sync to Linus v4.13-rc2 for subsystem developers to work against

24 files changed, 365 insertions, 334 deletions

diff --git a/security/Kconfig b/security/Kconfig
index d540bfe73190..e8e449444e65 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -163,6 +163,13 @@ config HARDENED_USERCOPY_PAGESPAN
 	  been removed. This config is intended to be used only while
 	  trying to find such users.
 
+config FORTIFY_SOURCE
+	bool "Harden common str/mem functions against buffer overflows"
+	depends on ARCH_HAS_FORTIFY_SOURCE
+	help
+	  Detect overflows of buffers in common string and memory functions
+	  where the compiler can determine and validate the buffer sizes.
+
 config STATIC_USERMODEHELPER
 	bool "Force all usermode helper calls through a single binary"
 	help
diff --git a/security/apparmor/match.c b/security/apparmor/match.c
index 960c913381e2..72c604350e80 100644
--- a/security/apparmor/match.c
+++ b/security/apparmor/match.c
@@ -226,7 +226,7 @@ void aa_dfa_free_kref(struct kref *kref)
  * @flags: flags controlling what type of accept tables are acceptable
  *
  * Unpack a dfa that has been serialized.  To find information on the dfa
- * format look in Documentation/security/apparmor.txt
+ * format look in Documentation/admin-guide/LSM/apparmor.rst
  * Assumes the dfa @blob stream has been aligned on a 8 byte boundary
  *
  * Returns: an unpacked dfa ready for matching or ERR_PTR on failure
diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c
index 6e6f8c1a10a9..c600f4dd1783 100644
--- a/security/apparmor/policy_unpack.c
+++ b/security/apparmor/policy_unpack.c
@@ -13,7 +13,7 @@
  * License.
  *
  * AppArmor uses a serialized binary format for loading policy. To find
- * policy format documentation look in Documentation/security/apparmor.txt
+ * policy format documentation see Documentation/admin-guide/LSM/apparmor.rst
  * All policy is validated before it is used.
  */
 
diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c
index d7f282d75cc1..1d32cd20009a 100644
--- a/security/integrity/evm/evm_crypto.c
+++ b/security/integrity/evm/evm_crypto.c
@@ -164,7 +164,7 @@ static void hmac_add_misc(struct shash_desc *desc, struct inode *inode,
 	hmac_misc.mode = inode->i_mode;
 	crypto_shash_update(desc, (const u8 *)&hmac_misc, sizeof(hmac_misc));
 	if (evm_hmac_attrs & EVM_ATTR_FSUUID)
-		crypto_shash_update(desc, inode->i_sb->s_uuid,
+		crypto_shash_update(desc, &inode->i_sb->s_uuid.b[0],
 				    sizeof(inode->i_sb->s_uuid));
 	crypto_shash_final(desc, digest);
 }
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index f4436626ccb7..95209a5f8595 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -61,7 +61,7 @@ struct ima_rule_entry {
 	enum ima_hooks func;
 	int mask;
 	unsigned long fsmagic;
-	u8 fsuuid[16];
+	uuid_t fsuuid;
 	kuid_t uid;
 	kuid_t fowner;
 	bool (*uid_op)(kuid_t, kuid_t);    /* Handlers for operators       */
@@ -266,7 +266,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 	    && rule->fsmagic != inode->i_sb->s_magic)
 		return false;
 	if ((rule->flags & IMA_FSUUID) &&
-	    memcmp(rule->fsuuid, inode->i_sb->s_uuid, sizeof(rule->fsuuid)))
+	    !uuid_equal(&rule->fsuuid, &inode->i_sb->s_uuid))
 		return false;
 	if ((rule->flags & IMA_UID) && !rule->uid_op(cred->uid, rule->uid))
 		return false;
@@ -743,14 +743,12 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 		case Opt_fsuuid:
 			ima_log_string(ab, "fsuuid", args[0].from);
 
-			if (memchr_inv(entry->fsuuid, 0x00,
-				       sizeof(entry->fsuuid))) {
+			if (uuid_is_null(&entry->fsuuid)) {
 				result = -EINVAL;
 				break;
 			}
 
