Merge tag 'keys-next-20160505' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs into next

19 files changed, 516 insertions, 112 deletions

diff --git a/security/integrity/Kconfig b/security/integrity/Kconfig
index 979be65..da95658 100644
--- a/security/integrity/Kconfig
+++ b/security/integrity/Kconfig
@@ -35,7 +35,6 @@ config INTEGRITY_ASYMMETRIC_KEYS
 	default n
         select ASYMMETRIC_KEY_TYPE
         select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
-        select PUBLIC_KEY_ALGO_RSA
         select CRYPTO_RSA
         select X509_CERTIFICATE_PARSER
 	help
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index 8ef1511..4304372 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -18,6 +18,8 @@
 #include <linux/cred.h>
 #include <linux/key-type.h>
 #include <linux/digsig.h>
+#include <crypto/public_key.h>
+#include <keys/system_keyring.h>
 
 #include "integrity.h"
 
@@ -40,6 +42,12 @@ static bool init_keyring __initdata = true;
 static bool init_keyring __initdata;
 #endif
 
+#ifdef CONFIG_IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY
+#define restrict_link_to_ima restrict_link_by_builtin_and_secondary_trusted
+#else
+#define restrict_link_to_ima restrict_link_by_builtin_trusted
+#endif
+
 int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
 			    const char *digest, int digestlen)
 {
@@ -83,10 +91,9 @@ int __init integrity_init_keyring(const unsigned int id)
 				    ((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 {
+				    KEY_ALLOC_NOT_IN_QUOTA,
+				    restrict_link_to_ima, NULL);
+	if (IS_ERR(keyring[id])) {
 		err = PTR_ERR(keyring[id]);
 		pr_info("Can't allocate %s keyring (%d)\n",
 			keyring_name[id], err);
diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig
index e54a8a8..5487827 100644
--- a/security/integrity/ima/Kconfig
+++ b/security/integrity/ima/Kconfig
@@ -155,23 +155,33 @@ config IMA_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"
+config IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY
+	bool "Permit keys validly signed by a built-in or secondary CA cert (EXPERIMENTAL)"
+	depends on SYSTEM_TRUSTED_KEYRING
+	depends on SECONDARY_TRUSTED_KEYRING
+	depends on INTEGRITY_ASYMMETRIC_KEYS
+	select INTEGRITY_TRUSTED_KEYRING
+	default n
+	help
+	  Keys may be added to the IMA or IMA blacklist keyrings, if the
+	  key is validly signed by a CA cert in the system built-in or
+	  secondary trusted keyrings.
+
+	  Intermediate keys between those the kernel has compiled in and the
+	  IMA keys to be added may be added to the system secondary keyring,
+	  provided they are validly signed by a key already resident in the
+	  built-in or secondary trusted keyrings.
+
+config IMA_BLACKLIST_KEYRING
+	bool "Create IMA machine owner blacklist keyrings (EXPERIMENTAL)"
 	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.
+	   This option creates an IMA blacklist keyring, which contains all
+	   revoked IMA keys.  It is consulted before any other keyring.  If
+	   the search is successful the requested operation is rejected and
+	   an error is returned to the caller.
 
 config IMA_LOAD_X509
 	bool "Load X509 certificate onto the '.ima' trusted keyring"
diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile
index a8539f9..9aeaeda 100644
--- a/security/integrity/ima/Makefile
+++ b/security/integrity/ima/Makefile
@@ -8,4 +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-$(CONFIG_IMA_MOK_KEYRING) += ima_mok.o
+obj-$(CONFIG_IMA_BLACKLIST_KEYRING) += ima_mok.o
diff --git a/security/integrity/ima/ima_mok.c b/security/integrity/ima/ima_mok.c
index 676885e..74a27995 100644
--- a/security/integrity/ima/ima_mok.c
+++ b/security/integrity/ima/ima_mok.c
@@ -17,38 +17,29 @@
 #include <linux/cred.h>
 #include <linux/err.h>
 #include <linux/init.h>
-#include <keys/asymmetric-type.h>
+#include <keys/system_keyring.h>
 
 
-struct key *ima_mok_keyring;
 struct key *ima_blacklist_keyring;
 
 /*
- * Allocate the IMA MOK and blacklist keyrings
+ * Allocate the IMA blacklist keyring
  */
 __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);
+	pr_notice("Allocating IMA blacklist keyring.\n");
 
 	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);
+				KEY_ALLOC_NOT_IN_QUOTA,
+				restrict_link_by_builtin_trusted, 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);
+	if (IS_ERR(ima_blacklist_keyring))
+		panic("Can't allocate IMA blacklist keyring.");
 
