From a4e3b8d79a5c6d40f4a9703abf7fe3abcc6c3b8d Mon Sep 17 00:00:00 2001
From: Mimi Zohar <zohar@linux.vnet.ibm.com>
Date: Thu, 22 May 2014 14:02:23 -0400
Subject: [PATCH 1/6] KEYS: special dot prefixed keyring name bug fix

Dot prefixed keyring names are supposed to be reserved for the
kernel, but add_key() calls key_get_type_from_user(), which
incorrectly verifies the 'type' field, not the 'description' field.
This patch verifies the 'description' field isn't dot prefixed,
when creating a new keyring, and removes the dot prefix test in
key_get_type_from_user().

Changelog v6:
- whitespace and other cleanup

Changelog v5:
- Only prevent userspace from creating a dot prefixed keyring, not
  regular keys  - Dmitry

Reported-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
---
 security/keys/keyctl.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index cd5bd0cef25d..8a8c23357291 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -37,8 +37,6 @@ static int key_get_type_from_user(char *type,
 		return ret;
 	if (ret == 0 || ret >= len)
 		return -EINVAL;
-	if (type[0] == '.')
-		return -EPERM;
 	type[len - 1] = '\0';
 	return 0;
 }
@@ -86,6 +84,10 @@ SYSCALL_DEFINE5(add_key, const char __user *, _type,
 		if (!*description) {
 			kfree(description);
 			description = NULL;
+		} else if ((description[0] == '.') &&
+			   (strncmp(type, "keyring", 7) == 0)) {
+			ret = -EPERM;
+			goto error2;
 		}
 	}
 

From 3be4beaf7c91ec9c6fefa5f11173af37113d10ae Mon Sep 17 00:00:00 2001
From: Mimi Zohar <zohar@linux.vnet.ibm.com>
Date: Tue, 20 Aug 2013 14:36:27 -0400
Subject: [PATCH 2/6] KEYS: verify a certificate is signed by a 'trusted' key

Only public keys, with certificates signed by an existing
'trusted' key on the system trusted keyring, should be added
to a trusted keyring.  This patch adds support for verifying
a certificate's signature.

This is derived from David Howells pkcs7_request_asymmetric_key() patch.

Changelog v6:
- on error free key - Dmitry
- validate trust only for not already trusted keys - Dmitry
- formatting cleanup

Changelog:
- define get_system_trusted_keyring() to fix kbuild issues

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
---
 crypto/asymmetric_keys/x509_public_key.c | 87 +++++++++++++++++++++++-
 include/keys/system_keyring.h            | 10 ++-
 2 files changed, 95 insertions(+), 2 deletions(-)

diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index 382ef0d2ff2e..436fbd8552fc 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -18,11 +18,61 @@
 #include <linux/asn1_decoder.h>
 #include <keys/asymmetric-subtype.h>
 #include <keys/asymmetric-parser.h>
+#include <keys/system_keyring.h>
 #include <crypto/hash.h>
 #include "asymmetric_keys.h"
 #include "public_key.h"
 #include "x509_parser.h"
 
+/*
+ * Find a key in the given keyring by issuer and authority.
+ */
+static struct key *x509_request_asymmetric_key(struct key *keyring,
+					       const char *signer,
+					       size_t signer_len,
+					       const char *authority,
+					       size_t auth_len)
+{
+	key_ref_t key;
+	char *id;
+
+	/* Construct an identifier. */
+	id = kmalloc(signer_len + 2 + auth_len + 1, GFP_KERNEL);
+	if (!id)
+		return ERR_PTR(-ENOMEM);
+
+	memcpy(id, signer, signer_len);
+	id[signer_len + 0] = ':';
+	id[signer_len + 1] = ' ';
+	memcpy(id + signer_len + 2, authority, auth_len);
+	id[signer_len + 2 + auth_len] = 0;
+
+	pr_debug("Look up: \"%s\"\n", id);
+
+	key = keyring_search(make_key_ref(keyring, 1),
+			     &key_type_asymmetric, id);
+	if (IS_ERR(key))
+		pr_debug("Request for module key '%s' err %ld\n",
+			 id, PTR_ERR(key));
+	kfree(id);
+
+	if (IS_ERR(key)) {
+		switch (PTR_ERR(key)) {
+			/* Hide some search errors */
+		case -EACCES:
+		case -ENOTDIR:
+		case -EAGAIN:
+			return ERR_PTR(-ENOKEY);
+		default:
+			return ERR_CAST(key);
+		}
+	}
+
+	pr_devel("<==%s() = 0 [%x]\n", __func__,
+		 key_serial(key_ref_to_ptr(key)));
+	return key_ref_to_ptr(key);
+}
+
 /*
  * Set up the signature parameters in an X.509 certificate.  This involves
  * digesting the signed data and extracting the signature.
@@ -102,6 +152,37 @@ int x509_check_signature(const struct public_key *pub,
 }
 EXPORT_SYMBOL_GPL(x509_check_signature);
 