-			result = blk_part_pack_uuid(args[0].from,
-						    entry->fsuuid);
+			result = uuid_parse(args[0].from, &entry->fsuuid);
 			if (!result)
 				entry->flags |= IMA_FSUUID;
 			break;
@@ -1073,7 +1071,7 @@ int ima_policy_show(struct seq_file *m, void *v)
 	}
 
 	if (entry->flags & IMA_FSUUID) {
-		seq_printf(m, "fsuuid=%pU", entry->fsuuid);
+		seq_printf(m, "fsuuid=%pU", &entry->fsuuid);
 		seq_puts(m, " ");
 	}
 
diff --git a/security/keys/Kconfig b/security/keys/Kconfig
index 6fd95f76bfae..a7a23b5541f8 100644
--- a/security/keys/Kconfig
+++ b/security/keys/Kconfig
@@ -20,6 +20,10 @@ config KEYS
 
 	  If you are unsure as to whether this is required, answer N.
 
+config KEYS_COMPAT
+	def_bool y
+	depends on COMPAT && KEYS
+
 config PERSISTENT_KEYRINGS
 	bool "Enable register of persistent per-UID keyrings"
 	depends on KEYS
@@ -89,9 +93,9 @@ config ENCRYPTED_KEYS
 config KEY_DH_OPERATIONS
        bool "Diffie-Hellman operations on retained keys"
        depends on KEYS
-       select MPILIB
        select CRYPTO
        select CRYPTO_HASH
+       select CRYPTO_DH
        help
 	 This option provides support for calculating Diffie-Hellman
 	 public keys and shared secrets using values stored as keys
diff --git a/security/keys/compat_dh.c b/security/keys/compat_dh.c
index a6a659b6bcb6..aa6b34cafe5f 100644
--- a/security/keys/compat_dh.c
+++ b/security/keys/compat_dh.c
@@ -33,6 +33,8 @@ long compat_keyctl_dh_compute(struct keyctl_dh_params __user *params,
 	kdfcopy.hashname = compat_ptr(compat_kdfcopy.hashname);
 	kdfcopy.otherinfo = compat_ptr(compat_kdfcopy.otherinfo);
 	kdfcopy.otherinfolen = compat_kdfcopy.otherinfolen;
+	memcpy(kdfcopy.__spare, compat_kdfcopy.__spare,
+	       sizeof(kdfcopy.__spare));
 
 	return __keyctl_dh_compute(params, buffer, buflen, &kdfcopy);
 }
diff --git a/security/keys/dh.c b/security/keys/dh.c
index e603bd912e4c..d1ea9f325f94 100644
--- a/security/keys/dh.c
+++ b/security/keys/dh.c
@@ -8,34 +8,17 @@
  * 2 of the License, or (at your option) any later version.
  */
 
-#include <linux/mpi.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
+#include <linux/scatterlist.h>
 #include <linux/crypto.h>
 #include <crypto/hash.h>
+#include <crypto/kpp.h>
+#include <crypto/dh.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)
+static ssize_t dh_data_from_key(key_serial_t keyid, void **data)
 {
 	struct key *key;
 	key_ref_t key_ref;
@@ -56,19 +39,17 @@ static ssize_t mpi_from_key(key_serial_t keyid, size_t maxlen, MPI *mpi)
 		status = key_validate(key);
 		if (status == 0) {
 			const struct user_key_payload *payload;
+			uint8_t *duplicate;
 
 			payload = user_key_payload_locked(key);
 
-			if (maxlen == 0) {
-				*mpi = NULL;
+			duplicate = kmemdup(payload->data, payload->datalen,
+					    GFP_KERNEL);
+			if (duplicate) {
+				*data = duplicate;
 				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;
+				ret = -ENOMEM;
 			}
 		}
 		up_read(&key->sem);
@@ -79,6 +60,29 @@ error:
 	return ret;
 }
 
+static void dh_free_data(struct dh *dh)
+{
+	kzfree(dh->key);
+	kzfree(dh->p);
+	kzfree(dh->g);
+}
+
+struct dh_completion {
+	struct completion completion;
+	int err;
+};
+
+static void dh_crypto_done(struct crypto_async_request *req, int err)
+{
+	struct dh_completion *compl = req->data;
+
+	if (err == -EINPROGRESS)
+		return;
+
+	compl->err = err;
+	complete(&compl->completion);
+}
+
 struct kdf_sdesc {
 	struct shash_desc shash;
 	char ctx[];
@@ -89,6 +93,7 @@ static int kdf_alloc(struct kdf_sdesc **sdesc_ret, char *hashname)
 	struct crypto_shash *tfm;
 	struct kdf_sdesc *sdesc;
 	int size;
+	int err;
 