-	set_bit(KEY_FLAG_TRUSTED_ONLY, &ima_blacklist_keyring->flags);
 	set_bit(KEY_FLAG_KEEP, &ima_blacklist_keyring->flags);
 	return 0;
 }
diff --git a/security/keys/Kconfig b/security/keys/Kconfig
index fe4d74e..f826e87 100644
--- a/security/keys/Kconfig
+++ b/security/keys/Kconfig
@@ -41,6 +41,10 @@ config BIG_KEYS
 	bool "Large payload keys"
 	depends on KEYS
 	depends on TMPFS
+	select CRYPTO
+	select CRYPTO_AES
+	select CRYPTO_ECB
+	select CRYPTO_RNG
 	help
 	  This option provides support for holding large keys within the kernel
 	  (for example Kerberos ticket caches).  The data may be stored out to
@@ -81,3 +85,14 @@ config ENCRYPTED_KEYS
 	  Userspace only ever sees/stores encrypted blobs.
 
 	  If you are unsure as to whether this is required, answer N.
+
+config KEY_DH_OPERATIONS
+       bool "Diffie-Hellman operations on retained keys"
+       depends on KEYS
+       select MPILIB
+       help
+	 This option provides support for calculating Diffie-Hellman
+	 public keys and shared secrets using values stored as keys
+	 in the kernel.
+
+	 If you are unsure as to whether this is required, answer N.
diff --git a/security/keys/Makefile b/security/keys/Makefile
index dfb3a7b..1fd4a16 100644
--- a/security/keys/Makefile
+++ b/security/keys/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_KEYS_COMPAT) += compat.o
 obj-$(CONFIG_PROC_FS) += proc.o
 obj-$(CONFIG_SYSCTL) += sysctl.o
 obj-$(CONFIG_PERSISTENT_KEYRINGS) += persistent.o
+obj-$(CONFIG_KEY_DH_OPERATIONS) += dh.o
 
 #
 # Key types
diff --git a/security/keys/big_key.c b/security/keys/big_key.c
index c721e39..9e443fc 100644
--- a/security/keys/big_key.c
+++ b/security/keys/big_key.c
@@ -14,8 +14,10 @@
 #include <linux/file.h>
 #include <linux/shmem_fs.h>
 #include <linux/err.h>
+#include <linux/scatterlist.h>
 #include <keys/user-type.h>
 #include <keys/big_key-type.h>
+#include <crypto/rng.h>
 
 /*
  * Layout of key payload words.
@@ -28,6 +30,14 @@ enum {
 };
 
 /*
+ * Crypto operation with big_key data
+ */
+enum big_key_op {
+	BIG_KEY_ENC,
+	BIG_KEY_DEC,
+};
+
+/*
  * If the data is under this limit, there's no point creating a shm file to
  * hold it as the permanently resident metadata for the shmem fs will be at
  * least as large as the data.
@@ -35,6 +45,11 @@ enum {
 #define BIG_KEY_FILE_THRESHOLD (sizeof(struct inode) + sizeof(struct dentry))
 
 /*
+ * Key size for big_key data encryption
+ */
+#define ENC_KEY_SIZE	16
+
+/*
  * big_key defined keys take an arbitrary string as the description and an
  * arbitrary blob of data as the payload
  */
@@ -50,12 +65,62 @@ struct key_type key_type_big_key = {
 };
 
 /*
+ * Crypto names for big_key data encryption
+ */
+static const char big_key_rng_name[] = "stdrng";
+static const char big_key_alg_name[] = "ecb(aes)";
+
+/*
+ * Crypto algorithms for big_key data encryption
+ */
+static struct crypto_rng *big_key_rng;
+static struct crypto_blkcipher *big_key_blkcipher;
+
+/*
+ * Generate random key to encrypt big_key data
+ */
+static inline int big_key_gen_enckey(u8 *key)
+{
+	return crypto_rng_get_bytes(big_key_rng, key, ENC_KEY_SIZE);
+}
+
+/*
+ * Encrypt/decrypt big_key data
+ */
+static int big_key_crypt(enum big_key_op op, u8 *data, size_t datalen, u8 *key)
+{
+	int ret = -EINVAL;
+	struct scatterlist sgio;
+	struct blkcipher_desc desc;
+
+	if (crypto_blkcipher_setkey(big_key_blkcipher, key, ENC_KEY_SIZE)) {
+		ret = -EAGAIN;
+		goto error;
+	}
+
+	desc.flags = 0;
+	desc.tfm = big_key_blkcipher;
+
+	sg_init_one(&sgio, data, datalen);
+
+	if (op == BIG_KEY_ENC)
+		ret = crypto_blkcipher_encrypt(&desc, &sgio, &sgio, datalen);
+	else
+		ret = crypto_blkcipher_decrypt(&desc, &sgio, &sgio, datalen);
+
+error:
+	return ret;
+}
+
+/*
  * Preparse a big key
  */
 int big_key_preparse(struct key_preparsed_payload *prep)
 {
 	struct path *path = (struct path *)&prep->payload.data[big_key_path];
 	struct file *file;
+	u8 *enckey;
+	u8 *data = NULL;
 	ssize_t written;
 	size_t datalen = prep->datalen;
 	int ret;
@@ -73,16 +138,43 @@ int big_key_preparse(struct key_preparsed_payload *prep)
 		/* Create a shmem file to store the data in.  This will permit the data
 		 * to be swapped out if needed.
 		 *
-		 * TODO: Encrypt the stored data with a temporary key.
+		 * File content is stored encrypted with randomly generated key.
 		 */
-		file = shmem_kernel_file_setup("", datalen, 0);
+		size_t enclen = ALIGN(datalen, crypto_blkcipher_blocksize(big_key_blkcipher));
+
+		/* prepare aligned data to encrypt */
+		data = kmalloc(enclen, GFP_KERNEL);
+		if (!data)
+			return -ENOMEM;
+
+		memcpy(data, prep->data, datalen);
+		memset(data + datalen, 0x00, enclen - datalen);
+
+		/* generate random key */
+		enckey = kmalloc(ENC_KEY_SIZE, GFP_KERNEL);
+		if (!enckey) {
+			ret = -ENOMEM;
+			goto error;
+		}
+
+		ret = big_key_gen_enckey(enckey);
+		if (ret)
+			goto err_enckey;
+
+		/* encrypt aligned data */
+		ret = big_key_crypt(BIG_KEY_ENC, data, enclen, enckey);
+		if (ret)
+			goto err_enckey;
+
+		/* save aligned data to file */
+		file = shmem_kernel_file_setup("", enclen, 0);
 		if (IS_ERR(file)) {
 			ret = PTR_ERR(file);
-			goto error;
+			goto err_enckey;
 		}
 
