Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity into next

23 files changed, 657 insertions, 84 deletions

diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index 2a44b3752471..9e9e5a6a9ed6 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -321,6 +321,8 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
 			goto error_free_cert;
 	} else if (!prep->trusted) {
 		ret = x509_validate_trust(cert, get_system_trusted_keyring());
+		if (ret)
+			ret = x509_validate_trust(cert, get_ima_mok_keyring());
 		if (!ret)
 			prep->trusted = 1;
 	}
diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h
index b20cd885c1fd..39fd38cfa8c9 100644
--- a/include/keys/system_keyring.h
+++ b/include/keys/system_keyring.h
@@ -35,4 +35,28 @@ extern int system_verify_data(const void *data, unsigned long len,
 			      enum key_being_used_for usage);
 #endif
 
+#ifdef CONFIG_IMA_MOK_KEYRING
+extern struct key *ima_mok_keyring;
+extern struct key *ima_blacklist_keyring;
+
+static inline struct key *get_ima_mok_keyring(void)
+{
+	return ima_mok_keyring;
+}
+static inline struct key *get_ima_blacklist_keyring(void)
+{
+	return ima_blacklist_keyring;
+}
+#else
+static inline struct key *get_ima_mok_keyring(void)
+{
+	return NULL;
+}
+static inline struct key *get_ima_blacklist_keyring(void)
+{
+	return NULL;
+}
+#endif /* CONFIG_IMA_MOK_KEYRING */
+
+
 #endif /* _KEYS_SYSTEM_KEYRING_H */
diff --git a/include/linux/evm.h b/include/linux/evm.h
index 1fcb88ca88de..35ed9a8a403a 100644
--- a/include/linux/evm.h
+++ b/include/linux/evm.h
@@ -14,6 +14,7 @@
 struct integrity_iint_cache;
 
 #ifdef CONFIG_EVM
+extern int evm_set_key(void *key, size_t keylen);
 extern enum integrity_status evm_verifyxattr(struct dentry *dentry,
 					     const char *xattr_name,
 					     void *xattr_value,
@@ -42,6 +43,12 @@ static inline int posix_xattr_acl(const char *xattrname)
 }
 #endif
 #else
+
+static inline int evm_set_key(void *key, size_t keylen)
+{
+	return -EOPNOTSUPP;
+}
+
 #ifdef CONFIG_INTEGRITY
 static inline enum integrity_status evm_verifyxattr(struct dentry *dentry,
 						    const char *xattr_name,
diff --git a/include/linux/key.h b/include/linux/key.h
index 66f705243985..7321ab8ef949 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -177,6 +177,7 @@ struct key {
 #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 */
 #define KEY_FLAG_ROOT_CAN_INVAL	11	/* set if key can be invalidated by root without permission */
+#define KEY_FLAG_KEEP		12	/* set if key should not be removed */
 
 	/* the key type and key description string
 	 * - the desc is used to match a key against search criteria
diff --git a/security/integrity/Kconfig b/security/integrity/Kconfig
index 73c457bf5a4a..21d756832b75 100644
--- a/security/integrity/Kconfig
+++ b/security/integrity/Kconfig
@@ -41,6 +41,17 @@ config INTEGRITY_ASYMMETRIC_KEYS
 	  This option enables digital signature verification using
 	  asymmetric keys.
 
+config INTEGRITY_TRUSTED_KEYRING
+	bool "Require all keys on the integrity keyrings be signed"
+	depends on 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 and
+	   .evm keyrings be signed by a key on the system trusted
+	   keyring.
+
 config INTEGRITY_AUDIT
 	bool "Enables integrity auditing support "
 	depends on AUDIT
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index 5be9ffbe90ba..8ef15118cc78 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -24,15 +24,22 @@
 static struct key *keyring[INTEGRITY_KEYRING_MAX];
 
 static const char *keyring_name[INTEGRITY_KEYRING_MAX] = {
+#ifndef CONFIG_INTEGRITY_TRUSTED_KEYRING
 	"_evm",
-	"_module",
-#ifndef CONFIG_IMA_TRUSTED_KEYRING
 	"_ima",
 #else
+	".evm",
 	".ima",
 #endif
+	"_module",
 };
 
+#ifdef CONFIG_INTEGRITY_TRUSTED_KEYRING
+static bool init_keyring __initdata = true;
+#else
+static bool init_keyring __initdata;
+#endif
+
 int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
 			    const char *digest, int digestlen)
 {
@@ -68,6 +75,9 @@ int __init integrity_init_keyring(const unsigned int id)
 	const struct cred *cred = current_cred();
 	int err = 0;
 
+	if (!init_keyring)
+		return 0;
+
 	keyring[id] = keyring_alloc(keyring_name[id], KUIDT_INIT(0),
 				    KGIDT_INIT(0), cred,
 				    ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
diff --git a/security/integrity/digsig_asymmetric.c b/security/integrity/digsig_asymmetric.c
index 4fec1816a2b3..5ade2a7517a6 100644
--- a/security/integrity/digsig_asymmetric.c
+++ b/security/integrity/digsig_asymmetric.c
@@ -17,6 +17,7 @@
 #include <linux/key-type.h>
 #include <crypto/public_key.h>
 #include <keys/asymmetric-type.h>
+#include <keys/system_keyring.h>
 
 #include "integrity.h"
 
@@ -32,9 +33,22 @@ static struct key *request_asymmetric_key(struct key *keyring, uint32_t keyid)
 
 	pr_debug("key search: \"%s\"\n", name);
 
+	key = get_ima_blacklist_keyring();
+	if (key) {
+		key_ref_t kref;
+
+		kref = keyring_search(make_key_ref(key, 1),
+				     &key_type_asymmetric, name);
+		if (!IS_ERR(kref)) {
+			pr_err("Key '%s' is in ima_blacklist_keyring\n", name);
+			return ERR_PTR(-EKEYREJECTED);
+		}
+	}
+
 	if (keyring) {
 		/* search in specific keyring */
 		key_ref_t kref;
+
 		kref = keyring_search(make_key_ref(keyring, 1),
 				      &key_type_asymmetric, name);
 		if (IS_ERR(kref))
diff --git a/security/integrity/evm/Kconfig b/security/integrity/evm/Kconfig
index bf19723cf117..e825e0ae78e7 100644
--- a/security/integrity/evm/Kconfig
+++ b/security/integrity/evm/Kconfig
@@ -42,3 +42,20 @@ config EVM_EXTRA_SMACK_XATTRS
 	  additional info to the calculation, requires existing EVM
 	  labeled file systems to be relabeled.
 