 	/* allocate synchronous hash */
 	tfm = crypto_alloc_shash(hashname, 0, 0);
@@ -97,16 +102,25 @@ static int kdf_alloc(struct kdf_sdesc **sdesc_ret, char *hashname)
 		return PTR_ERR(tfm);
 	}
 
+	err = -EINVAL;
+	if (crypto_shash_digestsize(tfm) == 0)
+		goto out_free_tfm;
+
+	err = -ENOMEM;
 	size = sizeof(struct shash_desc) + crypto_shash_descsize(tfm);
 	sdesc = kmalloc(size, GFP_KERNEL);
 	if (!sdesc)
-		return -ENOMEM;
+		goto out_free_tfm;
 	sdesc->shash.tfm = tfm;
 	sdesc->shash.flags = 0x0;
 
 	*sdesc_ret = sdesc;
 
 	return 0;
+
+out_free_tfm:
+	crypto_free_shash(tfm);
+	return err;
 }
 
 static void kdf_dealloc(struct kdf_sdesc *sdesc)
@@ -120,14 +134,6 @@ static void kdf_dealloc(struct kdf_sdesc *sdesc)
 	kzfree(sdesc);
 }
 
-/* convert 32 bit integer into its string representation */
-static inline void crypto_kw_cpu_to_be32(u32 val, u8 *buf)
-{
-	__be32 *a = (__be32 *)buf;
-
-	*a = cpu_to_be32(val);
-}
-
 /*
  * Implementation of the KDF in counter mode according to SP800-108 section 5.1
  * as well as SP800-56A section 5.8.1 (Single-step KDF).
@@ -138,25 +144,39 @@ static inline void crypto_kw_cpu_to_be32(u32 val, u8 *buf)
  * 5.8.1.2).
  */
 static int kdf_ctr(struct kdf_sdesc *sdesc, const u8 *src, unsigned int slen,
-		   u8 *dst, unsigned int dlen)
+		   u8 *dst, unsigned int dlen, unsigned int zlen)
 {
 	struct shash_desc *desc = &sdesc->shash;
 	unsigned int h = crypto_shash_digestsize(desc->tfm);
 	int err = 0;
 	u8 *dst_orig = dst;
-	u32 i = 1;
-	u8 iteration[sizeof(u32)];
+	__be32 counter = cpu_to_be32(1);
 
 	while (dlen) {
 		err = crypto_shash_init(desc);
 		if (err)
 			goto err;
 
-		crypto_kw_cpu_to_be32(i, iteration);
-		err = crypto_shash_update(desc, iteration, sizeof(u32));
+		err = crypto_shash_update(desc, (u8 *)&counter, sizeof(__be32));
 		if (err)
 			goto err;
 
+		if (zlen && h) {
+			u8 tmpbuffer[h];
+			size_t chunk = min_t(size_t, zlen, h);
+			memset(tmpbuffer, 0, chunk);
+
+			do {
+				err = crypto_shash_update(desc, tmpbuffer,
+							  chunk);
+				if (err)
+					goto err;
+
+				zlen -= chunk;
+				chunk = min_t(size_t, zlen, h);
+			} while (zlen);
+		}
+
 		if (src && slen) {
 			err = crypto_shash_update(desc, src, slen);
 			if (err)
@@ -179,7 +199,7 @@ static int kdf_ctr(struct kdf_sdesc *sdesc, const u8 *src, unsigned int slen,
 
 			dlen -= h;
 			dst += h;
-			i++;
+			counter = cpu_to_be32(be32_to_cpu(counter) + 1);
 		}
 	}
 
@@ -192,7 +212,7 @@ err:
 
 static int keyctl_dh_compute_kdf(struct kdf_sdesc *sdesc,
 				 char __user *buffer, size_t buflen,
-				 uint8_t *kbuf, size_t kbuflen)
+				 uint8_t *kbuf, size_t kbuflen, size_t lzero)
 {
 	uint8_t *outbuf = NULL;
 	int ret;
@@ -203,7 +223,7 @@ static int keyctl_dh_compute_kdf(struct kdf_sdesc *sdesc,
 		goto err;
 	}
 