-		written = kernel_write(file, prep->data, prep->datalen, 0);
-		if (written != datalen) {
+		written = kernel_write(file, data, enclen, 0);
+		if (written != enclen) {
 			ret = written;
 			if (written >= 0)
 				ret = -ENOMEM;
@@ -92,12 +184,15 @@ int big_key_preparse(struct key_preparsed_payload *prep)
 		/* Pin the mount and dentry to the key so that we can open it again
 		 * later
 		 */
+		prep->payload.data[big_key_data] = enckey;
 		*path = file->f_path;
 		path_get(path);
 		fput(file);
+		kfree(data);
 	} else {
 		/* Just store the data in a buffer */
 		void *data = kmalloc(datalen, GFP_KERNEL);
+
 		if (!data)
 			return -ENOMEM;
 
@@ -108,7 +203,10 @@ int big_key_preparse(struct key_preparsed_payload *prep)
 
 err_fput:
 	fput(file);
+err_enckey:
+	kfree(enckey);
 error:
+	kfree(data);
 	return ret;
 }
 
@@ -119,10 +217,10 @@ void big_key_free_preparse(struct key_preparsed_payload *prep)
 {
 	if (prep->datalen > BIG_KEY_FILE_THRESHOLD) {
 		struct path *path = (struct path *)&prep->payload.data[big_key_path];
+
 		path_put(path);
-	} else {
-		kfree(prep->payload.data[big_key_data]);
 	}
+	kfree(prep->payload.data[big_key_data]);
 }
 
 /*
@@ -147,15 +245,15 @@ void big_key_destroy(struct key *key)
 {
 	size_t datalen = (size_t)key->payload.data[big_key_len];
 
-	if (datalen) {
+	if (datalen > BIG_KEY_FILE_THRESHOLD) {
 		struct path *path = (struct path *)&key->payload.data[big_key_path];
+
 		path_put(path);
 		path->mnt = NULL;
 		path->dentry = NULL;
-	} else {
-		kfree(key->payload.data[big_key_data]);
-		key->payload.data[big_key_data] = NULL;
 	}
+	kfree(key->payload.data[big_key_data]);
+	key->payload.data[big_key_data] = NULL;
 }
 
 /*
@@ -188,17 +286,41 @@ long big_key_read(const struct key *key, char __user *buffer, size_t buflen)
 	if (datalen > BIG_KEY_FILE_THRESHOLD) {
 		struct path *path = (struct path *)&key->payload.data[big_key_path];
 		struct file *file;
-		loff_t pos;
+		u8 *data;
+		u8 *enckey = (u8 *)key->payload.data[big_key_data];
+		size_t enclen = ALIGN(datalen, crypto_blkcipher_blocksize(big_key_blkcipher));
+
+		data = kmalloc(enclen, GFP_KERNEL);
+		if (!data)
+			return -ENOMEM;
 
 		file = dentry_open(path, O_RDONLY, current_cred());
-		if (IS_ERR(file))
-			return PTR_ERR(file);
+		if (IS_ERR(file)) {
+			ret = PTR_ERR(file);
+			goto error;
+		}
 