+config EVM_LOAD_X509
+	bool "Load an X509 certificate onto the '.evm' trusted keyring"
+	depends on EVM && INTEGRITY_TRUSTED_KEYRING
+	default n
+	help
+	   Load an X509 certificate onto the '.evm' trusted keyring.
+
+	   This option enables X509 certificate loading from the kernel
+	   onto the '.evm' trusted keyring.  A public key can be used to
+	   verify EVM integrity starting from the 'init' process.
+
+config EVM_X509_PATH
+	string "EVM X509 certificate path"
+	depends on EVM_LOAD_X509
+	default "/etc/keys/x509_evm.der"
+	help
+	   This option defines X509 certificate path.
diff --git a/security/integrity/evm/evm.h b/security/integrity/evm/evm.h
index 88bfe77efa1c..f5f12727771a 100644
--- a/security/integrity/evm/evm.h
+++ b/security/integrity/evm/evm.h
@@ -21,6 +21,9 @@
 
 #include "../integrity.h"
 
+#define EVM_INIT_HMAC	0x0001
+#define EVM_INIT_X509	0x0002
+
 extern int evm_initialized;
 extern char *evm_hmac;
 extern char *evm_hash;
diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c
index 461f8d891579..30b6b7d0429f 100644
--- a/security/integrity/evm/evm_crypto.c
+++ b/security/integrity/evm/evm_crypto.c
@@ -18,6 +18,7 @@
 #include <linux/module.h>
 #include <linux/crypto.h>
 #include <linux/xattr.h>
+#include <linux/evm.h>
 #include <keys/encrypted-type.h>
 #include <crypto/hash.h>
 #include "evm.h"
@@ -32,6 +33,44 @@ struct crypto_shash *hash_tfm;
 
 static DEFINE_MUTEX(mutex);
 
+#define EVM_SET_KEY_BUSY 0
+
+static unsigned long evm_set_key_flags;
+
+/**
+ * evm_set_key() - set EVM HMAC key from the kernel
+ * @key: pointer to a buffer with the key data
+ * @size: length of the key data
+ *
+ * This function allows setting the EVM HMAC key from the kernel
+ * without using the "encrypted" key subsystem keys. It can be used
+ * by the crypto HW kernel module which has its own way of managing
+ * keys.
+ *
+ * key length should be between 32 and 128 bytes long
+ */
+int evm_set_key(void *key, size_t keylen)
+{
+	int rc;
+
+	rc = -EBUSY;
+	if (test_and_set_bit(EVM_SET_KEY_BUSY, &evm_set_key_flags))
+		goto busy;
+	rc = -EINVAL;
+	if (keylen > MAX_KEY_SIZE)
+		goto inval;
+	memcpy(evmkey, key, keylen);
+	evm_initialized |= EVM_INIT_HMAC;
+	pr_info("key initialized\n");
+	return 0;
+inval:
+	clear_bit(EVM_SET_KEY_BUSY, &evm_set_key_flags);
+busy:
+	pr_err("key initialization failed\n");
+	return rc;
+}
+EXPORT_SYMBOL_GPL(evm_set_key);
+
 static struct shash_desc *init_desc(char type)
 {
 	long rc;
@@ -40,6 +79,10 @@ static struct shash_desc *init_desc(char type)
 	struct shash_desc *desc;
 
 	if (type == EVM_XATTR_HMAC) {
+		if (!(evm_initialized & EVM_INIT_HMAC)) {
+			pr_err("HMAC key is not set\n");
+			return ERR_PTR(-ENOKEY);
+		}
 		tfm = &hmac_tfm;
 		algo = evm_hmac;
 	} else {
@@ -240,7 +283,7 @@ int evm_init_key(void)
 {
 	struct key *evm_key;
 	struct encrypted_key_payload *ekp;
-	int rc = 0;
+	int rc;
 
 	evm_key = request_key(&key_type_encrypted, EVMKEY, NULL);
 	if (IS_ERR(evm_key))
@@ -248,12 +291,9 @@ int evm_init_key(void)
 
 	down_read(&evm_key->sem);
 	ekp = evm_key->payload.data[0];
-	if (ekp->decrypted_datalen > MAX_KEY_SIZE) {
-		rc = -EINVAL;
-		goto out;
-	}
-	memcpy(evmkey, ekp->decrypted_data, ekp->decrypted_datalen);
-out:
+
+	rc = evm_set_key(ekp->decrypted_data, ekp->decrypted_datalen);
+
 	/* burn the original key contents */
 	memset(ekp->decrypted_data, 0, ekp->decrypted_datalen);
 	up_read(&evm_key->sem);
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index 1334e02ae8f4..f7160253f17f 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -358,6 +358,15 @@ int evm_inode_removexattr(struct dentry *dentry, const char *xattr_name)
 	return evm_protect_xattr(dentry, xattr_name, NULL, 0);
 }
 
+static void evm_reset_status(struct inode *inode)
+{
+	struct integrity_iint_cache *iint;
+
+	iint = integrity_iint_find(inode);
+	if (iint)
+		iint->evm_status = INTEGRITY_UNKNOWN;
+}
+
 /**
  * evm_inode_post_setxattr - update 'security.evm' to reflect the changes
  * @dentry: pointer to the affected dentry
@@ -378,6 +387,8 @@ void evm_inode_post_setxattr(struct dentry *dentry, const char *xattr_name,
 				 && !posix_xattr_acl(xattr_name)))
 		return;
 
+	evm_reset_status(dentry->d_inode);
+
 	evm_update_evmxattr(dentry, xattr_name, xattr_value, xattr_value_len);
 }
 