-	ret = kdf_ctr(sdesc, kbuf, kbuflen, outbuf, buflen);
+	ret = kdf_ctr(sdesc, kbuf, kbuflen, outbuf, buflen, lzero);
 	if (ret)
 		goto err;
 
@@ -221,127 +241,180 @@ long __keyctl_dh_compute(struct keyctl_dh_params __user *params,
 			 struct keyctl_kdf_params *kdfcopy)
 {
 	long ret;
-	MPI base, private, prime, result;
-	unsigned nbytes;
+	ssize_t dlen;
+	int secretlen;
+	int outlen;
 	struct keyctl_dh_params pcopy;
-	uint8_t *kbuf;
-	ssize_t keylen;
-	size_t resultlen;
+	struct dh dh_inputs;
+	struct scatterlist outsg;
+	struct dh_completion compl;
+	struct crypto_kpp *tfm;
+	struct kpp_request *req;
+	uint8_t *secret;
+	uint8_t *outbuf;
 	struct kdf_sdesc *sdesc = NULL;
 
 	if (!params || (!buffer && buflen)) {
 		ret = -EINVAL;
-		goto out;
+		goto out1;
 	}
 	if (copy_from_user(&pcopy, params, sizeof(pcopy)) != 0) {
 		ret = -EFAULT;
-		goto out;
+		goto out1;
 	}
 
 	if (kdfcopy) {
 		char *hashname;
 
+		if (memchr_inv(kdfcopy->__spare, 0, sizeof(kdfcopy->__spare))) {
+			ret = -EINVAL;
+			goto out1;
+		}
+
 		if (buflen > KEYCTL_KDF_MAX_OUTPUT_LEN ||
 		    kdfcopy->otherinfolen > KEYCTL_KDF_MAX_OI_LEN) {
 			ret = -EMSGSIZE;
-			goto out;
+			goto out1;
 		}
 
 		/* get KDF name string */
 		hashname = strndup_user(kdfcopy->hashname, CRYPTO_MAX_ALG_NAME);
 		if (IS_ERR(hashname)) {
 			ret = PTR_ERR(hashname);
-			goto out;
+			goto out1;
 		}
 
 		/* allocate KDF from the kernel crypto API */
 		ret = kdf_alloc(&sdesc, hashname);
 		kfree(hashname);
 		if (ret)
-			goto out;
+			goto out1;
 	}
 
-	/*
-	 * If the caller requests postprocessing with a KDF, allow an
-	 * arbitrary output buffer size since the KDF ensures proper truncation.
-	 */
-	keylen = mpi_from_key(pcopy.prime, kdfcopy ? SIZE_MAX : 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;
+	memset(&dh_inputs, 0, sizeof(dh_inputs));
+
+	dlen = dh_data_from_key(pcopy.prime, &dh_inputs.p);
+	if (dlen < 0) {
+		ret = dlen;
+		goto out1;
+	}
+	dh_inputs.p_size = dlen;
+
+	dlen = dh_data_from_key(pcopy.base, &dh_inputs.g);
+	if (dlen < 0) {
+		ret = dlen;
+		goto out2;
+	}
+	dh_inputs.g_size = dlen;
+
+	dlen = dh_data_from_key(pcopy.private, &dh_inputs.key);
+	if (dlen < 0) {
+		ret = dlen;
+		goto out2;
 	}
+	dh_inputs.key_size = dlen;
 
-	/* The result is never longer than the prime */
-	resultlen = keylen;
+	secretlen = crypto_dh_key_len(&dh_inputs);
+	secret = kmalloc(secretlen, GFP_KERNEL);
+	if (!secret) {
+		ret = -ENOMEM;
+		goto out2;
+	}
+	ret = crypto_dh_encode_key(secret, secretlen, &dh_inputs);
+	if (ret)
+		goto out3;
 
-	keylen = mpi_from_key(pcopy.base, SIZE_MAX, &base);
-	if (keylen < 0 || !base) {
-		ret = keylen;
-		goto error1;
+	tfm = crypto_alloc_kpp("dh", CRYPTO_ALG_TYPE_KPP, 0);
+	if (IS_ERR(tfm)) {
+		ret = PTR_ERR(tfm);
+		goto out3;
 	}
 
