644
--- a/security/apparmor/include/apparmor.h
+++ b/security/apparmor/include/apparmor.h
@@ -28,8 +28,9 @@
 #define AA_CLASS_SIGNAL		10
 #define AA_CLASS_NET		14
 #define AA_CLASS_LABEL		16
+#define AA_CLASS_DISPLAY_LSM	17
 
-#define AA_CLASS_LAST		AA_CLASS_LABEL
+#define AA_CLASS_LAST		AA_CLASS_DISPLAY_LSM
 
 /* Control parameters settable through module/boot flags */
 extern enum audit_mode aa_g_audit;
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 392e25940d1f..4237536106aa 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -621,6 +621,25 @@ static int apparmor_getprocattr(struct task_struct *task, char *name,
 	return error;
 }
 
+
+static int profile_interface_lsm(struct aa_profile *profile,
+				 struct common_audit_data *sa)
+{
+	struct aa_perms perms = { };
+	unsigned int state;
+
+	state = PROFILE_MEDIATES(profile, AA_CLASS_DISPLAY_LSM);
+	if (state) {
+		aa_compute_perms(profile->policy.dfa, state, &perms);
+		aa_apply_modes_to_perms(profile, &perms);
+		aad(sa)->label = &profile->label;
+
+		return aa_check_perms(profile, &perms, AA_MAY_WRITE, sa, NULL);
+	}
+
+	return 0;
+}
+
 static int apparmor_setprocattr(const char *name, void *value,
 				size_t size)
 {
@@ -632,6 +651,19 @@ static int apparmor_setprocattr(const char *name, void *value,
 	if (size == 0)
 		return -EINVAL;
 
+	/* LSM infrastructure does actual setting of interface_lsm if allowed */
+	if (!strcmp(name, "interface_lsm")) {
+		struct aa_profile *profile;
+		struct aa_label *label;
+
+		aad(&sa)->info = "set interface lsm";
+		label = begin_current_label_crit_section();
+		error = fn_for_each_confined(label, profile,
+					profile_interface_lsm(profile, &sa));
+		end_current_label_crit_section(label);
+		return error;
+	}
+
 	/* AppArmor requires that the buffer must be null terminated atm */
 	if (args[size - 1] != '\0') {
 		/* null terminate */
diff --git a/security/security.c b/security/security.c
index b4a268c1aaec..7829b8f5d15f 100644
--- a/security/security.c
+++ b/security/security.c
@@ -77,7 +77,16 @@ static struct kmem_cache *lsm_file_cache;
 static struct kmem_cache *lsm_inode_cache;
 
 char *lsm_names;
-static struct lsm_blob_sizes blob_sizes __lsm_ro_after_init;
+
+/*
+ * The task blob includes the "interface_lsm" slot used for
+ * chosing which module presents contexts.
+ * Using a long to avoid potential alignment issues with
+ * module assigned task blobs.
+ */
+static struct lsm_blob_sizes blob_sizes __lsm_ro_after_init = {
+	.lbs_task = sizeof(long),
+};
 
 /* Boot-time LSM user choice */
 static __initdata const char *chosen_lsm_order;
@@ -671,6 +680,8 @@ int lsm_inode_alloc(struct inode *inode)
  */
 static int lsm_task_alloc(struct task_struct *task)
 {
+	int *ilsm;
+
 	if (blob_sizes.lbs_task == 0) {
 		task->security = NULL;
 		return 0;
@@ -679,6 +690,15 @@ static int lsm_task_alloc(struct task_struct *task)
 	task->security = kzalloc(blob_sizes.lbs_task, GFP_KERNEL);
 	if (task->security == NULL)
 		return -ENOMEM;
+
+	/*
+	 * The start of the task blob contains the "interface" LSM slot number.
+	 * Start with it set to the invalid slot number, indicating that the
+	 * default first registered LSM be displayed.
+	 */
+	ilsm = task->security;
+	*ilsm = LSMBLOB_INVALID;
+
 	return 0;
 }
 
@@ -1734,14 +1754,26 @@ int security_file_open(struct file *file)
 
 int security_task_alloc(struct task_struct *task, unsigned long clone_flags)
 {
+	int *oilsm = current->security;
+	int *nilsm;
 	int rc = lsm_task_alloc(task);
 
-	if (rc)
+	if (unlikely(rc))
 		return rc;
+
 	rc = call_int_hook(task_alloc, 0, task, clone_flags);
-	if (unlikely(rc))
+	if (unlikely(rc)) {
 		security_task_free(task);
-	return rc;
+		return rc;
+	}
+
+	if (oilsm) {
+		nilsm = task->security;
+		if (nilsm)
+			*nilsm = *oilsm;
+	}
+
+	return 0;
 }
 