-		pos = 0;
-		ret = vfs_read(file, buffer, datalen, &pos);
-		fput(file);
-		if (ret >= 0 && ret != datalen)
+		/* read file to kernel and decrypt */
+		ret = kernel_read(file, 0, data, enclen);
+		if (ret >= 0 && ret != enclen) {
 			ret = -EIO;
+			goto err_fput;
+		}
+
+		ret = big_key_crypt(BIG_KEY_DEC, data, enclen, enckey);
+		if (ret)
+			goto err_fput;
+
+		ret = datalen;
+
+		/* copy decrypted data to user */
+		if (copy_to_user(buffer, data, datalen) != 0)
+			ret = -EFAULT;
+
+err_fput:
+		fput(file);
+error:
+		kfree(data);
 	} else {
 		ret = datalen;
 		if (copy_to_user(buffer, key->payload.data[big_key_data],
@@ -209,8 +331,48 @@ long big_key_read(const struct key *key, char __user *buffer, size_t buflen)
 	return ret;
 }
 
+/*
+ * Register key type
+ */
 static int __init big_key_init(void)
 {
 	return register_key_type(&key_type_big_key);
 }
+
+/*
+ * Initialize big_key crypto and RNG algorithms
+ */
+static int __init big_key_crypto_init(void)
+{
+	int ret = -EINVAL;
+
+	/* init RNG */
+	big_key_rng = crypto_alloc_rng(big_key_rng_name, 0, 0);
+	if (IS_ERR(big_key_rng)) {
+		big_key_rng = NULL;
+		return -EFAULT;
+	}
+
+	/* seed RNG */
+	ret = crypto_rng_reset(big_key_rng, NULL, crypto_rng_seedsize(big_key_rng));
+	if (ret)
+		goto error;
+
+	/* init block cipher */
+	big_key_blkcipher = crypto_alloc_blkcipher(big_key_alg_name, 0, 0);
+	if (IS_ERR(big_key_blkcipher)) {
+		big_key_blkcipher = NULL;
+		ret = -EFAULT;
+		goto error;
+	}
+
+	return 0;
+
+error:
+	crypto_free_rng(big_key_rng);
+	big_key_rng = NULL;
+	return ret;
+}
+
 device_initcall(big_key_init);
+late_initcall(big_key_crypto_init);
diff --git a/security/keys/compat.c b/security/keys/compat.c
index 25430a3..c8783b3 100644
--- a/security/keys/compat.c
+++ b/security/keys/compat.c
@@ -132,6 +132,10 @@ COMPAT_SYSCALL_DEFINE5(keyctl, u32, option,
 	case KEYCTL_GET_PERSISTENT:
 		return keyctl_get_persistent(arg2, arg3);
 