-	keylen = mpi_from_key(pcopy.private, SIZE_MAX, &private);
-	if (keylen < 0 || !private) {
-		ret = keylen;
-		goto error2;
+	ret = crypto_kpp_set_secret(tfm, secret, secretlen);
+	if (ret)
+		goto out4;
+
+	outlen = crypto_kpp_maxsize(tfm);
+
+	if (!kdfcopy) {
+		/*
+		 * When not using a KDF, buflen 0 is used to read the
+		 * required buffer length
+		 */
+		if (buflen == 0) {
+			ret = outlen;
+			goto out4;
+		} else if (outlen > buflen) {
+			ret = -EOVERFLOW;
+			goto out4;
+		}
 	}
 
-	result = mpi_alloc(0);
-	if (!result) {
+	outbuf = kzalloc(kdfcopy ? (outlen + kdfcopy->otherinfolen) : outlen,
+			 GFP_KERNEL);
+	if (!outbuf) {
 		ret = -ENOMEM;
-		goto error3;
+		goto out4;
 	}
 
-	/* allocate space for DH shared secret and SP800-56A otherinfo */
-	kbuf = kmalloc(kdfcopy ? (resultlen + kdfcopy->otherinfolen) : resultlen,
-		       GFP_KERNEL);
-	if (!kbuf) {
+	sg_init_one(&outsg, outbuf, outlen);
+
+	req = kpp_request_alloc(tfm, GFP_KERNEL);
+	if (!req) {
 		ret = -ENOMEM;
-		goto error4;
+		goto out5;
 	}
 
+	kpp_request_set_input(req, NULL, 0);
+	kpp_request_set_output(req, &outsg, outlen);
+	init_completion(&compl.completion);
+	kpp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
+				 CRYPTO_TFM_REQ_MAY_SLEEP,
+				 dh_crypto_done, &compl);
+
 	/*
-	 * Concatenate SP800-56A otherinfo past DH shared secret -- the
-	 * input to the KDF is (DH shared secret || otherinfo)
+	 * For DH, generate_public_key and generate_shared_secret are
+	 * the same calculation
 	 */
-	if (kdfcopy && kdfcopy->otherinfo &&
-	    copy_from_user(kbuf + resultlen, kdfcopy->otherinfo,
-			   kdfcopy->otherinfolen) != 0) {
-		ret = -EFAULT;
-		goto error5;
+	ret = crypto_kpp_generate_public_key(req);
+	if (ret == -EINPROGRESS) {
+		wait_for_completion(&compl.completion);
+		ret = compl.err;
+		if (ret)
+			goto out6;
 	}
 
-	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;
-
 	if (kdfcopy) {
-		ret = keyctl_dh_compute_kdf(sdesc, buffer, buflen, kbuf,
-					    resultlen + kdfcopy->otherinfolen);
-	} else {
-		ret = nbytes;
-		if (copy_to_user(buffer, kbuf, nbytes) != 0)
+		/*
+		 * Concatenate SP800-56A otherinfo past DH shared secret -- the
+		 * input to the KDF is (DH shared secret || otherinfo)
+		 */
+		if (copy_from_user(outbuf + req->dst_len, kdfcopy->otherinfo,
+				   kdfcopy->otherinfolen) != 0) {
 			ret = -EFAULT;
+			goto out6;
+		}
+
+		ret = keyctl_dh_compute_kdf(sdesc, buffer, buflen, outbuf,
+					    req->dst_len + kdfcopy->otherinfolen,
+					    outlen - req->dst_len);
+	} else if (copy_to_user(buffer, outbuf, req->dst_len) == 0) {
+		ret = req->dst_len;
+	} else {
+		ret = -EFAULT;
 	}
 