 void security_task_free(struct task_struct *task)
@@ -2173,23 +2205,110 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
 				char **value)
 {
 	struct security_hook_list *hp;
+	int ilsm = lsm_task_ilsm(current);
+	int slot = 0;
+
+	if (!strcmp(name, "interface_lsm")) {
+		/*
+		 * lsm_slot will be 0 if there are no displaying modules.
+		 */
+		if (lsm_slot == 0)
+			return -EINVAL;
+
+		/*
+		 * Only allow getting the current process' interface_lsm.
+		 * There are too few reasons to get another process'
+		 * interface_lsm and too many LSM policy issues.
+		 */
+		if (current != p)
+			return -EINVAL;
+
+		ilsm = lsm_task_ilsm(p);
+		if (ilsm != LSMBLOB_INVALID)
+			slot = ilsm;
+		*value = kstrdup(lsm_slotlist[slot]->lsm, GFP_KERNEL);
+		if (*value)
+			return strlen(*value);
+		return -ENOMEM;
+	}
 
 	hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) {
 		if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm))
 			continue;
+		if (lsm == NULL && ilsm != LSMBLOB_INVALID &&
+		    ilsm != hp->lsmid->slot)
+			continue;
 		return hp->hook.getprocattr(p, name, value);
 	}
 	return LSM_RET_DEFAULT(getprocattr);
 }
 
+/**
+ * security_setprocattr - Set process attributes via /proc
+ * @lsm: name of module involved, or NULL
+ * @name: name of the attribute
+ * @value: value to set the attribute to
+ * @size: size of the value
+ *
+ * Set the process attribute for the specified security module
+ * to the specified value. Note that this can only be used to set
+ * the process attributes for the current, or "self" process.
+ * The /proc code has already done this check.
+ *
+ * Returns 0 on success, an appropriate code otherwise.
+ */
 int security_setprocattr(const char *lsm, const char *name, void *value,
 			 size_t size)
 {
 	struct security_hook_list *hp;
+	char *termed;
+	char *copy;
+	int *ilsm = current->security;
+	int rc = -EINVAL;
+	int slot = 0;
+
+	if (!strcmp(name, "interface_lsm")) {
+		/*
+		 * Change the "interface_lsm" value only if all the security
+		 * modules that support setting a procattr allow it.
+		 * It is assumed that all such security modules will be
+		 * cooperative.
+		 */
+		if (size == 0)
+			return -EINVAL;
+
+		hlist_for_each_entry(hp, &security_hook_heads.setprocattr,
+				     list) {
+			rc = hp->hook.setprocattr(name, value, size);
+			if (rc < 0)
+				return rc;
+		}
+
+		rc = -EINVAL;
+
+		copy = kmemdup_nul(value, size, GFP_KERNEL);
+		if (copy == NULL)
+			return -ENOMEM;
+
+		termed = strsep(&copy, " \n");
+
+		for (slot = 0; slot < lsm_slot; slot++)
+			if (!strcmp(termed, lsm_slotlist[slot]->lsm)) {
+				*ilsm = lsm_slotlist[slot]->slot;
+				rc = size;
+				break;
+			}
+
+		kfree(termed);
+		return rc;
+	}
 
 	hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) {
 		if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm))
 			continue;
+		if (lsm == NULL && *ilsm != LSMBLOB_INVALID &&
+		    *ilsm != hp->lsmid->slot)
+			continue;
 		return hp->hook.setprocattr(name, value, size);
 	}
 	return LSM_RET_DEFAULT(setprocattr);
@@ -2209,15 +2328,15 @@ EXPORT_SYMBOL(security_ismaclabel);
 int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen)
 {
 	struct security_hook_list *hp;
-	int rc;
+	int ilsm = lsm_task_ilsm(current);
 
 	hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
 		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
 			continue;
-		rc = hp->hook.secid_to_secctx(blob->secid[hp->lsmid->slot],
-					      secdata, seclen);
-		if (rc != LSM_RET_DEFAULT(secid_to_secctx))
-			return rc;
+		if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot)
+			return hp->hook.secid_to_secctx(
+					blob->secid[hp->lsmid->slot],
+					secdata, seclen);
 	}
 
 	return LSM_RET_DEFAULT(secid_to_secctx);
@@ -2228,16 +2347,15 @@ int security_secctx_to_secid(const char *secdata, u32 seclen,
 			     struct lsmblob *blob)
 {
 	struct security_hook_list *hp;
-	int rc;
+	int ilsm = lsm_task_ilsm(current);
 
 	lsmblob_init(blob, 0);
 	hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list) {
 		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
 			continue;
-		rc = hp->hook.secctx_to_secid(secdata, seclen,
-					      &blob->secid[hp->lsmid->slot]);
-		if (rc != 0)
-			return rc;
+		if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot)
+			return hp->hook.secctx_to_secid(secdata, seclen,
+						&blob->secid[hp->lsmid->slot]);
 	}
 	return 0;
 }
@@ -2245,7 +2363,14 @@ EXPORT_SYMBOL(security_secctx_to_secid);
 
 void security_release_secctx(char *secdata, u32 seclen)
 {
-	call_void_hook(release_secctx, secdata, seclen);
+	struct security_hook_list *hp;
+	int ilsm = lsm_task_ilsm(current);
+
+	hlist_for_each_entry(hp, &security_hook_heads.release_secctx, list)
+		if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot) {
+			hp->hook.release_secctx(secdata, seclen);
+			return;
+		}
 }
 EXPORT_SYMBOL(security_release_secctx);
 