@@ -396,6 +407,8 @@ void evm_inode_post_removexattr(struct dentry *dentry, const char *xattr_name)
 	if (!evm_initialized || !evm_protected_xattr(xattr_name))
 		return;
 
+	evm_reset_status(dentry->d_inode);
+
 	evm_update_evmxattr(dentry, xattr_name, NULL, 0);
 }
 
@@ -472,21 +485,34 @@ out:
 }
 EXPORT_SYMBOL_GPL(evm_inode_init_security);
 
+#ifdef CONFIG_EVM_LOAD_X509
+void __init evm_load_x509(void)
+{
+	int rc;
+
+	rc = integrity_load_x509(INTEGRITY_KEYRING_EVM, CONFIG_EVM_X509_PATH);
+	if (!rc)
+		evm_initialized |= EVM_INIT_X509;
+}
+#endif
+
 static int __init init_evm(void)
 {
 	int error;
 
 	evm_init_config();
 
+	error = integrity_init_keyring(INTEGRITY_KEYRING_EVM);
+	if (error)
+		return error;
+
 	error = evm_init_secfs();
 	if (error < 0) {
 		pr_info("Error registering secfs\n");
-		goto err;
+		return error;
 	}
 
 	return 0;
-err:
-	return error;
 }
 
 /*
diff --git a/security/integrity/evm/evm_secfs.c b/security/integrity/evm/evm_secfs.c
index cf12a04717d3..c8dccd54d501 100644
--- a/security/integrity/evm/evm_secfs.c
+++ b/security/integrity/evm/evm_secfs.c
@@ -62,9 +62,9 @@ static ssize_t evm_write_key(struct file *file, const char __user *buf,
 			     size_t count, loff_t *ppos)
 {
 	char temp[80];
-	int i, error;
+	int i;
 
-	if (!capable(CAP_SYS_ADMIN) || evm_initialized)
+	if (!capable(CAP_SYS_ADMIN) || (evm_initialized & EVM_INIT_HMAC))
 		return -EPERM;
 
 	if (count >= sizeof(temp) || count == 0)
@@ -78,12 +78,8 @@ static ssize_t evm_write_key(struct file *file, const char __user *buf,
 	if ((sscanf(temp, "%d", &i) != 1) || (i != 1))
 		return -EINVAL;
 
-	error = evm_init_key();
-	if (!error) {
-		evm_initialized = 1;
-		pr_info("initialized\n");
-	} else
-		pr_err("initialization failed\n");
+	evm_init_key();
+
 	return count;
 }
 
diff --git a/security/integrity/iint.c b/security/integrity/iint.c
index 3d2f5b45c8cb..2de9c820903f 100644
--- a/security/integrity/iint.c
+++ b/security/integrity/iint.c
@@ -254,4 +254,5 @@ out:
 void __init integrity_load_keys(void)
 {
 	ima_load_x509();
+	evm_load_x509();
 }
diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig
index df303346029b..e54a8a8dae94 100644
--- a/security/integrity/ima/Kconfig
+++ b/security/integrity/ima/Kconfig
@@ -107,6 +107,27 @@ config IMA_DEFAULT_HASH
 	default "sha512" if IMA_DEFAULT_HASH_SHA512
 	default "wp512" if IMA_DEFAULT_HASH_WP512
 
+config IMA_WRITE_POLICY
+	bool "Enable multiple writes to the IMA policy"
+	depends on IMA
+	default n
+	help
+	  IMA policy can now be updated multiple times.  The new rules get
+	  appended to the original policy.  Have in mind that the rules are
+	  scanned in FIFO order so be careful when you design and add new ones.
+
+	  If unsure, say N.
+
+config IMA_READ_POLICY
+	bool "Enable reading back the current IMA policy"
+	depends on IMA
+	default y if IMA_WRITE_POLICY
+	default n if !IMA_WRITE_POLICY
+	help
+	   It is often useful to be able to read back the IMA policy.  It is
+	   even more important after introducing CONFIG_IMA_WRITE_POLICY.
+	   This option allows the root user to see the current policy rules.
+
 config IMA_APPRAISE
 	bool "Appraise integrity measurements"
 	depends on IMA
@@ -123,14 +144,35 @@ config IMA_APPRAISE
 	  If unsure, say N.
 
 config IMA_TRUSTED_KEYRING
-	bool "Require all keys on the .ima keyring be signed"
+	bool "Require all keys on the .ima keyring be signed (deprecated)"
 	depends on IMA_APPRAISE && SYSTEM_TRUSTED_KEYRING
 	depends on INTEGRITY_ASYMMETRIC_KEYS
+	select INTEGRITY_TRUSTED_KEYRING
 	default y
 	help
 	   This option requires that all keys added to the .ima
 	   keyring be signed by a key on the system trusted keyring.
 
+	   This option is deprecated in favor of INTEGRITY_TRUSTED_KEYRING
+
+config IMA_MOK_KEYRING
+	bool "Create IMA machine owner keys (MOK) and blacklist keyrings"
+	depends on SYSTEM_TRUSTED_KEYRING
+	depends on IMA_TRUSTED_KEYRING
+	default n
+	help
+	   This option creates IMA MOK and blacklist keyrings.  IMA MOK is an
+	   intermediate keyring that sits between .system and .ima keyrings,
+	   effectively forming a simple CA hierarchy.  To successfully import a
+	   key into .ima_mok it must be signed by a key which CA is in .system
+	   keyring.  On turn any key that needs to go in .ima keyring must be
+	   signed by CA in either .system or .ima_mok keyrings. IMA MOK is empty
+	   at kernel boot.
+
+	   IMA blacklist keyring contains all revoked IMA keys.  It is consulted
+	   before any other keyring.  If the search is successful the requested
+	   operation is rejected and error is returned to the caller.
+
 config IMA_LOAD_X509
 	bool "Load X509 certificate onto the '.ima' trusted keyring"
 	depends on IMA_TRUSTED_KEYRING
diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile
index d79263d2fdbf..a8539f9e060f 100644
--- a/security/integrity/ima/Makefile
+++ b/security/integrity/ima/Makefile
@@ -8,3 +8,4 @@ obj-$(CONFIG_IMA) += ima.o
 ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \
 	 ima_policy.o ima_template.o ima_template_lib.o
 ima-$(CONFIG_IMA_APPRAISE) += ima_appraise.o
+obj-$(CONFIG_IMA_MOK_KEYRING) += ima_mok.o
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index e2a60c30df44..585af61ed399 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -166,6 +166,11 @@ void ima_update_policy(void);
 void ima_update_policy_flag(void);
 ssize_t ima_parse_add_rule(char *);
 void ima_delete_rules(void);
+int ima_check_policy(void);
+void *ima_policy_start(struct seq_file *m, loff_t *pos);
+void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos);
+void ima_policy_stop(struct seq_file *m, void *v);
+int ima_policy_show(struct seq_file *m, void *v);
 