-error5:
-	kzfree(kbuf);
-error4:
-	mpi_free(result);
-error3:
-	mpi_free(private);
-error2:
-	mpi_free(base);
-error1:
-	mpi_free(prime);
-out:
+out6:
+	kpp_request_free(req);
+out5:
+	kzfree(outbuf);
+out4:
+	crypto_free_kpp(tfm);
+out3:
+	kzfree(secret);
+out2:
+	dh_free_data(&dh_inputs);
+out1:
 	kdf_dealloc(sdesc);
 	return ret;
 }
diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c
index 0010955d7876..69855ba0d3b3 100644
--- a/security/keys/encrypted-keys/encrypted.c
+++ b/security/keys/encrypted-keys/encrypted.c
@@ -11,7 +11,7 @@
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation, version 2 of the License.
  *
- * See Documentation/security/keys-trusted-encrypted.txt
+ * See Documentation/security/keys/trusted-encrypted.rst
  */
 
 #include <linux/uaccess.h>
@@ -30,6 +30,7 @@
 #include <linux/scatterlist.h>
 #include <linux/ctype.h>
 #include <crypto/aes.h>
+#include <crypto/algapi.h>
 #include <crypto/hash.h>
 #include <crypto/sha.h>
 #include <crypto/skcipher.h>
@@ -54,13 +55,7 @@ static int blksize;
 #define MAX_DATA_SIZE 4096
 #define MIN_DATA_SIZE  20
 
-struct sdesc {
-	struct shash_desc shash;
-	char ctx[];
-};
-
-static struct crypto_shash *hashalg;
-static struct crypto_shash *hmacalg;
+static struct crypto_shash *hash_tfm;
 
 enum {
 	Opt_err = -1, Opt_new, Opt_load, Opt_update
@@ -141,23 +136,22 @@ static int valid_ecryptfs_desc(const char *ecryptfs_desc)
  */
 static int valid_master_desc(const char *new_desc, const char *orig_desc)
 {
-	if (!memcmp(new_desc, KEY_TRUSTED_PREFIX, KEY_TRUSTED_PREFIX_LEN)) {
-		if (strlen(new_desc) == KEY_TRUSTED_PREFIX_LEN)
-			goto out;
-		if (orig_desc)
-			if (memcmp(new_desc, orig_desc, KEY_TRUSTED_PREFIX_LEN))
-				goto out;
-	} else if (!memcmp(new_desc, KEY_USER_PREFIX, KEY_USER_PREFIX_LEN)) {
-		if (strlen(new_desc) == KEY_USER_PREFIX_LEN)
-			goto out;
-		if (orig_desc)
-			if (memcmp(new_desc, orig_desc, KEY_USER_PREFIX_LEN))
-				goto out;
-	} else
-		goto out;
+	int prefix_len;
+
+	if (!strncmp(new_desc, KEY_TRUSTED_PREFIX, KEY_TRUSTED_PREFIX_LEN))
+		prefix_len = KEY_TRUSTED_PREFIX_LEN;
+	else if (!strncmp(new_desc, KEY_USER_PREFIX, KEY_USER_PREFIX_LEN))
+		prefix_len = KEY_USER_PREFIX_LEN;
+	else
+		return -EINVAL;
+
+	if (!new_desc[prefix_len])
+		return -EINVAL;
+
+	if (orig_desc && strncmp(new_desc, orig_desc, prefix_len))
+		return -EINVAL;
+
 	return 0;
-out:
-	return -EINVAL;
 }
 
 /*
@@ -321,53 +315,38 @@ error:
 	return ukey;
 }
 
-static struct sdesc *alloc_sdesc(struct crypto_shash *alg)
-{
-	struct sdesc *sdesc;
-	int size;
-
-	size = sizeof(struct shash_desc) + crypto_shash_descsize(alg);
-	sdesc = kmalloc(size, GFP_KERNEL);
-	if (!sdesc)
-		return ERR_PTR(-ENOMEM);
-	sdesc->shash.tfm = alg;
-	sdesc->shash.flags = 0x0;
-	return sdesc;
-}
-
-static int calc_hmac(u8 *digest, const u8 *key, unsigned int keylen,
+static int calc_hash(struct crypto_shash *tfm, u8 *digest,
 		     const u8 *buf, unsigned int buflen)
 {
-	struct sdesc *sdesc;
-	int ret;
+	SHASH_DESC_ON_STACK(desc, tfm);
+	int err;
 
-	sdesc = alloc_sdesc(hmacalg);
-	if (IS_ERR(sdesc)) {
-		pr_info("encrypted_key: can't alloc %s\n", hmac_alg);
-		return PTR_ERR(sdesc);
-	}
+	desc->tfm = tfm;
+	desc->flags = 0;
 