@@ -2386,8 +2511,15 @@ EXPORT_SYMBOL(security_sock_rcv_skb);
 int security_socket_getpeersec_stream(struct socket *sock, char __user *optval,
 				      int __user *optlen, unsigned len)
 {
-	return call_int_hook(socket_getpeersec_stream, -ENOPROTOOPT, sock,
-				optval, optlen, len);
+	int ilsm = lsm_task_ilsm(current);
+	struct security_hook_list *hp;
+
+	hlist_for_each_entry(hp, &security_hook_heads.socket_getpeersec_stream,
+			     list)
+		if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot)
+			return hp->hook.socket_getpeersec_stream(sock, optval,
+								 optlen, len);
+	return -ENOPROTOOPT;
 }
 
 int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb,
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index f84b6c274a10..3b95eb39a3bf 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6500,6 +6500,17 @@ static int selinux_setprocattr(const char *name, void *value, size_t size)
 	/*
 	 * Basic control over ability to set these attributes at all.
 	 */
+
+	/*
+	 * For setting interface_lsm, we only perform a permission check;
+	 * the actual update to the interface_lsm value is handled by the
+	 * LSM framework.
+	 */
+	if (!strcmp(name, "interface_lsm"))
+		return avc_has_perm(&selinux_state,
+				    mysid, mysid, SECCLASS_PROCESS2,
+				    PROCESS2__SETDISPLAY, NULL);
+
 	if (!strcmp(name, "exec"))
 		error = avc_has_perm(&selinux_state,
 				     mysid, mysid, SECCLASS_PROCESS,
diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h
index 62d19bccf3de..8f4b0dd6dd78 100644
--- a/security/selinux/include/classmap.h
+++ b/security/selinux/include/classmap.h
@@ -53,7 +53,7 @@ struct security_class_mapping secclass_map[] = {
 	    "execmem", "execstack", "execheap", "setkeycreate",
 	    "setsockcreate", "getrlimit", NULL } },
 	{ "process2",
-	  { "nnp_transition", "nosuid_transition", NULL } },
+	  { "nnp_transition", "nosuid_transition", "setdisplay", NULL } },
 	{ "system",
 	  { "ipc_info", "syslog_read", "syslog_mod",
 	    "syslog_console", "module_request", "module_load", NULL } },
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 5c10ad27be37..7aa7ea38f627 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3508,6 +3508,13 @@ static int smack_setprocattr(const char *name, void *value, size_t size)
 	struct smack_known_list_elem *sklep;
 	int rc;
 
+	/*
+	 * Allow the /proc/.../attr/current and SO_PEERSEC "interface_lsm"
+	 * to be reset at will.
+	 */
+	if (strcmp(name, "interface_lsm") == 0)
+		return 0;
+
 	if (!smack_privileged(CAP_MAC_ADMIN) && list_empty(&tsp->smk_relabel))
 		return -EPERM;
 
-- 
2.31.1


^ permalink raw reply related

* [PATCH v28 13/25] IMA: Change internal interfaces to use lsmblobs
From: Casey Schaufler @ 2021-07-22  0:47 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel, paul,
	sds, linux-kernel, linux-integrity
In-Reply-To: <20210722004758.12371-1-casey@schaufler-ca.com>

The IMA interfaces ima_get_action() and ima_match_policy()
call LSM functions that use lsmblobs. Change the IMA functions
to pass the lsmblob to be compatible with the LSM functions.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: linux-integrity@vger.kernel.org
To: Mimi Zohar <zohar@linux.ibm.com>
---
 security/integrity/ima/ima.h          |  6 ++---
 security/integrity/ima/ima_api.c      |  6 ++---
 security/integrity/ima/ima_appraise.c |  5 ++--
 security/integrity/ima/ima_main.c     | 36 +++++++++++----------------
 security/integrity/ima/ima_policy.c   | 17 ++++++-------
 5 files changed, 31 insertions(+), 39 deletions(-)

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 55f3bd4f0b01..a6b59fcaf62a 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -251,7 +251,7 @@ static inline void ima_process_queued_keys(void) {}
 
 /* LIM API function definitions */
 int ima_get_action(struct user_namespace *mnt_userns, struct inode *inode,
-		   const struct cred *cred, u32 secid, int mask,
+		   const struct cred *cred, struct lsmblob *blob, int mask,
 		   enum ima_hooks func, int *pcr,
 		   struct ima_template_desc **template_desc,
 		   const char *func_data);
@@ -282,8 +282,8 @@ const char *ima_d_path(const struct path *path, char **pathbuf, char *filename);
 