+	case KEYCTL_DH_COMPUTE:
+		return keyctl_dh_compute(compat_ptr(arg2), compat_ptr(arg3),
+					 arg4);
+
 	default:
 		return -EOPNOTSUPP;
 	}
diff --git a/security/keys/dh.c b/security/keys/dh.c
new file mode 100644
index 0000000..880505a
--- /dev/null
+++ b/security/keys/dh.c
@@ -0,0 +1,160 @@
+/* Crypto operations using stored keys
+ *
+ * Copyright (c) 2016, Intel Corporation
+ *
+ * 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; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/mpi.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <keys/user-type.h>
+#include "internal.h"
+
+/*
+ * Public key or shared secret generation function [RFC2631 sec 2.1.1]
+ *
+ * ya = g^xa mod p;
+ * or
+ * ZZ = yb^xa mod p;
+ *
+ * where xa is the local private key, ya is the local public key, g is
+ * the generator, p is the prime, yb is the remote public key, and ZZ
+ * is the shared secret.
+ *
+ * Both are the same calculation, so g or yb are the "base" and ya or
+ * ZZ are the "result".
+ */
+static int do_dh(MPI result, MPI base, MPI xa, MPI p)
+{
+	return mpi_powm(result, base, xa, p);
+}
+
+static ssize_t mpi_from_key(key_serial_t keyid, size_t maxlen, MPI *mpi)
+{
+	struct key *key;
+	key_ref_t key_ref;
+	long status;
+	ssize_t ret;
+
+	key_ref = lookup_user_key(keyid, 0, KEY_NEED_READ);
+	if (IS_ERR(key_ref)) {
+		ret = -ENOKEY;
+		goto error;
+	}
+
+	key = key_ref_to_ptr(key_ref);
+
+	ret = -EOPNOTSUPP;
+	if (key->type == &key_type_user) {
+		down_read(&key->sem);
+		status = key_validate(key);
+		if (status == 0) {
+			const struct user_key_payload *payload;
+
+			payload = user_key_payload(key);
+
+			if (maxlen == 0) {
+				*mpi = NULL;
+				ret = payload->datalen;
+			} else if (payload->datalen <= maxlen) {
+				*mpi = mpi_read_raw_data(payload->data,
+							 payload->datalen);
+				if (*mpi)
+					ret = payload->datalen;
+			} else {
+				ret = -EINVAL;
+			}
+		}
+		up_read(&key->sem);
+	}
+
+	key_put(key);
+error:
+	return ret;
+}
+
+long keyctl_dh_compute(struct keyctl_dh_params __user *params,
+		       char __user *buffer, size_t buflen)
+{
+	long ret;
+	MPI base, private, prime, result;
+	unsigned nbytes;
+	struct keyctl_dh_params pcopy;
+	uint8_t *kbuf;
+	ssize_t keylen;
+	size_t resultlen;
+
+	if (!params || (!buffer && buflen)) {
+		ret = -EINVAL;
+		goto out;
+	}
+	if (copy_from_user(&pcopy, params, sizeof(pcopy)) != 0) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	keylen = mpi_from_key(pcopy.prime, buflen, &prime);
+	if (keylen < 0 || !prime) {
+		/* buflen == 0 may be used to query the required buffer size,
+		 * which is the prime key length.
+		 */
+		ret = keylen;
+		goto out;
+	}
+
+	/* The result is never longer than the prime */
+	resultlen = keylen;
+
+	keylen = mpi_from_key(pcopy.base, SIZE_MAX, &base);
+	if (keylen < 0 || !base) {
+		ret = keylen;
+		goto error1;
+	}
+
+	keylen = mpi_from_key(pcopy.private, SIZE_MAX, &private);
+	if (keylen < 0 || !private) {
+		ret = keylen;
+		goto error2;
+	}
+
+	result = mpi_alloc(0);
+	if (!result) {
+		ret = -ENOMEM;
+		goto error3;
+	}
+
+	kbuf = kmalloc(resultlen, GFP_KERNEL);
+	if (!kbuf) {
+		ret = -ENOMEM;
+		goto error4;
+	}
+
+	ret = do_dh(result, base, private, prime);
+	if (ret)
+		goto error5;
+
+	ret = mpi_read_buffer(result, kbuf, resultlen, &nbytes, NULL);
+	if (ret != 0)
+		goto error5;
+
+	ret = nbytes;
+	if (copy_to_user(buffer, kbuf, nbytes) != 0)
+		ret = -EFAULT;
+
+error5:
+	kfree(kbuf);
+error4:
+	mpi_free(result);
+error3:
+	mpi_free(private);
+error2:
+	mpi_free(base);
+error1:
+	mpi_free(prime);
+out:
+	return ret;
+}
diff --git a/security/keys/internal.h b/security/keys/internal.h
index 5105c2c..8ec7a52 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -15,6 +15,7 @@
 #include <linux/sched.h>
 #include <linux/key-type.h>
 #include <linux/task_work.h>
+#include <linux/keyctl.h>
 
 struct iovec;
 
@@ -257,6 +258,17 @@ static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring)
 }
 #endif
 
+#ifdef CONFIG_KEY_DH_OPERATIONS
+extern long keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
+			      size_t);
+#else
+static inline long keyctl_dh_compute(struct keyctl_dh_params __user *params,
+				     char __user *buffer, size_t buflen)
+{
+	return -EOPNOTSUPP;
+}
+#endif
+
 /*
  * Debugging key validation
  */
diff --git a/security/keys/key.c b/security/keys/key.c
index b287551..bd5a272 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -201,6 +201,7 @@ serial_exists:
  * @cred: The credentials specifying UID namespace.
  * @perm: The permissions mask of the new key.
  * @flags: Flags specifying quota properties.
+ * @restrict_link: Optional link restriction method for new keyrings.
  *
  * Allocate a key of the specified type with the attributes given.  The key is
  * returned in an uninstantiated state and the caller needs to instantiate the
@@ -223,7 +224,10 @@ serial_exists:
  */
 struct key *key_alloc(struct key_type *type, const char *desc,
 		      kuid_t uid, kgid_t gid, const struct cred *cred,
-		      key_perm_t perm, unsigned long flags)
+		      key_perm_t perm, unsigned long flags,
+		      int (*restrict_link)(struct key *,
+					   const struct key_type *,
+					   const union key_payload *))
 {
 	struct key_user *user = NULL;
 	struct key *key;
@@ -291,11 +295,10 @@ struct key *key_alloc(struct key_type *type, const char *desc,
 	key->uid = uid;
 	key->gid = gid;
 	key->perm = perm;
+	key->restrict_link = restrict_link;
 
 	if (!(flags & KEY_ALLOC_NOT_IN_QUOTA))
 		key->flags |= 1 << KEY_FLAG_IN_QUOTA;
-	if (flags & KEY_ALLOC_TRUSTED)
-		key->flags |= 1 << KEY_FLAG_TRUSTED;
 	if (flags & KEY_ALLOC_BUILT_IN)
 		key->flags |= 1 << KEY_FLAG_BUILTIN;
 