-	ret = crypto_shash_setkey(hmacalg, key, keylen);
-	if (!ret)
-		ret = crypto_shash_digest(&sdesc->shash, buf, buflen, digest);
-	kfree(sdesc);
-	return ret;
+	err = crypto_shash_digest(desc, buf, buflen, digest);
+	shash_desc_zero(desc);
+	return err;
 }
 
-static int calc_hash(u8 *digest, const u8 *buf, unsigned int buflen)
+static int calc_hmac(u8 *digest, const u8 *key, unsigned int keylen,
+		     const u8 *buf, unsigned int buflen)
 {
-	struct sdesc *sdesc;
-	int ret;
+	struct crypto_shash *tfm;
+	int err;
 
-	sdesc = alloc_sdesc(hashalg);
-	if (IS_ERR(sdesc)) {
-		pr_info("encrypted_key: can't alloc %s\n", hash_alg);
-		return PTR_ERR(sdesc);
+	tfm = crypto_alloc_shash(hmac_alg, 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(tfm)) {
+		pr_err("encrypted_key: can't alloc %s transform: %ld\n",
+		       hmac_alg, PTR_ERR(tfm));
+		return PTR_ERR(tfm);
 	}
 
-	ret = crypto_shash_digest(&sdesc->shash, buf, buflen, digest);
-	kfree(sdesc);
-	return ret;
+	err = crypto_shash_setkey(tfm, key, keylen);
+	if (!err)
+		err = calc_hash(tfm, digest, buf, buflen);
+	crypto_free_shash(tfm);
+	return err;
 }
 
 enum derived_key_type { ENC_KEY, AUTH_KEY };
@@ -385,10 +364,9 @@ static int get_derived_key(u8 *derived_key, enum derived_key_type key_type,
 		derived_buf_len = HASH_SIZE;
 
 	derived_buf = kzalloc(derived_buf_len, GFP_KERNEL);
-	if (!derived_buf) {
-		pr_err("encrypted_key: out of memory\n");
+	if (!derived_buf)
 		return -ENOMEM;
-	}
+
 	if (key_type)
 		strcpy(derived_buf, "AUTH_KEY");
 	else
@@ -396,8 +374,8 @@ static int get_derived_key(u8 *derived_key, enum derived_key_type key_type,
 
 	memcpy(derived_buf + strlen(derived_buf) + 1, master_key,
 	       master_keylen);
-	ret = calc_hash(derived_key, derived_buf, derived_buf_len);
-	kfree(derived_buf);
+	ret = calc_hash(hash_tfm, derived_key, derived_buf, derived_buf_len);
+	kzfree(derived_buf);
 	return ret;
 }
 
@@ -480,12 +458,9 @@ static int derived_key_encrypt(struct encrypted_key_payload *epayload,
 	struct skcipher_request *req;
 	unsigned int encrypted_datalen;
 	u8 iv[AES_BLOCK_SIZE];
-	unsigned int padlen;
-	char pad[16];
 	int ret;
 
 	encrypted_datalen = roundup(epayload->decrypted_datalen, blksize);
-	padlen = encrypted_datalen - epayload->decrypted_datalen;
 
 	req = init_skcipher_req(derived_key, derived_keylen);
 	ret = PTR_ERR(req);
@@ -493,11 +468,10 @@ static int derived_key_encrypt(struct encrypted_key_payload *epayload,
 		goto out;
 	dump_decrypted_data(epayload);
 
-	memset(pad, 0, sizeof pad);
 	sg_init_table(sg_in, 2);
 	sg_set_buf(&sg_in[0], epayload->decrypted_data,
 		   epayload->decrypted_datalen);
-	sg_set_buf(&sg_in[1], pad, padlen);
+	sg_set_page(&sg_in[1], ZERO_PAGE(0), AES_BLOCK_SIZE, 0);
 
 	sg_init_table(sg_out, 1);
 	sg_set_buf(sg_out, epayload->encrypted_data, encrypted_datalen);
@@ -533,6 +507,7 @@ static int datablob_hmac_append(struct encrypted_key_payload *epayload,
 	if (!ret)
 		dump_hmac(NULL, digest, HASH_SIZE);
 out:
+	memzero_explicit(derived_key, sizeof(derived_key));
 	return ret;
 }
 