 /* IMA policy related functions */
 int ima_match_policy(struct user_namespace *mnt_userns, struct inode *inode,
-		     const struct cred *cred, u32 secid, enum ima_hooks func,
-		     int mask, int flags, int *pcr,
+		     const struct cred *cred, struct lsmblob *blob,
+		     enum ima_hooks func, int mask, int flags, int *pcr,
 		     struct ima_template_desc **template_desc,
 		     const char *func_data);
 void ima_init_policy(void);
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index d8e321cc6936..691f68d478f1 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -165,7 +165,7 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
  * @mnt_userns:	user namespace of the mount the inode was found from
  * @inode: pointer to the inode associated with the object being validated
  * @cred: pointer to credentials structure to validate
- * @secid: secid of the task being validated
+ * @blob: LSM data of the task being validated
  * @mask: contains the permission mask (MAY_READ, MAY_WRITE, MAY_EXEC,
  *        MAY_APPEND)
  * @func: caller identifier
@@ -185,7 +185,7 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
  *
  */
 int ima_get_action(struct user_namespace *mnt_userns, struct inode *inode,
-		   const struct cred *cred, u32 secid, int mask,
+		   const struct cred *cred, struct lsmblob *blob, int mask,
 		   enum ima_hooks func, int *pcr,
 		   struct ima_template_desc **template_desc,
 		   const char *func_data)
@@ -194,7 +194,7 @@ int ima_get_action(struct user_namespace *mnt_userns, struct inode *inode,
 
 	flags &= ima_policy_flag;
 
-	return ima_match_policy(mnt_userns, inode, cred, secid, func, mask,
+	return ima_match_policy(mnt_userns, inode, cred, blob, func, mask,
 				flags, pcr, template_desc, func_data);
 }
 
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index e3d903d6e5e7..de50ed4df878 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -77,10 +77,9 @@ int ima_must_appraise(struct user_namespace *mnt_userns, struct inode *inode,
 		return 0;
 
 	security_task_getsecid_subj(current, &blob);
-	/* scaffolding the .secid[0] */
 	return ima_match_policy(mnt_userns, inode, current_cred(),
-				blob.secid[0], func, mask,
-				IMA_APPRAISE | IMA_HASH, NULL, NULL, NULL);
+				&blob, func, mask, IMA_APPRAISE | IMA_HASH,
+				NULL, NULL, NULL);
 }
 
 static int ima_fix_xattr(struct dentry *dentry,
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index de084954d0b9..2bcbfb577860 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -194,8 +194,8 @@ void ima_file_free(struct file *file)
 }
 
 static int process_measurement(struct file *file, const struct cred *cred,
-			       u32 secid, char *buf, loff_t size, int mask,
-			       enum ima_hooks func)
+			       struct lsmblob *blob, char *buf, loff_t size,
+			       int mask, enum ima_hooks func)
 {
 	struct inode *inode = file_inode(file);
 	struct integrity_iint_cache *iint = NULL;
@@ -218,7 +218,7 @@ static int process_measurement(struct file *file, const struct cred *cred,
 	 * bitmask based on the appraise/audit/measurement policy.
 	 * Included is the appraise submask.
 	 */
-	action = ima_get_action(file_mnt_user_ns(file), inode, cred, secid,
+	action = ima_get_action(file_mnt_user_ns(file), inode, cred, blob,
 				mask, func, &pcr, &template_desc, NULL);
 	violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) &&
 			   (ima_policy_flag & IMA_MEASURE));
@@ -392,8 +392,7 @@ int ima_file_mmap(struct file *file, unsigned long prot)
 
 	if (file && (prot & PROT_EXEC)) {
 		security_task_getsecid_subj(current, &blob);
-		/* scaffolding - until process_measurement changes */
-		return process_measurement(file, current_cred(), blob.secid[0],
+		return process_measurement(file, current_cred(), &blob,
 					   NULL, 0, MAY_EXEC, MMAP_CHECK);
 	}
 
@@ -434,7 +433,7 @@ int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot)
 	inode = file_inode(vma->vm_file);
 	/* scaffolding */
 	action = ima_get_action(file_mnt_user_ns(vma->vm_file), inode,
-				current_cred(), blob.secid[0], MAY_EXEC,
+				current_cred(), &blob, MAY_EXEC,
 				MMAP_CHECK, &pcr, &template, NULL);
 
 	/* Is the mmap'ed file in policy? */
@@ -473,16 +472,14 @@ int ima_bprm_check(struct linux_binprm *bprm)
 	struct lsmblob blob;
 
 	security_task_getsecid_subj(current, &blob);
-	/* scaffolding until process_measurement changes */
-	ret = process_measurement(bprm->file, current_cred(), blob.secid[0],
-				  NULL, 0, MAY_EXEC, BPRM_CHECK);
+	ret = process_measurement(bprm->file, current_cred(), &blob, NULL, 0,
+				  MAY_EXEC, BPRM_CHECK);
 	if (ret)
 		return ret;
 
 	security_cred_getsecid(bprm->cred, &blob);
-	/* scaffolding until process_measurement changes */
-	return process_measurement(bprm->file, bprm->cred, blob.secid[0],
-				   NULL, 0, MAY_EXEC, CREDS_CHECK);
+	return process_measurement(bprm->file, bprm->cred, &blob, NULL, 0,
+				   MAY_EXEC, CREDS_CHECK);
 }
 