 /* Appraise integrity measurements */
 #define IMA_APPRAISE_ENFORCE	0x01
@@ -250,17 +255,12 @@ static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
 {
 	return -EINVAL;
 }
-#endif /* CONFIG_IMA_LSM_RULES */
+#endif /* CONFIG_IMA_TRUSTED_KEYRING */
 
-#ifdef CONFIG_IMA_TRUSTED_KEYRING
-static inline int ima_init_keyring(const unsigned int id)
-{
-	return integrity_init_keyring(id);
-}
+#ifdef	CONFIG_IMA_READ_POLICY
+#define	POLICY_FILE_FLAGS	(S_IWUSR | S_IRUSR)
 #else
-static inline int ima_init_keyring(const unsigned int id)
-{
-	return 0;
-}
-#endif /* CONFIG_IMA_TRUSTED_KEYRING */
-#endif
+#define	POLICY_FILE_FLAGS	S_IWUSR
+#endif /* CONFIG_IMA_WRITE_POLICY */
+
+#endif /* __LINUX_IMA_H */
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index 816d175da79a..3caed6de610c 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -25,6 +25,8 @@
 
 #include "ima.h"
 
+static DEFINE_MUTEX(ima_write_mutex);
+
 static int valid_policy = 1;
 #define TMPBUFLEN 12
 static ssize_t ima_show_htable_value(char __user *buf, size_t count,
@@ -261,6 +263,11 @@ static ssize_t ima_write_policy(struct file *file, const char __user *buf,
 {
 	char *data = NULL;
 	ssize_t result;
+	int res;
+
+	res = mutex_lock_interruptible(&ima_write_mutex);
+	if (res)
+		return res;
 
 	if (datalen >= PAGE_SIZE)
 		datalen = PAGE_SIZE - 1;
@@ -286,6 +293,8 @@ out:
 	if (result < 0)
 		valid_policy = 0;
 	kfree(data);
+	mutex_unlock(&ima_write_mutex);
+
 	return result;
 }
 
@@ -302,14 +311,31 @@ enum ima_fs_flags {
 
 static unsigned long ima_fs_flags;
 
+#ifdef	CONFIG_IMA_READ_POLICY
+static const struct seq_operations ima_policy_seqops = {
+		.start = ima_policy_start,
+		.next = ima_policy_next,
+		.stop = ima_policy_stop,
+		.show = ima_policy_show,
+};
+#endif
+
 /*
  * ima_open_policy: sequentialize access to the policy file
  */
 static int ima_open_policy(struct inode *inode, struct file *filp)
 {
-	/* No point in being allowed to open it if you aren't going to write */
-	if (!(filp->f_flags & O_WRONLY))
+	if (!(filp->f_flags & O_WRONLY)) {
+#ifndef	CONFIG_IMA_READ_POLICY
 		return -EACCES;
+#else
+		if ((filp->f_flags & O_ACCMODE) != O_RDONLY)
+			return -EACCES;
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		return seq_open(filp, &ima_policy_seqops);
+#endif
+	}
 	if (test_and_set_bit(IMA_FS_BUSY, &ima_fs_flags))
 		return -EBUSY;
 	return 0;
@@ -326,6 +352,14 @@ static int ima_release_policy(struct inode *inode, struct file *file)
 {
 	const char *cause = valid_policy ? "completed" : "failed";
 
+	if ((file->f_flags & O_ACCMODE) == O_RDONLY)
+		return 0;
+
+	if (valid_policy && ima_check_policy() < 0) {
+		cause = "failed";
+		valid_policy = 0;
+	}
+
 	pr_info("IMA: policy update %s\n", cause);
 	integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, NULL,
 			    "policy_update", cause, !valid_policy, 0);
@@ -336,15 +370,21 @@ static int ima_release_policy(struct inode *inode, struct file *file)
 		clear_bit(IMA_FS_BUSY, &ima_fs_flags);
 		return 0;
 	}
+
 	ima_update_policy();
+#ifndef	CONFIG_IMA_WRITE_POLICY
 	securityfs_remove(ima_policy);
 	ima_policy = NULL;
+#else
+	clear_bit(IMA_FS_BUSY, &ima_fs_flags);
+#endif
 	return 0;
 }
 
 static const struct file_operations ima_measure_policy_ops = {
 	.open = ima_open_policy,
 	.write = ima_write_policy,
+	.read = seq_read,
 	.release = ima_release_policy,
 	.llseek = generic_file_llseek,
 };
@@ -382,8 +422,7 @@ int __init ima_fs_init(void)
 	if (IS_ERR(violations))
 		goto out;
 
-	ima_policy = securityfs_create_file("policy",
-					    S_IWUSR,
+	ima_policy = securityfs_create_file("policy", POLICY_FILE_FLAGS,
 					    ima_dir, NULL,
 					    &ima_measure_policy_ops);
 	if (IS_ERR(ima_policy))
diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
index e600cadd231c..bd79f254d204 100644
--- a/security/integrity/ima/ima_init.c
+++ b/security/integrity/ima/ima_init.c
@@ -116,7 +116,7 @@ int __init ima_init(void)
 	if (!ima_used_chip)
 		pr_info("No TPM chip found, activating TPM-bypass!\n");
 