@@ -496,6 +499,12 @@ int key_instantiate_and_link(struct key *key,
 	}
 
 	if (keyring) {
+		if (keyring->restrict_link) {
+			ret = keyring->restrict_link(keyring, key->type,
+						     &prep.payload);
+			if (ret < 0)
+				goto error;
+		}
 		ret = __key_link_begin(keyring, &key->index_key, &edit);
 		if (ret < 0)
 			goto error;
@@ -551,8 +560,12 @@ int key_reject_and_link(struct key *key,
 	awaken = 0;
 	ret = -EBUSY;
 
-	if (keyring)
+	if (keyring) {
+		if (keyring->restrict_link)
+			return -EPERM;
+
 		link_ret = __key_link_begin(keyring, &key->index_key, &edit);
+	}
 
 	mutex_lock(&key_construction_mutex);
 
@@ -793,6 +806,9 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
 	struct key *keyring, *key = NULL;
 	key_ref_t key_ref;
 	int ret;
+	int (*restrict_link)(struct key *,
+			     const struct key_type *,
+			     const union key_payload *) = NULL;
 
 	/* look up the key type to see if it's one of the registered kernel
 	 * types */
@@ -811,6 +827,10 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
 
 	key_check(keyring);
 
+	key_ref = ERR_PTR(-EPERM);
+	if (!(flags & KEY_ALLOC_BYPASS_RESTRICTION))
+		restrict_link = keyring->restrict_link;
+
 	key_ref = ERR_PTR(-ENOTDIR);
 	if (keyring->type != &key_type_keyring)
 		goto error_put_type;
@@ -819,7 +839,6 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
 	prep.data = payload;
 	prep.datalen = plen;
 	prep.quotalen = index_key.type->def_datalen;
-	prep.trusted = flags & KEY_ALLOC_TRUSTED;
 	prep.expiry = TIME_T_MAX;
 	if (index_key.type->preparse) {
 		ret = index_key.type->preparse(&prep);
@@ -835,10 +854,13 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
 	}
 	index_key.desc_len = strlen(index_key.description);
 
-	key_ref = ERR_PTR(-EPERM);
-	if (!prep.trusted && test_bit(KEY_FLAG_TRUSTED_ONLY, &keyring->flags))
-		goto error_free_prep;
-	flags |= prep.trusted ? KEY_ALLOC_TRUSTED : 0;
+	if (restrict_link) {
+		ret = restrict_link(keyring, index_key.type, &prep.payload);
+		if (ret < 0) {
+			key_ref = ERR_PTR(ret);
+			goto error_free_prep;
+		}
+	}
 
 	ret = __key_link_begin(keyring, &index_key, &edit);
 	if (ret < 0) {
@@ -879,7 +901,7 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
 
 	/* allocate a new key */
 	key = key_alloc(index_key.type, index_key.description,
-			cred->fsuid, cred->fsgid, cred, perm, flags);
+			cred->fsuid, cred->fsgid, cred, perm, flags, NULL);
 	if (IS_ERR(key)) {
 		key_ref = ERR_CAST(key);
 		goto error_link_end;
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index ed73c6c..3b135a0 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -1686,6 +1686,11 @@ SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3,
 	case KEYCTL_GET_PERSISTENT:
 		return keyctl_get_persistent((uid_t)arg2, (key_serial_t)arg3);
 
+	case KEYCTL_DH_COMPUTE:
+		return keyctl_dh_compute((struct keyctl_dh_params __user *) arg2,
+					 (char __user *) arg3,
+					 (size_t) arg4);
+
 	default:
 		return -EOPNOTSUPP;
 	}
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index f931ccf..c91e4e0 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -491,13 +491,17 @@ static long keyring_read(const struct key *keyring,
  */
 struct key *keyring_alloc(const char *description, kuid_t uid, kgid_t gid,
 			  const struct cred *cred, key_perm_t perm,
-			  unsigned long flags, struct key *dest)
+			  unsigned long flags,
+			  int (*restrict_link)(struct key *,
+					       const struct key_type *,
+					       const union key_payload *),
+			  struct key *dest)
 {
 	struct key *keyring;
 	int ret;
 
 	keyring = key_alloc(&key_type_keyring, description,
-			    uid, gid, cred, perm, flags);
+			    uid, gid, cred, perm, flags, restrict_link);
 	if (!IS_ERR(keyring)) {
 		ret = key_instantiate_and_link(keyring, NULL, 0, dest, NULL);
 		if (ret < 0) {
@@ -510,6 +514,26 @@ struct key *keyring_alloc(const char *description, kuid_t uid, kgid_t gid,
 }
 EXPORT_SYMBOL(keyring_alloc);
 