 /**
@@ -500,8 +497,7 @@ int ima_file_check(struct file *file, int mask)
 	struct lsmblob blob;
 
 	security_task_getsecid_subj(current, &blob);
-	/* scaffolding until process_measurement changes */
-	return process_measurement(file, current_cred(), blob.secid[0], NULL, 0,
+	return process_measurement(file, current_cred(), &blob, NULL, 0,
 				   mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
 					   MAY_APPEND), FILE_CHECK);
 }
@@ -698,9 +694,8 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id,
 	/* Read entire file for all partial reads. */
 	func = read_idmap[read_id] ?: FILE_CHECK;
 	security_task_getsecid_subj(current, &blob);
-	/* scaffolding - until process_measurement changes */
-	return process_measurement(file, current_cred(), blob.secid[0], NULL,
-				   0, MAY_READ, func);
+	return process_measurement(file, current_cred(), &blob, NULL, 0,
+				   MAY_READ, func);
 }
 
 const int read_idmap[READING_MAX_ID] = {
@@ -742,9 +737,8 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
 
 	func = read_idmap[read_id] ?: FILE_CHECK;
 	security_task_getsecid_subj(current, &blob);
-	/* scaffolding until process_measurement changes */
-	return process_measurement(file, current_cred(), blob.secid[0], buf,
-				   size, MAY_READ, func);
+	return process_measurement(file, current_cred(), &blob, buf, size,
+				   MAY_READ, func);
 }
 
 /**
@@ -889,7 +883,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns,
 		security_task_getsecid_subj(current, &blob);
 		/* scaffolding */
 		action = ima_get_action(mnt_userns, inode, current_cred(),
-					blob.secid[0], 0, func, &pcr, &template,
+					&blob, 0, func, &pcr, &template,
 					func_data);
 		if (!(action & IMA_MEASURE))
 			return;
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 6d112ec89c1b..a2b8c0ad8b74 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -548,7 +548,7 @@ static bool ima_match_rule_data(struct ima_rule_entry *rule,
  * @mnt_userns:	user namespace of the mount the inode was found from
  * @inode: a pointer to an inode
  * @cred: a pointer to a credentials structure for user validation
- * @secid: the secid of the task to be validated
+ * @blob: the lsm data of the task to be validated
  * @func: LIM hook identifier
  * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
  * @func_data: func specific data, may be NULL
@@ -558,8 +558,8 @@ static bool ima_match_rule_data(struct ima_rule_entry *rule,
 static bool ima_match_rules(struct ima_rule_entry *rule,
 			    struct user_namespace *mnt_userns,
 			    struct inode *inode, const struct cred *cred,
-			    u32 secid, enum ima_hooks func, int mask,
-			    const char *func_data)
+			    struct lsmblob *blob, enum ima_hooks func,
+			    int mask, const char *func_data)
 {
 	int i;
 
@@ -628,8 +628,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
 		case LSM_SUBJ_USER:
 		case LSM_SUBJ_ROLE:
 		case LSM_SUBJ_TYPE:
-			lsmblob_init(&lsmdata, secid);
-			rc = ima_filter_rule_match(&lsmdata, rule->lsm[i].type,
+			rc = ima_filter_rule_match(blob, rule->lsm[i].type,
 						   Audit_equal,
 						   rule->lsm[i].rule);
 			break;
@@ -673,7 +672,7 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
  * @inode: pointer to an inode for which the policy decision is being made
  * @cred: pointer to a credentials structure for which the policy decision is
  *        being made
- * @secid: LSM secid of the task to be validated
+ * @blob: LSM data of the task to be validated
  * @func: IMA hook identifier
  * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
  * @pcr: set the pcr to extend
@@ -688,8 +687,8 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
  * than writes so ima_match_policy() is classical RCU candidate.
  */
 int ima_match_policy(struct user_namespace *mnt_userns, struct inode *inode,
-		     const struct cred *cred, u32 secid, enum ima_hooks func,
-		     int mask, int flags, int *pcr,
+		     const struct cred *cred, struct lsmblob *blob,
+		     enum ima_hooks func, int mask, int flags, int *pcr,
 		     struct ima_template_desc **template_desc,
 		     const char *func_data)
 {
@@ -705,7 +704,7 @@ int ima_match_policy(struct user_namespace *mnt_userns, struct inode *inode,
 		if (!(entry->action & actmask))
 			continue;
 
-		if (!ima_match_rules(entry, mnt_userns, inode, cred, secid,
+		if (!ima_match_rules(entry, mnt_userns, inode, cred, blob,
 				     func, mask, func_data))
 			continue;
 
-- 
2.31.1


^ permalink raw reply related

* [PATCH v28 12/25] LSM: Use lsmblob in security_cred_getsecid
From: Casey Schaufler @ 2021-07-22  0:47 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel, paul,
	sds, linux-kernel, linux-integrity
In-Reply-To: <20210722004758.12371-1-casey@schaufler-ca.com>