-	rc = ima_init_keyring(INTEGRITY_KEYRING_IMA);
+	rc = integrity_init_keyring(INTEGRITY_KEYRING_IMA);
 	if (rc)
 		return rc;
 
diff --git a/security/integrity/ima/ima_mok.c b/security/integrity/ima/ima_mok.c
new file mode 100644
index 000000000000..676885e4320e
--- /dev/null
+++ b/security/integrity/ima/ima_mok.c
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2015 Juniper Networks, Inc.
+ *
+ * Author:
+ * Petko Manolov <petko.manolov@konsulko.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ *
+ */
+
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/cred.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <keys/asymmetric-type.h>
+
+
+struct key *ima_mok_keyring;
+struct key *ima_blacklist_keyring;
+
+/*
+ * Allocate the IMA MOK and blacklist keyrings
+ */
+__init int ima_mok_init(void)
+{
+	pr_notice("Allocating IMA MOK and blacklist keyrings.\n");
+
+	ima_mok_keyring = keyring_alloc(".ima_mok",
+			      KUIDT_INIT(0), KGIDT_INIT(0), current_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);
+
+	ima_blacklist_keyring = keyring_alloc(".ima_blacklist",
+				KUIDT_INIT(0), KGIDT_INIT(0), current_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(ima_mok_keyring) || IS_ERR(ima_blacklist_keyring))
+		panic("Can't allocate IMA MOK or blacklist keyrings.");
+	set_bit(KEY_FLAG_TRUSTED_ONLY, &ima_mok_keyring->flags);
+
+	set_bit(KEY_FLAG_TRUSTED_ONLY, &ima_blacklist_keyring->flags);
+	set_bit(KEY_FLAG_KEEP, &ima_blacklist_keyring->flags);
+	return 0;
+}
+device_initcall(ima_mok_init);
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 3997e206f82d..0a3b781f18e5 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -16,7 +16,9 @@
 #include <linux/magic.h>
 #include <linux/parser.h>
 #include <linux/slab.h>
+#include <linux/rculist.h>
 #include <linux/genhd.h>
+#include <linux/seq_file.h>
 
 #include "ima.h"
 
@@ -38,6 +40,7 @@
 #define AUDIT		0x0040
 
 int ima_policy_flag;
+static int temp_ima_appraise;
 
 #define MAX_LSM_RULES 6
 enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE,
@@ -135,11 +138,11 @@ static struct ima_rule_entry default_appraise_rules[] = {
 
 static LIST_HEAD(ima_default_rules);
 static LIST_HEAD(ima_policy_rules);
+static LIST_HEAD(ima_temp_rules);
 static struct list_head *ima_rules;
 
-static DEFINE_MUTEX(ima_rules_mutex);
-
 static int ima_policy __initdata;
+
 static int __init default_measure_policy_setup(char *str)
 {
 	if (ima_policy)
@@ -171,21 +174,18 @@ static int __init default_appraise_policy_setup(char *str)
 __setup("ima_appraise_tcb", default_appraise_policy_setup);
 
 /*
- * Although the IMA policy does not change, the LSM policy can be
- * reloaded, leaving the IMA LSM based rules referring to the old,
- * stale LSM policy.
- *
- * Update the IMA LSM based rules to reflect the reloaded LSM policy.
- * We assume the rules still exist; and BUG_ON() if they don't.
+ * The LSM policy can be reloaded, leaving the IMA LSM based rules referring
+ * to the old, stale LSM policy.  Update the IMA LSM based rules to reflect
+ * the reloaded LSM policy.  We assume the rules still exist; and BUG_ON() if
+ * they don't.
  */
 static void ima_lsm_update_rules(void)
 {
-	struct ima_rule_entry *entry, *tmp;
+	struct ima_rule_entry *entry;
 	int result;
 	int i;
 
-	mutex_lock(&ima_rules_mutex);
-	list_for_each_entry_safe(entry, tmp, &ima_policy_rules, list) {
+	list_for_each_entry(entry, &ima_policy_rules, list) {
 		for (i = 0; i < MAX_LSM_RULES; i++) {
 			if (!entry->lsm[i].rule)
 				continue;
@@ -196,7 +196,6 @@ static void ima_lsm_update_rules(void)
 			BUG_ON(!entry->lsm[i].rule);
 		}
 	}
-	mutex_unlock(&ima_rules_mutex);
 }
 
 /**
@@ -319,9 +318,9 @@ static int get_subaction(struct ima_rule_entry *rule, int func)
  * Measure decision based on func/mask/fsmagic and LSM(subj/obj/type)
  * conditions.
  *
- * (There is no need for locking when walking the policy list,
- * as elements in the list are never deleted, nor does the list
- * change.)
+ * Since the IMA policy may be updated multiple times we need to lock the
+ * list when walking it.  Reads are many orders of magnitude more numerous
+ * than writes so ima_match_policy() is classical RCU candidate.
  */
 int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,
 		     int flags)
@@ -329,7 +328,8 @@ int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,
 	struct ima_rule_entry *entry;
 	int action = 0, actmask = flags | (flags << 1);
 
-	list_for_each_entry(entry, ima_rules, list) {
+	rcu_read_lock();
+	list_for_each_entry_rcu(entry, ima_rules, list) {
 
 		if (!(entry->action & actmask))
 			continue;
@@ -351,6 +351,7 @@ int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,
 		if (!actmask)
 			break;
 	}
+	rcu_read_unlock();
 
 	return action;
 }
@@ -365,12 +366,12 @@ void ima_update_policy_flag(void)
 {
 	struct ima_rule_entry *entry;
 
-	ima_policy_flag = 0;
 	list_for_each_entry(entry, ima_rules, list) {
 		if (entry->action & IMA_DO_MASK)
 			ima_policy_flag |= entry->action;
 	}
 
+	ima_appraise |= temp_ima_appraise;
 	if (!ima_appraise)
 		ima_policy_flag &= ~IMA_APPRAISE;
 }
@@ -415,16 +416,48 @@ void __init ima_init_policy(void)
 	ima_rules = &ima_default_rules;
 }
 