+/*
+ * Check the new certificate against the ones in the trust keyring.  If one of
+ * those is the signing key and validates the new certificate, then mark the
+ * new certificate as being trusted.
+ *
+ * Return 0 if the new certificate was successfully validated, 1 if we couldn't
+ * find a matching parent certificate in the trusted list and an error if there
+ * is a matching certificate but the signature check fails.
+ */
+static int x509_validate_trust(struct x509_certificate *cert,
+			       struct key *trust_keyring)
+{
+	const struct public_key *pk;
+	struct key *key;
+	int ret = 1;
+
+	if (!trust_keyring)
+		return -EOPNOTSUPP;
+
+	key = x509_request_asymmetric_key(trust_keyring,
+					  cert->issuer, strlen(cert->issuer),
+					  cert->authority,
+					  strlen(cert->authority));
+	if (!IS_ERR(key))  {
+		pk = key->payload.data;
+		ret = x509_check_signature(pk, cert);
+		key_put(key);
+	}
+	return ret;
+}
+
 /*
  * Attempt to parse a data blob for a key as an X509 certificate.
  */
@@ -155,9 +236,13 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
 	/* Check the signature on the key if it appears to be self-signed */
 	if (!cert->authority ||
 	    strcmp(cert->fingerprint, cert->authority) == 0) {
-		ret = x509_check_signature(cert->pub, cert);
+		ret = x509_check_signature(cert->pub, cert); /* self-signed */
 		if (ret < 0)
 			goto error_free_cert;
+	} else if (!prep->trusted) {
+		ret = x509_validate_trust(cert, get_system_trusted_keyring());
+		if (!ret)
+			prep->trusted = 1;
 	}
 
 	/* Propose a description */
diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h
index 8dabc399bd1d..72665eb80692 100644
--- a/include/keys/system_keyring.h
+++ b/include/keys/system_keyring.h
@@ -17,7 +17,15 @@
 #include <linux/key.h>
 
 extern struct key *system_trusted_keyring;
-
+static inline struct key *get_system_trusted_keyring(void)
+{
+	return system_trusted_keyring;
+}
+#else
+static inline struct key *get_system_trusted_keyring(void)
+{
+	return NULL;
+}
 #endif
 
 #endif /* _KEYS_SYSTEM_KEYRING_H */

From b3426827c848d252ed4ca5f4d3085551be083e12 Mon Sep 17 00:00:00 2001
From: Dmitry Kasatkin <d.kasatkin@samsung.com>
Date: Tue, 17 Jun 2014 11:56:57 +0300
Subject: [PATCH 3/6] KEYS: make partial key id matching as a dedicated
 function

To avoid code duplication this patch refactors asymmetric_key_match(),
making partial ID string match a separate function.