Change the security_cred_getsecid() interface to fill in a
lsmblob instead of a u32 secid. The associated data elements
in the audit sub-system are changed from a secid to a lsmblob
to accommodate multiple possible LSM audit users.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: linux-integrity@vger.kernel.org
Cc: linux-audit@redhat.com
---
 include/linux/security.h          |  2 +-
 kernel/audit.c                    | 25 +++++++----------------
 kernel/audit.h                    |  3 ++-
 kernel/auditsc.c                  | 33 +++++++++++--------------------
 security/integrity/ima/ima_main.c |  8 ++++----
 security/security.c               | 12 ++++++++---
 6 files changed, 35 insertions(+), 48 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index aa19fa4a553f..cdd8d9122795 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -481,7 +481,7 @@ int security_cred_alloc_blank(struct cred *cred, gfp_t gfp);
 void security_cred_free(struct cred *cred);
 int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp);
 void security_transfer_creds(struct cred *new, const struct cred *old);
-void security_cred_getsecid(const struct cred *c, u32 *secid);
+void security_cred_getsecid(const struct cred *c, struct lsmblob *blob);
 int security_kernel_act_as(struct cred *new, struct lsmblob *blob);
 int security_kernel_create_files_as(struct cred *new, struct inode *inode);
 int security_kernel_module_request(char *kmod_name);
diff --git a/kernel/audit.c b/kernel/audit.c
index d92c7b894183..8ec64e6e8bc0 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -125,7 +125,7 @@ static u32	audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
 /* The identity of the user shutting down the audit system. */
 static kuid_t		audit_sig_uid = INVALID_UID;
 static pid_t		audit_sig_pid = -1;
-static u32		audit_sig_sid;
+struct lsmblob		audit_sig_lsm;
 
 /* Records can be lost in several ways:
    0) [suppressed in audit_alloc]
@@ -1441,29 +1441,21 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 	}
 	case AUDIT_SIGNAL_INFO:
 		len = 0;
-		if (audit_sig_sid) {
-			struct lsmblob blob;
-
-			/*
-			 * lsmblob_init sets all values in the lsmblob
-			 * to audit_sig_sid. This is temporary until
-			 * audit_sig_sid is converted to a lsmblob, which
-			 * happens later in this patch set.
-			 */
-			lsmblob_init(&blob, audit_sig_sid);
-			err = security_secid_to_secctx(&blob, &ctx, &len);
+		if (lsmblob_is_set(&audit_sig_lsm)) {
+			err = security_secid_to_secctx(&audit_sig_lsm, &ctx,
+						       &len);
 			if (err)
 				return err;
 		}
 		sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
 		if (!sig_data) {
-			if (audit_sig_sid)
+			if (lsmblob_is_set(&audit_sig_lsm))
 				security_release_secctx(ctx, len);
 			return -ENOMEM;
 		}
 		sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
 		sig_data->pid = audit_sig_pid;
-		if (audit_sig_sid) {
+		if (lsmblob_is_set(&audit_sig_lsm)) {
 			memcpy(sig_data->ctx, ctx, len);
 			security_release_secctx(ctx, len);
 		}
@@ -2352,7 +2344,6 @@ int audit_set_loginuid(kuid_t loginuid)
 int audit_signal_info(int sig, struct task_struct *t)
 {
 	kuid_t uid = current_uid(), auid;
-	struct lsmblob blob;
 
 	if (auditd_test_task(t) &&
 	    (sig == SIGTERM || sig == SIGHUP ||
@@ -2363,9 +2354,7 @@ int audit_signal_info(int sig, struct task_struct *t)
 			audit_sig_uid = auid;
 		else
 			audit_sig_uid = uid;
-		security_task_getsecid_subj(current, &blob);
-		/* scaffolding until audit_sig_sid is converted */
-		audit_sig_sid = blob.secid[0];
+		security_task_getsecid_subj(current, &audit_sig_lsm);
 	}
 
 	return audit_signal_info_syscall(t);
diff --git a/kernel/audit.h b/kernel/audit.h
index b565ea16c0a5..b679517a3030 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -9,6 +9,7 @@
 #include <linux/fs.h>
 #include <linux/audit.h>
 #include <linux/skbuff.h>
+#include <linux/security.h>
 #include <uapi/linux/mqueue.h>
 #include <linux/tty.h>
 
@@ -134,7 +135,7 @@ struct audit_context {
 	kuid_t		    target_auid;
 	kuid_t		    target_uid;
 	unsigned int	    target_sessionid;
-	u32		    target_sid;
+	struct lsmblob	    target_lsm;
 	char		    target_comm[TASK_COMM_LEN];
 
 	struct audit_tree_refs *trees, *first_trees;
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index dcd1b988a2d3..b5807b9b8a4d 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -111,7 +111,7 @@ struct audit_aux_data_pids {
 	kuid_t			target_auid[AUDIT_AUX_PIDS];
 	kuid_t			target_uid[AUDIT_AUX_PIDS];
 	unsigned int		target_sessionid[AUDIT_AUX_PIDS];
-	u32			target_sid[AUDIT_AUX_PIDS];
+	struct lsmblob		target_lsm[AUDIT_AUX_PIDS];
 	char 			target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN];
 	int			pid_count;
 };
@@ -997,14 +997,14 @@ static inline void audit_free_context(struct audit_context *context)
 }
 
 static int audit_log_pid_context(struct audit_context *context, pid_t pid,
-				 kuid_t auid, kuid_t uid, unsigned int sessionid,
-				 u32 sid, char *comm)
+				 kuid_t auid, kuid_t uid,
+				 unsigned int sessionid,
+				 struct lsmblob *blob, char *comm)
 {
 	struct audit_buffer *ab;
 	char *ctx = NULL;
 	u32 len;
 	int rc = 0;
-	struct lsmblob blob;
 