+/* Make sure we have a valid policy, at least containing some rules. */
+int ima_check_policy()
+{
+	if (list_empty(&ima_temp_rules))
+		return -EINVAL;
+	return 0;
+}
+
 /**
  * ima_update_policy - update default_rules with new measure rules
  *
  * Called on file .release to update the default rules with a complete new
- * policy.  Once updated, the policy is locked, no additional rules can be
- * added to the policy.
+ * policy.  What we do here is to splice ima_policy_rules and ima_temp_rules so
+ * they make a queue.  The policy may be updated multiple times and this is the
+ * RCU updater.
+ *
+ * Policy rules are never deleted so ima_policy_flag gets zeroed only once when
+ * we switch from the default policy to user defined.
  */
 void ima_update_policy(void)
 {
-	ima_rules = &ima_policy_rules;
+	struct list_head *first, *last, *policy;
+
+	/* append current policy with the new rules */
+	first = (&ima_temp_rules)->next;
+	last = (&ima_temp_rules)->prev;
+	policy = &ima_policy_rules;
+
+	synchronize_rcu();
+
+	last->next = policy;
+	rcu_assign_pointer(list_next_rcu(policy->prev), first);
+	first->prev = policy->prev;
+	policy->prev = last;
+
+	/* prepare for the next policy rules addition */
+	INIT_LIST_HEAD(&ima_temp_rules);
+
+	if (ima_rules != policy) {
+		ima_policy_flag = 0;
+		ima_rules = policy;
+	}
 	ima_update_policy_flag();
 }
 
@@ -436,8 +469,8 @@ enum {
 	Opt_obj_user, Opt_obj_role, Opt_obj_type,
 	Opt_subj_user, Opt_subj_role, Opt_subj_type,
 	Opt_func, Opt_mask, Opt_fsmagic,
-	Opt_uid, Opt_euid, Opt_fowner,
-	Opt_appraise_type, Opt_fsuuid, Opt_permit_directio
+	Opt_fsuuid, Opt_uid, Opt_euid, Opt_fowner,
+	Opt_appraise_type, Opt_permit_directio
 };
 
 static match_table_t policy_tokens = {
@@ -734,9 +767,9 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 	if (!result && (entry->action == UNKNOWN))
 		result = -EINVAL;
 	else if (entry->func == MODULE_CHECK)
-		ima_appraise |= IMA_APPRAISE_MODULES;
+		temp_ima_appraise |= IMA_APPRAISE_MODULES;
 	else if (entry->func == FIRMWARE_CHECK)
-		ima_appraise |= IMA_APPRAISE_FIRMWARE;
+		temp_ima_appraise |= IMA_APPRAISE_FIRMWARE;
 	audit_log_format(ab, "res=%d", !result);
 	audit_log_end(ab);
 	return result;
@@ -746,7 +779,7 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
  * ima_parse_add_rule - add a rule to ima_policy_rules
  * @rule - ima measurement policy rule
  *
- * Uses a mutex to protect the policy list from multiple concurrent writers.
+ * Avoid locking by allowing just one writer at a time in ima_write_policy()
  * Returns the length of the rule parsed, an error code on failure
  */
 ssize_t ima_parse_add_rule(char *rule)
@@ -782,26 +815,230 @@ ssize_t ima_parse_add_rule(char *rule)
 		return result;
 	}
 
-	mutex_lock(&ima_rules_mutex);
-	list_add_tail(&entry->list, &ima_policy_rules);
-	mutex_unlock(&ima_rules_mutex);
+	list_add_tail(&entry->list, &ima_temp_rules);
 
 	return len;
 }
 
-/* ima_delete_rules called to cleanup invalid policy */
+/**
+ * ima_delete_rules() called to cleanup invalid in-flight policy.
+ * We don't need locking as we operate on the temp list, which is
+ * different from the active one.  There is also only one user of
+ * ima_delete_rules() at a time.
+ */
 void ima_delete_rules(void)
 {
 	struct ima_rule_entry *entry, *tmp;
 	int i;
 
-	mutex_lock(&ima_rules_mutex);
-	list_for_each_entry_safe(entry, tmp, &ima_policy_rules, list) {
+	temp_ima_appraise = 0;
+	list_for_each_entry_safe(entry, tmp, &ima_temp_rules, list) {
 		for (i = 0; i < MAX_LSM_RULES; i++)
 			kfree(entry->lsm[i].args_p);
 