+/**
+ * restrict_link_reject - Give -EPERM to restrict link
+ * @keyring: The keyring being added to.
+ * @type: The type of key being added.
+ * @payload: The payload of the key intended to be added.
+ *
+ * Reject the addition of any links to a keyring.  It can be overridden by
+ * passing KEY_ALLOC_BYPASS_RESTRICTION to key_instantiate_and_link() when
+ * adding a key to a keyring.
+ *
+ * This is meant to be passed as the restrict_link parameter to
+ * keyring_alloc().
+ */
+int restrict_link_reject(struct key *keyring,
+			 const struct key_type *type,
+			 const union key_payload *payload)
+{
+	return -EPERM;
+}
+
 /*
  * By default, we keys found by getting an exact match on their descriptions.
  */
@@ -1191,6 +1215,16 @@ void __key_link_end(struct key *keyring,
 	up_write(&keyring->sem);
 }
 
+/*
+ * Check addition of keys to restricted keyrings.
+ */
+static int __key_link_check_restriction(struct key *keyring, struct key *key)
+{
+	if (!keyring->restrict_link)
+		return 0;
+	return keyring->restrict_link(keyring, key->type, &key->payload);
+}
+
 /**
  * key_link - Link a key to a keyring
  * @keyring: The keyring to make the link in.
@@ -1221,14 +1255,12 @@ int key_link(struct key *keyring, struct key *key)
 	key_check(keyring);
 	key_check(key);
 
-	if (test_bit(KEY_FLAG_TRUSTED_ONLY, &keyring->flags) &&
-	    !test_bit(KEY_FLAG_TRUSTED, &key->flags))
-		return -EPERM;
-
 	ret = __key_link_begin(keyring, &key->index_key, &edit);
 	if (ret == 0) {
 		kdebug("begun {%d,%d}", keyring->serial, atomic_read(&keyring->usage));
-		ret = __key_link_check_live_key(keyring, key);
+		ret = __key_link_check_restriction(keyring, key);
+		if (ret == 0)
+			ret = __key_link_check_live_key(keyring, key);
 		if (ret == 0)
 			__key_link(key, &edit);
 		__key_link_end(keyring, &key->index_key, edit);
diff --git a/security/keys/persistent.c b/security/keys/persistent.c
index c9fae5e..2ef45b3 100644
--- a/security/keys/persistent.c
+++ b/security/keys/persistent.c
@@ -26,7 +26,7 @@ static int key_create_persistent_register(struct user_namespace *ns)
 					current_cred(),
 					((KEY_POS_ALL & ~KEY_POS_SETATTR) |
 					 KEY_USR_VIEW | KEY_USR_READ),
-					KEY_ALLOC_NOT_IN_QUOTA, NULL);
+					KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
 	if (IS_ERR(reg))
 		return PTR_ERR(reg);
 
@@ -60,7 +60,7 @@ static key_ref_t key_create_persistent(struct user_namespace *ns, kuid_t uid,
 				   uid, INVALID_GID, current_cred(),
 				   ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
 				    KEY_USR_VIEW | KEY_USR_READ),
-				   KEY_ALLOC_NOT_IN_QUOTA,
+				   KEY_ALLOC_NOT_IN_QUOTA, NULL,
 				   ns->persistent_keyring_register);
 	if (IS_ERR(persistent))
 		return ERR_CAST(persistent);
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index e6d50172..40a8852 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -76,7 +76,8 @@ int install_user_keyrings(void)
 		if (IS_ERR(uid_keyring)) {
 			uid_keyring = keyring_alloc(buf, user->uid, INVALID_GID,
 						    cred, user_keyring_perm,
-						    KEY_ALLOC_IN_QUOTA, NULL);
+						    KEY_ALLOC_IN_QUOTA,
+						    NULL, NULL);
 			if (IS_ERR(uid_keyring)) {
 				ret = PTR_ERR(uid_keyring);
 				goto error;
@@ -92,7 +93,8 @@ int install_user_keyrings(void)
 			session_keyring =
 				keyring_alloc(buf, user->uid, INVALID_GID,
 					      cred, user_keyring_perm,
-					      KEY_ALLOC_IN_QUOTA, NULL);
+					      KEY_ALLOC_IN_QUOTA,
+					      NULL, NULL);
 			if (IS_ERR(session_keyring)) {
 				ret = PTR_ERR(session_keyring);
 				goto error_release;
@@ -134,7 +136,8 @@ int install_thread_keyring_to_cred(struct cred *new)
 
 	keyring = keyring_alloc("_tid", new->uid, new->gid, new,
 				KEY_POS_ALL | KEY_USR_VIEW,
-				KEY_ALLOC_QUOTA_OVERRUN, NULL);
+				KEY_ALLOC_QUOTA_OVERRUN,
+				NULL, NULL);
 	if (IS_ERR(keyring))
 		return PTR_ERR(keyring);
 