This patch also implicitly fixes a bug in the code.  asymmetric_key_match()
allows to match the key by its subtype. But subtype matching could be
undone if asymmetric_key_id(key) would return NULL. This patch first
checks for matching spec and then for its value.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
---
 crypto/asymmetric_keys/asymmetric_keys.h |  2 +
 crypto/asymmetric_keys/asymmetric_type.c | 50 +++++++++++++++---------
 2 files changed, 33 insertions(+), 19 deletions(-)

diff --git a/crypto/asymmetric_keys/asymmetric_keys.h b/crypto/asymmetric_keys/asymmetric_keys.h
index 515b63430812..a63c551c6557 100644
--- a/crypto/asymmetric_keys/asymmetric_keys.h
+++ b/crypto/asymmetric_keys/asymmetric_keys.h
@@ -9,6 +9,8 @@
  * 2 of the Licence, or (at your option) any later version.
  */
 
+int asymmetric_keyid_match(const char *kid, const char *id);
+
 static inline const char *asymmetric_key_id(const struct key *key)
 {
 	return key->type_data.p[1];
diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c
index b77eb5304788..1fd1d304a15a 100644
--- a/crypto/asymmetric_keys/asymmetric_type.c
+++ b/crypto/asymmetric_keys/asymmetric_type.c
@@ -22,6 +22,34 @@ MODULE_LICENSE("GPL");
 static LIST_HEAD(asymmetric_key_parsers);
 static DECLARE_RWSEM(asymmetric_key_parsers_sem);
 
+/*
+ * Match asymmetric key id with partial match
+ * @id:		key id to match in a form "id:<id>"
+ */
+int asymmetric_keyid_match(const char *kid, const char *id)
+{
+	size_t idlen, kidlen;
+
+	if (!kid || !id)
+		return 0;
+
+	/* make it possible to use id as in the request: "id:<id>" */
+	if (strncmp(id, "id:", 3) == 0)
+		id += 3;
+
+	/* Anything after here requires a partial match on the ID string */
+	idlen = strlen(id);
+	kidlen = strlen(kid);
+	if (idlen > kidlen)
+		return 0;
+
+	kid += kidlen - idlen;
+	if (strcasecmp(id, kid) != 0)
+		return 0;
+
+	return 1;
+}
+
 /*
  * Match asymmetric keys on (part of) their name
  * We have some shorthand methods for matching keys.  We allow:
@@ -34,9 +62,8 @@ static int asymmetric_key_match(const struct key *key, const void *description)
 {
 	const struct asymmetric_key_subtype *subtype = asymmetric_key_subtype(key);
 	const char *spec = description;
-	const char *id, *kid;
+	const char *id;
 	ptrdiff_t speclen;
-	size_t idlen, kidlen;
 
 	if (!subtype || !spec || !*spec)
 		return 0;
@@ -55,23 +82,8 @@ static int asymmetric_key_match(const struct key *key, const void *description)
 	speclen = id - spec;
 	id++;
 
-	/* Anything after here requires a partial match on the ID string */
-	kid = asymmetric_key_id(key);
-	if (!kid)
-		return 0;
-
-	idlen = strlen(id);
-	kidlen = strlen(kid);
-	if (idlen > kidlen)
-		return 0;
-
-	kid += kidlen - idlen;
-	if (strcasecmp(id, kid) != 0)
-		return 0;
-
-	if (speclen == 2 &&
-	    memcmp(spec, "id", 2) == 0)
-		return 1;
+	if (speclen == 2 && memcmp(spec, "id", 2) == 0)
+		return asymmetric_keyid_match(asymmetric_key_id(key), id);
 
 	if (speclen == subtype->name_len &&
 	    memcmp(spec, subtype->name, speclen) == 0)

From ffb70f61bab1482a3bd0f85fd8f1e9c9909df2ca Mon Sep 17 00:00:00 2001
From: Dmitry Kasatkin <d.kasatkin@samsung.com>
Date: Tue, 17 Jun 2014 11:56:58 +0300
Subject: [PATCH 4/6] KEYS: validate certificate trust only with selected key

Instead of allowing public keys, with certificates signed by any
key on the system trusted keyring, to be added to a trusted keyring,
this patch further restricts the certificates to those signed by a
particular key on the system keyring.

This patch defines a new kernel parameter 'ca_keys' to identify the
specific key which must be used for trust validation of certificates.

Simplified Mimi's "KEYS: define an owner trusted keyring" patch.