 		list_del(&entry->list);
 		kfree(entry);
 	}
-	mutex_unlock(&ima_rules_mutex);
 }
+
+#ifdef	CONFIG_IMA_READ_POLICY
+enum {
+	mask_exec = 0, mask_write, mask_read, mask_append
+};
+
+static char *mask_tokens[] = {
+	"MAY_EXEC",
+	"MAY_WRITE",
+	"MAY_READ",
+	"MAY_APPEND"
+};
+
+enum {
+	func_file = 0, func_mmap, func_bprm,
+	func_module, func_firmware, func_post
+};
+
+static char *func_tokens[] = {
+	"FILE_CHECK",
+	"MMAP_CHECK",
+	"BPRM_CHECK",
+	"MODULE_CHECK",
+	"FIRMWARE_CHECK",
+	"POST_SETATTR"
+};
+
+void *ima_policy_start(struct seq_file *m, loff_t *pos)
+{
+	loff_t l = *pos;
+	struct ima_rule_entry *entry;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(entry, ima_rules, list) {
+		if (!l--) {
+			rcu_read_unlock();
+			return entry;
+		}
+	}
+	rcu_read_unlock();
+	return NULL;
+}
+
+void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	struct ima_rule_entry *entry = v;
+
+	rcu_read_lock();
+	entry = list_entry_rcu(entry->list.next, struct ima_rule_entry, list);
+	rcu_read_unlock();
+	(*pos)++;
+
+	return (&entry->list == ima_rules) ? NULL : entry;
+}
+
+void ima_policy_stop(struct seq_file *m, void *v)
+{
+}
+
+#define pt(token)	policy_tokens[token + Opt_err].pattern
+#define mt(token)	mask_tokens[token]
+#define ft(token)	func_tokens[token]
+
+int ima_policy_show(struct seq_file *m, void *v)
+{
+	struct ima_rule_entry *entry = v;
+	int i = 0;
+	char tbuf[64] = {0,};
+
+	rcu_read_lock();
+
+	if (entry->action & MEASURE)
+		seq_puts(m, pt(Opt_measure));
+	if (entry->action & DONT_MEASURE)
+		seq_puts(m, pt(Opt_dont_measure));
+	if (entry->action & APPRAISE)
+		seq_puts(m, pt(Opt_appraise));
+	if (entry->action & DONT_APPRAISE)
+		seq_puts(m, pt(Opt_dont_appraise));
+	if (entry->action & AUDIT)
+		seq_puts(m, pt(Opt_audit));
+
+	seq_puts(m, " ");
+
+	if (entry->flags & IMA_FUNC) {
+		switch (entry->func) {
+		case FILE_CHECK:
+			seq_printf(m, pt(Opt_func), ft(func_file));
+			break;
+		case MMAP_CHECK:
+			seq_printf(m, pt(Opt_func), ft(func_mmap));
+			break;
+		case BPRM_CHECK:
+			seq_printf(m, pt(Opt_func), ft(func_bprm));
+			break;
+		case MODULE_CHECK:
+			seq_printf(m, pt(Opt_func), ft(func_module));
+			break;
+		case FIRMWARE_CHECK:
+			seq_printf(m, pt(Opt_func), ft(func_firmware));
+			break;
+		case POST_SETATTR:
+			seq_printf(m, pt(Opt_func), ft(func_post));
+			break;
+		default:
+			snprintf(tbuf, sizeof(tbuf), "%d", entry->func);
+			seq_printf(m, pt(Opt_func), tbuf);
+			break;
+		}
+		seq_puts(m, " ");
+	}
+
+	if (entry->flags & IMA_MASK) {
+		if (entry->mask & MAY_EXEC)
+			seq_printf(m, pt(Opt_mask), mt(mask_exec));
+		if (entry->mask & MAY_WRITE)
+			seq_printf(m, pt(Opt_mask), mt(mask_write));
+		if (entry->mask & MAY_READ)
+			seq_printf(m, pt(Opt_mask), mt(mask_read));
+		if (entry->mask & MAY_APPEND)
+			seq_printf(m, pt(Opt_mask), mt(mask_append));
+		seq_puts(m, " ");
+	}
+
+	if (entry->flags & IMA_FSMAGIC) {
+		snprintf(tbuf, sizeof(tbuf), "0x%lx", entry->fsmagic);
+		seq_printf(m, pt(Opt_fsmagic), tbuf);
+		seq_puts(m, " ");
+	}
+
+	if (entry->flags & IMA_FSUUID) {
+		seq_puts(m, "fsuuid=");
+		for (i = 0; i < ARRAY_SIZE(entry->fsuuid); ++i) {
+			switch (i) {
+			case 4:
+			case 6:
+			case 8:
+			case 10:
+				seq_puts(m, "-");
+			}
+			seq_printf(m, "%x", entry->fsuuid[i]);
+		}
+		seq_puts(m, " ");
+	}
+
+	if (entry->flags & IMA_UID) {
+		snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->uid));
+		seq_printf(m, pt(Opt_uid), tbuf);
+		seq_puts(m, " ");
+	}
+
+	if (entry->flags & IMA_EUID) {
+		snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->uid));
+		seq_printf(m, pt(Opt_euid), tbuf);
+		seq_puts(m, " ");
+	}
+
+	if (entry->flags & IMA_FOWNER) {
+		snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->fowner));
+		seq_printf(m, pt(Opt_fowner), tbuf);
+		seq_puts(m, " ");
+	}
+
+	for (i = 0; i < MAX_LSM_RULES; i++) {
+		if (entry->lsm[i].rule) {
+			switch (i) {
+			case LSM_OBJ_USER:
+				seq_printf(m, pt(Opt_obj_user),
+					   (char *)entry->lsm[i].args_p);
+				break;
+			case LSM_OBJ_ROLE:
+				seq_printf(m, pt(Opt_obj_role),
+					   (char *)entry->lsm[i].args_p);
+				break;
+			case LSM_OBJ_TYPE:
+				seq_printf(m, pt(Opt_obj_type),
+					   (char *)entry->lsm[i].args_p);
+				break;
+			case LSM_SUBJ_USER:
+				seq_printf(m, pt(Opt_subj_user),
+					   (char *)entry->lsm[i].args_p);
+				break;
+			case LSM_SUBJ_ROLE:
+				seq_printf(m, pt(Opt_subj_role),
+					   (char *)entry->lsm[i].args_p);
+				break;
+			case LSM_SUBJ_TYPE:
+				seq_printf(m, pt(Opt_subj_type),
+					   (char *)entry->lsm[i].args_p);
+				break;
+			}
+		}
+	}
+	if (entry->flags & IMA_DIGSIG_REQUIRED)
+		seq_puts(m, "appraise_type=imasig ");
+	if (entry->flags & IMA_PERMIT_DIRECTIO)
+		seq_puts(m, "permit_directio ");
+	rcu_read_unlock();
+	seq_puts(m, "\n");
+	return 0;
+}
+#endif	/* CONFIG_IMA_READ_POLICY */
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index 9c6168709d3b..5efe2ecc538d 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -125,8 +125,8 @@ int integrity_kernel_read(struct file *file, loff_t offset,
 int __init integrity_read_file(const char *path, char **data);
 
 #define INTEGRITY_KEYRING_EVM		0
-#define INTEGRITY_KEYRING_MODULE	1
-#define INTEGRITY_KEYRING_IMA		2
+#define INTEGRITY_KEYRING_IMA		1
+#define INTEGRITY_KEYRING_MODULE	2
 #define INTEGRITY_KEYRING_MAX		3
 
 #ifdef CONFIG_INTEGRITY_SIGNATURE
@@ -149,7 +149,6 @@ static inline int integrity_init_keyring(const unsigned int id)
 {
 	return 0;
 }
-
 #endif /* CONFIG_INTEGRITY_SIGNATURE */
 