 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
 	if (!ab)
@@ -1013,9 +1013,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
 	audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid,
 			 from_kuid(&init_user_ns, auid),
 			 from_kuid(&init_user_ns, uid), sessionid);
-	if (sid) {
-		lsmblob_init(&blob, sid);
-		if (security_secid_to_secctx(&blob, &ctx, &len)) {
+	if (lsmblob_is_set(blob)) {
+		if (security_secid_to_secctx(blob, &ctx, &len)) {
 			audit_log_format(ab, " obj=(none)");
 			rc = 1;
 		} else {
@@ -1590,7 +1589,7 @@ static void audit_log_exit(void)
 						  axs->target_auid[i],
 						  axs->target_uid[i],
 						  axs->target_sessionid[i],
-						  axs->target_sid[i],
+						  &axs->target_lsm[i],
 						  axs->target_comm[i]))
 				call_panic = 1;
 	}
@@ -1599,7 +1598,7 @@ static void audit_log_exit(void)
 	    audit_log_pid_context(context, context->target_pid,
 				  context->target_auid, context->target_uid,
 				  context->target_sessionid,
-				  context->target_sid, context->target_comm))
+				  &context->target_lsm, context->target_comm))
 			call_panic = 1;
 
 	if (context->pwd.dentry && context->pwd.mnt) {
@@ -1775,7 +1774,7 @@ void __audit_syscall_exit(int success, long return_code)
 	context->aux = NULL;
 	context->aux_pids = NULL;
 	context->target_pid = 0;
-	context->target_sid = 0;
+	lsmblob_init(&context->target_lsm, 0);
 	context->sockaddr_len = 0;
 	context->type = 0;
 	context->fds[0] = -1;
@@ -2434,15 +2433,12 @@ int __audit_sockaddr(int len, void *a)
 void __audit_ptrace(struct task_struct *t)
 {
 	struct audit_context *context = audit_context();
-	struct lsmblob blob;
 
 	context->target_pid = task_tgid_nr(t);
 	context->target_auid = audit_get_loginuid(t);
 	context->target_uid = task_uid(t);
 	context->target_sessionid = audit_get_sessionid(t);
-	security_task_getsecid_obj(t, &blob);
-	/* scaffolding - until target_sid is converted */
-	context->target_sid = blob.secid[0];
+	security_task_getsecid_obj(t, &context->target_lsm);
 	memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
 }
 
@@ -2458,7 +2454,6 @@ int audit_signal_info_syscall(struct task_struct *t)
 	struct audit_aux_data_pids *axp;
 	struct audit_context *ctx = audit_context();
 	kuid_t t_uid = task_uid(t);
-	struct lsmblob blob;
 
 	if (!audit_signals || audit_dummy_context())
 		return 0;
@@ -2470,9 +2465,7 @@ int audit_signal_info_syscall(struct task_struct *t)
 		ctx->target_auid = audit_get_loginuid(t);
 		ctx->target_uid = t_uid;
 		ctx->target_sessionid = audit_get_sessionid(t);
-		security_task_getsecid_obj(t, &blob);
-		/* scaffolding until target_sid is converted */
-		ctx->target_sid = blob.secid[0];
+		security_task_getsecid_obj(t, &ctx->target_lsm);
 		memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
 		return 0;
 	}
@@ -2493,9 +2486,7 @@ int audit_signal_info_syscall(struct task_struct *t)
 	axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
 	axp->target_uid[axp->pid_count] = t_uid;
 	axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
-	security_task_getsecid_obj(t, &blob);
-	/* scaffolding until target_sid is converted */
-	axp->target_sid[axp->pid_count] = blob.secid[0];
+	security_task_getsecid_obj(t, &axp->target_lsm[axp->pid_count]);
 	memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
 	axp->pid_count++;
 
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 29befd24b945..de084954d0b9 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -470,7 +470,6 @@ int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot)
 int ima_bprm_check(struct linux_binprm *bprm)
 {
 	int ret;
-	u32 secid;
 	struct lsmblob blob;
 
 	security_task_getsecid_subj(current, &blob);
@@ -480,9 +479,10 @@ int ima_bprm_check(struct linux_binprm *bprm)
 	if (ret)
 		return ret;
 
-	security_cred_getsecid(bprm->cred, &secid);
-	return process_measurement(bprm->file, bprm->cred, secid, NULL, 0,
-				   MAY_EXEC, CREDS_CHECK);
+	security_cred_getsecid(bprm->cred, &blob);
+	/* scaffolding until process_measurement changes */
+	return process_measurement(bprm->file, bprm->cred, blob.secid[0],
+				   NULL, 0, MAY_EXEC, CREDS_CHECK);
 }
 
 /**
diff --git a/security/security.c b/security/security.c
index da85932a4d53..b4a268c1aaec 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1798,10 +1798,16 @@ void security_transfer_creds(struct cred *new, const struct cred *old)
 	call_void_hook(cred_transfer, new, old);
 }
 