Changelog:
- support for builtin x509 public keys only
- export "asymmetric_keyid_match"
- remove ifndefs MODULE
- rename kernel boot parameter from keys_ownerid to ca_keys

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
---
 Documentation/kernel-parameters.txt      |  5 +++++
 crypto/asymmetric_keys/asymmetric_type.c |  1 +
 crypto/asymmetric_keys/x509_public_key.c | 19 +++++++++++++++++++
 3 files changed, 25 insertions(+)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 8b2ab548b6e4..bdb193afe176 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -566,6 +566,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			possible to determine what the correct size should be.
 			This option provides an override for these situations.
 
+	ca_keys=	[KEYS] This parameter identifies a specific key(s) on
+			the system trusted keyring to be used for certificate
+			trust validation.
+			format: id:<keyid>
+
 	ccw_timeout_log [S390]
 			See Documentation/s390/CommonIO for details.
 
diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c
index 1fd1d304a15a..c948df5c4ecd 100644
--- a/crypto/asymmetric_keys/asymmetric_type.c
+++ b/crypto/asymmetric_keys/asymmetric_type.c
@@ -49,6 +49,7 @@ int asymmetric_keyid_match(const char *kid, const char *id)
 
 	return 1;
 }
+EXPORT_SYMBOL_GPL(asymmetric_keyid_match);
 
 /*
  * Match asymmetric keys on (part of) their name
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index 436fbd8552fc..d376195e1d08 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -24,6 +24,22 @@
 #include "public_key.h"
 #include "x509_parser.h"
 
+static char *ca_keyid;
+
+#ifndef MODULE
+static int __init ca_keys_setup(char *str)
+{
+	if (!str)		/* default system keyring */
+		return 1;
+
+	if (strncmp(str, "id:", 3) == 0)
+		ca_keyid = str;	/* owner key 'id:xxxxxx' */
+
+	return 1;
+}
+__setup("ca_keys=", ca_keys_setup);
+#endif
+
 /*
  * Find a key in the given keyring by issuer and authority.
  */
@@ -171,6 +187,9 @@ static int x509_validate_trust(struct x509_certificate *cert,
 	if (!trust_keyring)
 		return -EOPNOTSUPP;
 
+	if (ca_keyid && !asymmetric_keyid_match(cert->authority, ca_keyid))
+		return -EPERM;
+
 	key = x509_request_asymmetric_key(trust_keyring,
 					  cert->issuer, strlen(cert->issuer),
 					  cert->authority,

From 32c4741cb66703a3c282f41d77deff4afd93342a Mon Sep 17 00:00:00 2001
From: Dmitry Kasatkin <d.kasatkin@samsung.com>
Date: Tue, 17 Jun 2014 11:56:59 +0300
Subject: [PATCH 5/6] KEYS: validate certificate trust only with builtin keys

Instead of allowing public keys, with certificates signed by any
key on the system trusted keyring, to be added to a trusted keyring,
this patch further restricts the certificates to those signed only by
builtin keys on the system keyring.

This patch defines a new option 'builtin' for the kernel parameter
'keys_ownerid' to allow trust validation using builtin keys.

Simplified Mimi's "KEYS: define an owner trusted keyring" patch

Changelog v7:
- rename builtin_keys to use_builtin_keys

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
---
 Documentation/kernel-parameters.txt      | 2 +-
 crypto/asymmetric_keys/x509_public_key.c | 9 ++++++---
 include/linux/key.h                      | 1 +
 kernel/system_keyring.c                  | 1 +
 4 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index bdb193afe176..90c12c591168 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -569,7 +569,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 	ca_keys=	[KEYS] This parameter identifies a specific key(s) on
 			the system trusted keyring to be used for certificate
 			trust validation.
-			format: id:<keyid>
+			format: { id:<keyid> | builtin }
 
 	ccw_timeout_log [S390]
 			See Documentation/s390/CommonIO for details.
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index d376195e1d08..927ce755ff67 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -24,6 +24,7 @@
 #include "public_key.h"
 #include "x509_parser.h"
 
+static bool use_builtin_keys;
 static char *ca_keyid;
 