@@ -180,7 +183,8 @@ int install_process_keyring_to_cred(struct cred *new)
 
 	keyring = keyring_alloc("_pid", new->uid, new->gid, new,
 				KEY_POS_ALL | KEY_USR_VIEW,
-				KEY_ALLOC_QUOTA_OVERRUN, NULL);
+				KEY_ALLOC_QUOTA_OVERRUN,
+				NULL, NULL);
 	if (IS_ERR(keyring))
 		return PTR_ERR(keyring);
 
@@ -231,7 +235,7 @@ int install_session_keyring_to_cred(struct cred *cred, struct key *keyring)
 
 		keyring = keyring_alloc("_ses", cred->uid, cred->gid, cred,
 					KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ,
-					flags, NULL);
+					flags, NULL, NULL);
 		if (IS_ERR(keyring))
 			return PTR_ERR(keyring);
 	} else {
@@ -785,7 +789,7 @@ long join_session_keyring(const char *name)
 		keyring = keyring_alloc(
 			name, old->uid, old->gid, old,
 			KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ | KEY_USR_LINK,
-			KEY_ALLOC_IN_QUOTA, NULL);
+			KEY_ALLOC_IN_QUOTA, NULL, NULL);
 		if (IS_ERR(keyring)) {
 			ret = PTR_ERR(keyring);
 			goto error2;
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index c7a117c..a29e355 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -116,7 +116,7 @@ static int call_sbin_request_key(struct key_construction *cons,
 	cred = get_current_cred();
 	keyring = keyring_alloc(desc, cred->fsuid, cred->fsgid, cred,
 				KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ,
-				KEY_ALLOC_QUOTA_OVERRUN, NULL);
+				KEY_ALLOC_QUOTA_OVERRUN, NULL, NULL);
 	put_cred(cred);
 	if (IS_ERR(keyring)) {
 		ret = PTR_ERR(keyring);
@@ -355,7 +355,7 @@ static int construct_alloc_key(struct keyring_search_context *ctx,
 
 	key = key_alloc(ctx->index_key.type, ctx->index_key.description,
 			ctx->cred->fsuid, ctx->cred->fsgid, ctx->cred,
-			perm, flags);
+			perm, flags, NULL);
 	if (IS_ERR(key))
 		goto alloc_failed;
 
diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c
index 4f0f112..9db8b4a 100644
--- a/security/keys/request_key_auth.c
+++ b/security/keys/request_key_auth.c
@@ -202,7 +202,7 @@ struct key *request_key_auth_new(struct key *target, const void *callout_info,
 	authkey = key_alloc(&key_type_request_key_auth, desc,
 			    cred->fsuid, cred->fsgid, cred,
 			    KEY_POS_VIEW | KEY_POS_READ | KEY_POS_SEARCH |
-			    KEY_USR_VIEW, KEY_ALLOC_NOT_IN_QUOTA);
+			    KEY_USR_VIEW, KEY_ALLOC_NOT_IN_QUOTA, NULL);
 	if (IS_ERR(authkey)) {
 		ret = PTR_ERR(authkey);
 		goto error_alloc;
diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c
index 8705d79..66b1840 100644
--- a/security/keys/user_defined.c
+++ b/security/keys/user_defined.c
@@ -96,45 +96,25 @@ EXPORT_SYMBOL_GPL(user_free_preparse);
  */
 int user_update(struct key *key, struct key_preparsed_payload *prep)
 {
-	struct user_key_payload *upayload, *zap;
-	size_t datalen = prep->datalen;
+	struct user_key_payload *zap = NULL;
 	int ret;
 
-	ret = -EINVAL;
-	if (datalen <= 0 || datalen > 32767 || !prep->data)
-		goto error;
-
-	/* construct a replacement payload */
-	ret = -ENOMEM;
-	upayload = kmalloc(sizeof(*upayload) + datalen, GFP_KERNEL);
-	if (!upayload)
-		goto error;
-
-	upayload->datalen = datalen;
-	memcpy(upayload->data, prep->data, datalen);
-
 	/* check the quota and attach the new data */
-	zap = upayload;
-
-	ret = key_payload_reserve(key, datalen);
-
-	if (ret == 0) {
-		/* attach the new data, displacing the old */
-		if (!test_bit(KEY_FLAG_NEGATIVE, &key->flags))
-			zap = key->payload.data[0];
-		else
-			zap = NULL;
-		rcu_assign_keypointer(key, upayload);
-		key->expiry = 0;
-	}
+	ret = key_payload_reserve(key, prep->datalen);
+	if (ret < 0)
+		return ret;
+
+	/* attach the new data, displacing the old */
+	key->expiry = prep->expiry;
+	if (!test_bit(KEY_FLAG_NEGATIVE, &key->flags))
+		zap = rcu_dereference_key(key);
+	rcu_assign_keypointer(key, prep->payload.data[0]);
+	prep->payload.data[0] = NULL;
 
 	if (zap)
 		kfree_rcu(zap, rcu);
-
-error:
 	return ret;
 }
-
 EXPORT_SYMBOL_GPL(user_update);
 
 /*