-void security_cred_getsecid(const struct cred *c, u32 *secid)
+void security_cred_getsecid(const struct cred *c, struct lsmblob *blob)
 {
-	*secid = 0;
-	call_void_hook(cred_getsecid, c, secid);
+	struct security_hook_list *hp;
+
+	lsmblob_init(blob, 0);
+	hlist_for_each_entry(hp, &security_hook_heads.cred_getsecid, list) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		hp->hook.cred_getsecid(c, &blob->secid[hp->lsmid->slot]);
+	}
 }
 EXPORT_SYMBOL(security_cred_getsecid);
 
-- 
2.31.1


^ permalink raw reply related

* [PATCH v28 11/25] LSM: Use lsmblob in security_inode_getsecid
From: Casey Schaufler @ 2021-07-22  0:47 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel, paul,
	sds, linux-kernel, linux-integrity
In-Reply-To: <20210722004758.12371-1-casey@schaufler-ca.com>

Change the security_inode_getsecid() interface to fill in a
lsmblob structure instead of a u32 secid. This allows for its
callers to gather data from all registered LSMs. Data is provided
for IMA and audit.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: linux-integrity@vger.kernel.org
Cc: linux-audit@redhat.com
---
 include/linux/security.h            |  7 ++++---
 kernel/auditsc.c                    |  6 +++++-
 security/integrity/ima/ima_policy.c |  4 +---
 security/security.c                 | 11 +++++++++--
 4 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index 4070cef152f7..aa19fa4a553f 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -454,7 +454,7 @@ int security_inode_getsecurity(struct user_namespace *mnt_userns,
 			       void **buffer, bool alloc);
 int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags);
 int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size);
-void security_inode_getsecid(struct inode *inode, u32 *secid);
+void security_inode_getsecid(struct inode *inode, struct lsmblob *blob);
 int security_inode_copy_up(struct dentry *src, struct cred **new);
 int security_inode_copy_up_xattr(const char *name);
 int security_kernfs_init_security(struct kernfs_node *kn_dir,
@@ -1005,9 +1005,10 @@ static inline int security_inode_listsecurity(struct inode *inode, char *buffer,
 	return 0;
 }
 
-static inline void security_inode_getsecid(struct inode *inode, u32 *secid)
+static inline void security_inode_getsecid(struct inode *inode,
+					   struct lsmblob *blob)
 {
-	*secid = 0;
+	lsmblob_init(blob, 0);
 }
 
 static inline int security_inode_copy_up(struct dentry *src, struct cred **new)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 50e3f2f4cb49..dcd1b988a2d3 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1975,13 +1975,17 @@ static void audit_copy_inode(struct audit_names *name,
 			     const struct dentry *dentry,
 			     struct inode *inode, unsigned int flags)
 {
+	struct lsmblob blob;
+
 	name->ino   = inode->i_ino;
 	name->dev   = inode->i_sb->s_dev;
 	name->mode  = inode->i_mode;
 	name->uid   = inode->i_uid;
 	name->gid   = inode->i_gid;
 	name->rdev  = inode->i_rdev;
-	security_inode_getsecid(inode, &name->osid);
+	security_inode_getsecid(inode, &blob);
+	/* scaffolding until osid is updated */
+	name->osid = blob.secid[0];
 	if (flags & AUDIT_INODE_NOEVAL) {
 		name->fcap_ver = -1;
 		return;
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index af612a42eebe..6d112ec89c1b 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -608,7 +608,6 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
 		return false;
 	for (i = 0; i < MAX_LSM_RULES; i++) {
 		int rc = 0;
-		u32 osid;
 		struct lsmblob lsmdata;
 
 		if (!ima_lsm_isset(rule, i)) {
@@ -621,8 +620,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
 		case LSM_OBJ_USER:
 		case LSM_OBJ_ROLE:
 		case LSM_OBJ_TYPE:
-			security_inode_getsecid(inode, &osid);
-			lsmblob_init(&lsmdata, osid);
+			security_inode_getsecid(inode, &lsmdata);
 			rc = ima_filter_rule_match(&lsmdata, rule->lsm[i].type,
 						   Audit_equal,
 						   rule->lsm[i].rule);
diff --git a/security/security.c b/security/security.c
index 458fded340ab..da85932a4d53 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1548,9 +1548,16 @@ int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer
 }
 EXPORT_SYMBOL(security_inode_listsecurity);
 
-void security_inode_getsecid(struct inode *inode, u32 *secid)
+void security_inode_getsecid(struct inode *inode, struct lsmblob *blob)
 {
-	call_void_hook(inode_getsecid, inode, secid);
+	struct security_hook_list *hp;
+
+	lsmblob_init(blob, 0);
+	hlist_for_each_entry(hp, &security_hook_heads.inode_getsecid, list) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		hp->hook.inode_getsecid(inode, &blob->secid[hp->lsmid->slot]);
+	}
 }
 
 int security_inode_copy_up(struct dentry *src, struct cred **new)
-- 
2.31.1


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