 #ifndef MODULE
@@ -34,6 +35,8 @@ static int __init ca_keys_setup(char *str)
 
 	if (strncmp(str, "id:", 3) == 0)
 		ca_keyid = str;	/* owner key 'id:xxxxxx' */
+	else if (strcmp(str, "builtin") == 0)
+		use_builtin_keys = true;
 
 	return 1;
 }
@@ -180,7 +183,6 @@ EXPORT_SYMBOL_GPL(x509_check_signature);
 static int x509_validate_trust(struct x509_certificate *cert,
 			       struct key *trust_keyring)
 {
-	const struct public_key *pk;
 	struct key *key;
 	int ret = 1;
 
@@ -195,8 +197,9 @@ static int x509_validate_trust(struct x509_certificate *cert,
 					  cert->authority,
 					  strlen(cert->authority));
 	if (!IS_ERR(key))  {
-		pk = key->payload.data;
-		ret = x509_check_signature(pk, cert);
+		if (!use_builtin_keys
+		    || test_bit(KEY_FLAG_BUILTIN, &key->flags))
+			ret = x509_check_signature(key->payload.data, cert);
 		key_put(key);
 	}
 	return ret;
diff --git a/include/linux/key.h b/include/linux/key.h
index 017b0826642f..65316f7ae794 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -170,6 +170,7 @@ struct key {
 #define KEY_FLAG_INVALIDATED	7	/* set if key has been invalidated */
 #define KEY_FLAG_TRUSTED	8	/* set if key is trusted */
 #define KEY_FLAG_TRUSTED_ONLY	9	/* set if keyring only accepts links to trusted keys */
+#define KEY_FLAG_BUILTIN	10	/* set if key is builtin */
 
 	/* the key type and key description string
 	 * - the desc is used to match a key against search criteria
diff --git a/kernel/system_keyring.c b/kernel/system_keyring.c
index 52ebc70263f4..875f64e8935b 100644
--- a/kernel/system_keyring.c
+++ b/kernel/system_keyring.c
@@ -89,6 +89,7 @@ static __init int load_system_certificate_list(void)
 			pr_err("Problem loading in-kernel X.509 certificate (%ld)\n",
 			       PTR_ERR(key));
 		} else {
+			set_bit(KEY_FLAG_BUILTIN, &key_ref_to_ptr(key)->flags);
 			pr_notice("Loaded X.509 cert '%s'\n",
 				  key_ref_to_ptr(key)->description);
 			key_ref_put(key);

From 7d2ce2320e8efdc4a6dcbae7b329ed3f0d1cd778 Mon Sep 17 00:00:00 2001
From: Mimi Zohar <zohar@linux.vnet.ibm.com>
Date: Tue, 13 Aug 2013 08:47:43 -0400
Subject: [PATCH 6/6] ima: define '.ima' as a builtin 'trusted' keyring

Require all keys added to the IMA keyring be signed by an
existing trusted key on the system trusted keyring.

Changelog v6:
- remove ifdef CONFIG_IMA_TRUSTED_KEYRING in C code - Dmitry
- update Kconfig dependency and help
- select KEYS_DEBUG_PROC_KEYS - Dmitry

Changelog v5:
- Move integrity_init_keyring() to init_ima() - Dmitry
- reset keyring[id] on failure - Dmitry

Changelog v1:
- don't link IMA trusted keyring to user keyring

Changelog:
- define stub integrity_init_keyring() function (reported-by Fengguang Wu)
- differentiate between regular and trusted keyring names.
- replace printk with pr_info (D. Kasatkin)
- only make the IMA keyring a trusted keyring (reported-by D. Kastatkin)
- define stub integrity_init_keyring() definition based on
  CONFIG_INTEGRITY_SIGNATURE, not CONFIG_INTEGRITY_ASYMMETRIC_KEYS.
  (reported-by Jim Davis)

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Acked-by: David Howells <dhowells@redhat.com>
---
 security/integrity/digsig.c       | 28 ++++++++++++++++++++++++++++
 security/integrity/ima/Kconfig    | 10 ++++++++++
 security/integrity/ima/ima.h      | 12 ++++++++++++
 security/integrity/ima/ima_main.c | 10 ++++++++--
 security/integrity/integrity.h    |  5 +++++
 5 files changed, 63 insertions(+), 2 deletions(-)

diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index b4af4ebc5be2..8d4fbff8b87c 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -13,7 +13,9 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/err.h>
+#include <linux/sched.h>
 #include <linux/rbtree.h>
+#include <linux/cred.h>
 #include <linux/key-type.h>
 #include <linux/digsig.h>
 