 #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
@@ -171,6 +170,14 @@ static inline void ima_load_x509(void)
 }
 #endif
 
+#ifdef CONFIG_EVM_LOAD_X509
+void __init evm_load_x509(void);
+#else
+static inline void evm_load_x509(void)
+{
+}
+#endif
+
 #ifdef CONFIG_INTEGRITY_AUDIT
 /* declarations */
 void integrity_audit_msg(int audit_msgno, struct inode *inode,
diff --git a/security/keys/key.c b/security/keys/key.c
index ab7997ded725..09ef276c4bdc 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -429,8 +429,12 @@ static int __key_instantiate_and_link(struct key *key,
 				awaken = 1;
 
 			/* and link it into the destination keyring */
-			if (keyring)
+			if (keyring) {
+				if (test_bit(KEY_FLAG_KEEP, &keyring->flags))
+					set_bit(KEY_FLAG_KEEP, &key->flags);
+
 				__key_link(key, _edit);
+			}
 
 			/* disable the authorisation key */
 			if (authkey)
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index fb111eafcb89..e83ec6b9eb9d 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -358,11 +358,14 @@ error:
  * and any links to the key will be automatically garbage collected after a
  * certain amount of time (/proc/sys/kernel/keys/gc_delay).
  *
+ * Keys with KEY_FLAG_KEEP set should not be revoked.
+ *
  * If successful, 0 is returned.
  */
 long keyctl_revoke_key(key_serial_t id)
 {
 	key_ref_t key_ref;
+	struct key *key;
 	long ret;
 
 	key_ref = lookup_user_key(id, 0, KEY_NEED_WRITE);
@@ -377,8 +380,13 @@ long keyctl_revoke_key(key_serial_t id)
 		}
 	}
 
-	key_revoke(key_ref_to_ptr(key_ref));
-	ret = 0;
+	key = key_ref_to_ptr(key_ref);
+	if (test_bit(KEY_FLAG_KEEP, &key->flags))
+		return -EPERM;
+	else {
+		key_revoke(key);
+		ret = 0;
+	}
 
 	key_ref_put(key_ref);
 error:
@@ -392,11 +400,14 @@ error:
  * The key and any links to the key will be automatically garbage collected
  * immediately.
  *
+ * Keys with KEY_FLAG_KEEP set should not be invalidated.
+ *
  * If successful, 0 is returned.
  */
 long keyctl_invalidate_key(key_serial_t id)
 {
 	key_ref_t key_ref;
+	struct key *key;
 	long ret;
 
 	kenter("%d", id);
@@ -420,8 +431,13 @@ long keyctl_invalidate_key(key_serial_t id)
 	}
 
 invalidate:
-	key_invalidate(key_ref_to_ptr(key_ref));
-	ret = 0;
+	key = key_ref_to_ptr(key_ref);
+	if (test_bit(KEY_FLAG_KEEP, &key->flags))
+		ret = -EPERM;
+	else {
+		key_invalidate(key);
+		ret = 0;
+	}
 error_put:
 	key_ref_put(key_ref);
 error:
@@ -433,12 +449,13 @@ error:
  * Clear the specified keyring, creating an empty process keyring if one of the
  * special keyring IDs is used.
  *
- * The keyring must grant the caller Write permission for this to work.  If
- * successful, 0 will be returned.
+ * The keyring must grant the caller Write permission and not have
+ * KEY_FLAG_KEEP set for this to work.  If successful, 0 will be returned.
  */
 long keyctl_keyring_clear(key_serial_t ringid)
 {
 	key_ref_t keyring_ref;
+	struct key *keyring;
 	long ret;
 
 	keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE);
@@ -460,7 +477,11 @@ long keyctl_keyring_clear(key_serial_t ringid)
 	}
 
 clear:
-	ret = keyring_clear(key_ref_to_ptr(keyring_ref));
+	keyring = key_ref_to_ptr(keyring_ref);
+	if (test_bit(KEY_FLAG_KEEP, &keyring->flags))
+		ret = -EPERM;
+	else
+		ret = keyring_clear(keyring);
 error_put:
 	key_ref_put(keyring_ref);
 error:
@@ -511,11 +532,14 @@ error:
  * itself need not grant the caller anything.  If the last link to a key is
  * removed then that key will be scheduled for destruction.
  *
+ * Keys or keyrings with KEY_FLAG_KEEP set should not be unlinked.
+ *
  * If successful, 0 will be returned.
  */
 long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid)
 {
 	key_ref_t keyring_ref, key_ref;
+	struct key *keyring, *key;
 	long ret;
 
 	keyring_ref = lookup_user_key(ringid, 0, KEY_NEED_WRITE);
@@ -530,7 +554,13 @@ long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid)
 		goto error2;
 	}
 
-	ret = key_unlink(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref));
+	keyring = key_ref_to_ptr(keyring_ref);
+	key = key_ref_to_ptr(key_ref);
+	if (test_bit(KEY_FLAG_KEEP, &keyring->flags) &&
+	    test_bit(KEY_FLAG_KEEP, &key->flags))
+		ret = -EPERM;
+	else
+		ret = key_unlink(keyring, key);
 
 	key_ref_put(key_ref);
 error2:
@@ -1289,6 +1319,8 @@ error:
  * the current time.  The key and any links to the key will be automatically
  * garbage collected after the timeout expires.
  *
+ * Keys with KEY_FLAG_KEEP set should not be timed out.
+ *
  * If successful, 0 is returned.
  */
 long keyctl_set_timeout(key_serial_t id, unsigned timeout)
@@ -1320,10 +1352,14 @@ long keyctl_set_timeout(key_serial_t id, unsigned timeout)
 
 okay:
 	key = key_ref_to_ptr(key_ref);
-	key_set_timeout(key, timeout);
+	if (test_bit(KEY_FLAG_KEEP, &key->flags))
+		ret = -EPERM;
+	else {
+		key_set_timeout(key, timeout);
+		ret = 0;
+	}
 	key_put(key);
 
-	ret = 0;
 error:
 	return ret;
 }