@@ -561,8 +536,8 @@ static int datablob_hmac_verify(struct encrypted_key_payload *epayload,
 	ret = calc_hmac(digest, derived_key, sizeof derived_key, p, len);
 	if (ret < 0)
 		goto out;
-	ret = memcmp(digest, epayload->format + epayload->datablob_len,
-		     sizeof digest);
+	ret = crypto_memneq(digest, epayload->format + epayload->datablob_len,
+			    sizeof(digest));
 	if (ret) {
 		ret = -EINVAL;
 		dump_hmac("datablob",
@@ -571,6 +546,7 @@ static int datablob_hmac_verify(struct encrypted_key_payload *epayload,
 		dump_hmac("calc", digest, HASH_SIZE);
 	}
 out:
+	memzero_explicit(derived_key, sizeof(derived_key));
 	return ret;
 }
 
@@ -584,9 +560,14 @@ static int derived_key_decrypt(struct encrypted_key_payload *epayload,
 	struct skcipher_request *req;
 	unsigned int encrypted_datalen;
 	u8 iv[AES_BLOCK_SIZE];
-	char pad[16];
+	u8 *pad;
 	int ret;
 
+	/* Throwaway buffer to hold the unused zero padding at the end */
+	pad = kmalloc(AES_BLOCK_SIZE, GFP_KERNEL);
+	if (!pad)
+		return -ENOMEM;
+
 	encrypted_datalen = roundup(epayload->decrypted_datalen, blksize);
 	req = init_skcipher_req(derived_key, derived_keylen);
 	ret = PTR_ERR(req);
@@ -594,13 +575,12 @@ static int derived_key_decrypt(struct encrypted_key_payload *epayload,
 		goto out;
 	dump_encrypted_data(epayload, encrypted_datalen);
 
-	memset(pad, 0, sizeof pad);
 	sg_init_table(sg_in, 1);
 	sg_init_table(sg_out, 2);
 	sg_set_buf(sg_in, epayload->encrypted_data, encrypted_datalen);
 	sg_set_buf(&sg_out[0], epayload->decrypted_data,
 		   epayload->decrypted_datalen);
-	sg_set_buf(&sg_out[1], pad, sizeof pad);
+	sg_set_buf(&sg_out[1], pad, AES_BLOCK_SIZE);
 
 	memcpy(iv, epayload->iv, sizeof(iv));
 	skcipher_request_set_crypt(req, sg_in, sg_out, encrypted_datalen, iv);
@@ -612,6 +592,7 @@ static int derived_key_decrypt(struct encrypted_key_payload *epayload,
 		goto out;
 	dump_decrypted_data(epayload);
 out:
+	kfree(pad);
 	return ret;
 }
 
@@ -722,6 +703,7 @@ static int encrypted_key_decrypt(struct encrypted_key_payload *epayload,
 out:
 	up_read(&mkey->sem);
 	key_put(mkey);
+	memzero_explicit(derived_key, sizeof(derived_key));
 	return ret;
 }
 
@@ -828,13 +810,13 @@ static int encrypted_instantiate(struct key *key,
 	ret = encrypted_init(epayload, key->description, format, master_desc,
 			     decrypted_datalen, hex_encoded_iv);
 	if (ret < 0) {
-		kfree(epayload);
+		kzfree(epayload);
 		goto out;
 	}
 
 	rcu_assign_keypointer(key, epayload);
 out:
-	kfree(datablob);
+	kzfree(datablob);
 	return ret;
 }
 
@@ -843,8 +825,7 @@ static void encrypted_rcu_free(struct rcu_head *rcu)
 	struct encrypted_key_payload *epayload;
 
 	epayload = container_of(rcu, struct encrypted_key_payload, rcu);
-	memset(epayload->decrypted_data, 0, epayload->decrypted_datalen);
-	kfree(epayload);
+	kzfree(epayload);
 }
 
 /*
@@ -902,7 +883,7 @@ static int encrypted_update(struct key *key, struct key_preparsed_payload *prep)
 	rcu_assign_keypointer(key, new_epayload);
 	call_rcu(&epayload->rcu, encrypted_rcu_free);
 out:
-	kfree(buf);
+	kzfree(buf);