@@ -24,7 +26,11 @@ static struct key *keyring[INTEGRITY_KEYRING_MAX];
 static const char *keyring_name[INTEGRITY_KEYRING_MAX] = {
 	"_evm",
 	"_module",
+#ifndef CONFIG_IMA_TRUSTED_KEYRING
 	"_ima",
+#else
+	".ima",
+#endif
 };
 
 int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
@@ -56,3 +62,25 @@ int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
 
 	return -EOPNOTSUPP;
 }
+
+int integrity_init_keyring(const unsigned int id)
+{
+	const struct cred *cred = current_cred();
+	int err = 0;
+
+	keyring[id] = keyring_alloc(keyring_name[id], KUIDT_INIT(0),
+				    KGIDT_INIT(0), cred,
+				    ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
+				     KEY_USR_VIEW | KEY_USR_READ |
+				     KEY_USR_WRITE | KEY_USR_SEARCH),
+				    KEY_ALLOC_NOT_IN_QUOTA, NULL);
+	if (!IS_ERR(keyring[id]))
+		set_bit(KEY_FLAG_TRUSTED_ONLY, &keyring[id]->flags);
+	else {
+		err = PTR_ERR(keyring[id]);
+		pr_info("Can't allocate %s keyring (%d)\n",
+			keyring_name[id], err);
+		keyring[id] = NULL;
+	}
+	return err;
+}
diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig
index 81a27971d884..08758fbd496f 100644
--- a/security/integrity/ima/Kconfig
+++ b/security/integrity/ima/Kconfig
@@ -123,3 +123,13 @@ config IMA_APPRAISE
 	  For more information on integrity appraisal refer to:
 	  <http://linux-ima.sourceforge.net>
 	  If unsure, say N.
+
+config IMA_TRUSTED_KEYRING
+	bool "Require all keys on the .ima keyring be signed"
+	depends on IMA_APPRAISE && SYSTEM_TRUSTED_KEYRING
+	depends on INTEGRITY_ASYMMETRIC_KEYS
+	select KEYS_DEBUG_PROC_KEYS
+	default y
+	help
+	   This option requires that all keys added to the .ima
+	   keyring be signed by a key on the system trusted keyring.
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index f79fa8be203c..c42056edfc97 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -249,4 +249,16 @@ static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
 	return -EINVAL;
 }
 #endif /* CONFIG_IMA_LSM_RULES */
+
+#ifdef CONFIG_IMA_TRUSTED_KEYRING
+static inline int ima_init_keyring(const unsigned int id)
+{
+	return integrity_init_keyring(id);
+}
+#else
+static inline int ima_init_keyring(const unsigned int id)
+{
+	return 0;
+}
+#endif /* CONFIG_IMA_TRUSTED_KEYRING */
 #endif
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index f474c608fa11..0d696431209c 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -325,8 +325,14 @@ static int __init init_ima(void)
 
 	hash_setup(CONFIG_IMA_DEFAULT_HASH);
 	error = ima_init();
-	if (!error)
-		ima_initialized = 1;
+	if (error)
+		goto out;
+
+	error = ima_init_keyring(INTEGRITY_KEYRING_IMA);
+	if (error)
+		goto out;
+	ima_initialized = 1;
+out:
 	return error;
 }
 
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index 33c0a70f6b15..09c440d9aaee 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -124,6 +124,7 @@ struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
 int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
 			    const char *digest, int digestlen);
 
+int integrity_init_keyring(const unsigned int id);
 #else
 
 static inline int integrity_digsig_verify(const unsigned int id,
@@ -133,6 +134,10 @@ static inline int integrity_digsig_verify(const unsigned int id,
 	return -EOPNOTSUPP;
 }
 
+static inline int integrity_init_keyring(const unsigned int id)
+{
+	return 0;
+}
 #endif /* CONFIG_INTEGRITY_SIGNATURE */
 
 #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS