1 files changed, 389 insertions, 327 deletions

diff --git a/security/keys/key.c b/security/keys/key.c
index c1eac8084ad..2048a110e7f 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -18,10 +18,9 @@
 #include <linux/workqueue.h>
 #include <linux/random.h>
 #include <linux/err.h>
-#include <linux/user_namespace.h>
 #include "internal.h"
 
-static struct kmem_cache	*key_jar;
+struct kmem_cache *key_jar;
 struct rb_root		key_serial_tree; /* tree of keys indexed by serial */
 DEFINE_SPINLOCK(key_serial_lock);
 
@@ -36,17 +35,9 @@ unsigned int key_quota_maxbytes = 20000;	/* general key space quota */
 static LIST_HEAD(key_types_list);
 static DECLARE_RWSEM(key_types_sem);
 
-static void key_cleanup(struct work_struct *work);
-static DECLARE_WORK(key_cleanup_task, key_cleanup);
-
-/* we serialise key instantiation and link */
+/* We serialise key instantiation and link */
 DEFINE_MUTEX(key_construction_mutex);
 
-/* any key who's type gets unegistered will be re-typed to this */
-static struct key_type key_type_dead = {
-	.name		= "dead",
-};
-
 #ifdef KEY_DEBUGGING
 void __key_check(const struct key *key)
 {
@@ -56,18 +47,17 @@ void __key_check(const struct key *key)
 }
 #endif
 
-/*****************************************************************************/
 /*
- * get the key quota record for a user, allocating a new record if one doesn't
- * already exist
+ * Get the key quota record for a user, allocating a new record if one doesn't
+ * already exist.
  */
-struct key_user *key_user_lookup(uid_t uid, struct user_namespace *user_ns)
+struct key_user *key_user_lookup(kuid_t uid)
 {
 	struct key_user *candidate = NULL, *user;
 	struct rb_node *parent = NULL;
 	struct rb_node **p;
 
- try_again:
+try_again:
 	p = &key_user_tree.rb_node;
 	spin_lock(&key_user_lock);
 
@@ -76,13 +66,9 @@ struct key_user *key_user_lookup(uid_t uid, struct user_namespace *user_ns)
 		parent = *p;
 		user = rb_entry(parent, struct key_user, node);
 
-		if (uid < user->uid)
-			p = &(*p)->rb_left;
-		else if (uid > user->uid)
-			p = &(*p)->rb_right;
-		else if (user_ns < user->user_ns)
+		if (uid_lt(uid, user->uid))
 			p = &(*p)->rb_left;
-		else if (user_ns > user->user_ns)
+		else if (uid_gt(uid, user->uid))
 			p = &(*p)->rb_right;
 		else
 			goto found;
@@ -111,7 +97,6 @@ struct key_user *key_user_lookup(uid_t uid, struct user_namespace *user_ns)
 	atomic_set(&candidate->nkeys, 0);
 	atomic_set(&candidate->nikeys, 0);
 	candidate->uid = uid;
-	candidate->user_ns = get_user_ns(user_ns);
 	candidate->qnkeys = 0;
 	candidate->qnbytes = 0;
 	spin_lock_init(&candidate->lock);
@@ -124,36 +109,30 @@ struct key_user *key_user_lookup(uid_t uid, struct user_namespace *user_ns)
 	goto out;
 
 	/* okay - we found a user record for this UID */
- found:
+found:
 	atomic_inc(&user->usage);
 	spin_unlock(&key_user_lock);
 	kfree(candidate);
- out:
+out:
 	return user;
+}
 
-} /* end key_user_lookup() */
-
-/*****************************************************************************/
 /*
- * dispose of a user structure
+ * Dispose of a user structure
  */
 void key_user_put(struct key_user *user)
 {
 	if (atomic_dec_and_lock(&user->usage, &key_user_lock)) {
 		rb_erase(&user->node, &key_user_tree);
 		spin_unlock(&key_user_lock);
-		put_user_ns(user->user_ns);
 
 		kfree(user);
 	}
+}
 
-} /* end key_user_put() */
-
-/*****************************************************************************/
 /*
- * assign a key the next unique serial number
- * - these are assigned randomly to avoid security issues through covert
- *   channel problems
+ * Allocate a serial number for a key.  These are assigned randomly to avoid
+ * security issues through covert channel problems.
  */
 static inline void key_alloc_serial(struct key *key)
 {
@@ -211,21 +190,39 @@ serial_exists:
 		if (key->serial < xkey->serial)
 			goto attempt_insertion;
 	}
+}
 
-} /* end key_alloc_serial() */
-
-/*****************************************************************************/
-/*
- * allocate a key of the specified type
- * - update the user's quota to reflect the existence of the key
- * - called from a key-type operation with key_types_sem read-locked by
- *   key_create_or_update()
- *   - this prevents unregistration of the key type
- * - upon return the key is as yet uninstantiated; the caller needs to either
- *   instantiate the key or discard it before returning
+/**
+ * key_alloc - Allocate a key of the specified type.
+ * @type: The type of key to allocate.
+ * @desc: The key description to allow the key to be searched out.
+ * @uid: The owner of the new key.
+ * @gid: The group ID for the new key's group permissions.
+ * @cred: The credentials specifying UID namespace.
+ * @perm: The permissions mask of the new key.
+ * @flags: Flags specifying quota properties.
+ *
+ * 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
+ * key before returning.
+ *
+ * The user's key count quota is updated to reflect the creation of the key and
+ * the user's key data quota has the default for the key type reserved.  The
+ * instantiation function should amend this as necessary.  If insufficient
+ * quota is available, -EDQUOT will be returned.
+ *
+ * The LSM security modules can prevent a key being created, in which case
+ * -EACCES will be returned.
+ *
+ * Returns a pointer to the new key if successful and an error code otherwise.
+ *
+ * Note that the caller needs to ensure the key type isn't uninstantiated.
+ * Internally this can be done by locking key_types_sem.  Externally, this can
+ * be done by either never unregistering the key type, or making sure
+ * key_alloc() calls don't race with module unloading.
  */
 struct key *key_alloc(struct key_type *type, const char *desc,
-		      uid_t uid, gid_t gid, const struct cred *cred,
+		      kuid_t uid, kgid_t gid, const struct cred *cred,
 		      key_perm_t perm, unsigned long flags)
 {
 	struct key_user *user = NULL;
@@ -237,20 +234,28 @@ struct key *key_alloc(struct key_type *type, const char *desc,
 	if (!desc || !*desc)
 		goto error;
 
-	desclen = strlen(desc) + 1;
-	quotalen = desclen + type->def_datalen;
+	if (type->vet_description) {
+		ret = type->vet_description(desc);
+		if (ret < 0) {
+			key = ERR_PTR(ret);
+			goto error;
+		}
+	}
+
+	desclen = strlen(desc);
+	quotalen = desclen + 1 + type->def_datalen;
 
 	/* get hold of the key tracking for this user */
-	user = key_user_lookup(uid, cred->user->user_ns);
+	user = key_user_lookup(uid);
 	if (!user)
 		goto no_memory_1;
 
 	/* check that the user's quota permits allocation of another key and
 	 * its description */
 	if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) {
-		unsigned maxkeys = (uid == 0) ?
+		unsigned maxkeys = uid_eq(uid, GLOBAL_ROOT_UID) ?
 			key_quota_root_maxkeys : key_quota_maxkeys;
-		unsigned maxbytes = (uid == 0) ?
+		unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ?
 			key_quota_root_maxbytes : key_quota_maxbytes;
 
 		spin_lock(&user->lock);
@@ -267,34 +272,32 @@ struct key *key_alloc(struct key_type *type, const char *desc,
 	}
 
 	/* allocate and initialise the key and its description */
-	key = kmem_cache_alloc(key_jar, GFP_KERNEL);
+	key = kmem_cache_zalloc(key_jar, GFP_KERNEL);
 	if (!key)
 		goto no_memory_2;
 
 	if (desc) {
-		key->description = kmemdup(desc, desclen, GFP_KERNEL);
+		key->index_key.desc_len = desclen;
+		key->index_key.description = kmemdup(desc, desclen + 1, GFP_KERNEL);
 		if (!key->description)
 			goto no_memory_3;
 	}
 
 	atomic_set(&key->usage, 1);
 	init_rwsem(&key->sem);
-	key->type = type;
+	lockdep_set_class(&key->sem, &type->lock_class);
+	key->index_key.type = type;
 	key->user = user;
 	key->quotalen = quotalen;
 	key->datalen = type->def_datalen;
 	key->uid = uid;
 	key->gid = gid;
 	key->perm = perm;
-	key->flags = 0;
-	key->expiry = 0;
-	key->payload.data = NULL;
-	key->security = NULL;
 
 	if (!(flags & KEY_ALLOC_NOT_IN_QUOTA))
 		key->flags |= 1 << KEY_FLAG_IN_QUOTA;
-
-	memset(&key->type_data, 0, sizeof(key->type_data));
+	if (flags & KEY_ALLOC_TRUSTED)
+		key->flags |= 1 << KEY_FLAG_TRUSTED;
 
 #ifdef KEY_DEBUGGING
 	key->magic = KEY_DEBUG_MAGIC;
@@ -344,14 +347,19 @@ no_quota:
 	key_user_put(user);
 	key = ERR_PTR(-EDQUOT);
 	goto error;
-
-} /* end key_alloc() */
-
+}
 EXPORT_SYMBOL(key_alloc);
 
-/*****************************************************************************/
-/*
- * reserve an amount of quota for the key's payload
+/**
+ * key_payload_reserve - Adjust data quota reservation for the key's payload
+ * @key: The key to make the reservation for.
+ * @datalen: The amount of data payload the caller now wants.
+ *
+ * Adjust the amount of the owning user's key data quota that a key reserves.
+ * If the amount is increased, then -EDQUOT may be returned if there isn't
+ * enough free quota available.
+ *
+ * If successful, 0 is returned.
  */
 int key_payload_reserve(struct key *key, size_t datalen)
 {
@@ -362,7 +370,7 @@ int key_payload_reserve(struct key *key, size_t datalen)
 
 	/* contemplate the quota adjustment */
 	if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) {
-		unsigned maxbytes = (key->user->uid == 0) ?
+		unsigned maxbytes = uid_eq(key->user->uid, GLOBAL_ROOT_UID) ?
 			key_quota_root_maxbytes : key_quota_maxbytes;
 
 		spin_lock(&key->user->lock);
@@ -384,22 +392,20 @@ int key_payload_reserve(struct key *key, size_t datalen)
 		key->datalen = datalen;
 
 	return ret;
-
-} /* end key_payload_reserve() */
-
+}
 EXPORT_SYMBOL(key_payload_reserve);
 
-/*****************************************************************************/
 /*
- * instantiate a key and link it into the target keyring atomically
- * - called with the target keyring's semaphore writelocked
+ * Instantiate a key and link it into the target keyring atomically.  Must be
+ * called with the target keyring's semaphore writelocked.  The target key's
+ * semaphore need not be locked as instantiation is serialised by
+ * key_construction_mutex.
  */
 static int __key_instantiate_and_link(struct key *key,
-				      const void *data,
-				      size_t datalen,
+				      struct key_preparsed_payload *prep,
 				      struct key *keyring,
 				      struct key *authkey,
-				      struct keyring_list **_prealloc)
+				      struct assoc_array_edit **_edit)
 {
 	int ret, awaken;
 
@@ -414,7 +420,7 @@ static int __key_instantiate_and_link(struct key *key,
 	/* can't instantiate twice */
 	if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
 		/* instantiate the key */
-		ret = key->type->instantiate(key, data, datalen);
+		ret = key->type->instantiate(key, prep);
 
 		if (ret == 0) {
 			/* mark the key as being instantiated */
@@ -426,7 +432,7 @@ static int __key_instantiate_and_link(struct key *key,
 
 			/* and link it into the destination keyring */
 			if (keyring)
-				__key_link(keyring, key, _prealloc);
+				__key_link(key, _edit);
 
 			/* disable the authorisation key */
 			if (authkey)
@@ -441,12 +447,23 @@ static int __key_instantiate_and_link(struct key *key,
 		wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT);
 
 	return ret;
+}
 
-} /* end __key_instantiate_and_link() */
-
-/*****************************************************************************/
-/*
- * instantiate a key and link it into the target keyring atomically
+/**
+ * key_instantiate_and_link - Instantiate a key and link it into the keyring.
+ * @key: The key to instantiate.
+ * @data: The data to use to instantiate the keyring.
+ * @datalen: The length of @data.
+ * @keyring: Keyring to create a link in on success (or NULL).
+ * @authkey: The authorisation token permitting instantiation.
+ *
+ * Instantiate a key that's in the uninstantiated state using the provided data
+ * and, if successful, link it in to the destination keyring if one is
+ * supplied.
+ *
+ * If successful, 0 is returned, the authorisation token is revoked and anyone
+ * waiting for the key is woken up.  If the key was already instantiated,
+ * -EBUSY will be returned.
  */
 int key_instantiate_and_link(struct key *key,
 			     const void *data,
@@ -454,38 +471,68 @@ int key_instantiate_and_link(struct key *key,
 			     struct key *keyring,
 			     struct key *authkey)
 {
-	struct keyring_list *prealloc;
+	struct key_preparsed_payload prep;
+	struct assoc_array_edit *edit;
 	int ret;
 
+	memset(&prep, 0, sizeof(prep));
+	prep.data = data;
+	prep.datalen = datalen;
+	prep.quotalen = key->type->def_datalen;
+	if (key->type->preparse) {
+		ret = key->type->preparse(&prep);
+		if (ret < 0)
+			goto error;
+	}
+
 	if (keyring) {
-		ret = __key_link_begin(keyring, key->type, key->description,
-				       &prealloc);
+		ret = __key_link_begin(keyring, &key->index_key, &edit);
 		if (ret < 0)
-			return ret;
+			goto error_free_preparse;
 	}
 
-	ret = __key_instantiate_and_link(key, data, datalen, keyring, authkey,
-					 &prealloc);
+	ret = __key_instantiate_and_link(key, &prep, keyring, authkey, &edit);
 
 	if (keyring)
-		__key_link_end(keyring, key->type, prealloc);
+		__key_link_end(keyring, &key->index_key, edit);
 
+error_free_preparse:
+	if (key->type->preparse)
+		key->type->free_preparse(&prep);
+error:
 	return ret;
-
-} /* end key_instantiate_and_link() */
+}
 
 EXPORT_SYMBOL(key_instantiate_and_link);
 
-/*****************************************************************************/
-/*
- * negatively instantiate a key and link it into the target keyring atomically
+/**
+ * key_reject_and_link - Negatively instantiate a key and link it into the keyring.
+ * @key: The key to instantiate.
+ * @timeout: The timeout on the negative key.
+ * @error: The error to return when the key is hit.
+ * @keyring: Keyring to create a link in on success (or NULL).
+ * @authkey: The authorisation token permitting instantiation.
+ *
+ * Negatively instantiate a key that's in the uninstantiated state and, if
+ * successful, set its timeout and stored error and link it in to the
+ * destination keyring if one is supplied.  The key and any links to the key
+ * will be automatically garbage collected after the timeout expires.
+ *
+ * Negative keys are used to rate limit repeated request_key() calls by causing
+ * them to return the stored error code (typically ENOKEY) until the negative
+ * key expires.
+ *
+ * If successful, 0 is returned, the authorisation token is revoked and anyone
+ * waiting for the key is woken up.  If the key was already instantiated,
+ * -EBUSY will be returned.
  */
-int key_negate_and_link(struct key *key,
+int key_reject_and_link(struct key *key,
 			unsigned timeout,
+			unsigned error,
 			struct key *keyring,
 			struct key *authkey)
 {
-	struct keyring_list *prealloc;
+	struct assoc_array_edit *edit;
 	struct timespec now;
 	int ret, awaken, link_ret = 0;
 
@@ -496,8 +543,7 @@ int key_negate_and_link(struct key *key,
 	ret = -EBUSY;
 
 	if (keyring)
-		link_ret = __key_link_begin(keyring, key->type,
-					    key->description, &prealloc);
+		link_ret = __key_link_begin(keyring, &key->index_key, &edit);
 
 	mutex_lock(&key_construction_mutex);
 
@@ -505,6 +551,8 @@ int key_negate_and_link(struct key *key,
 	if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
 		/* mark the key as being negatively instantiated */
 		atomic_inc(&key->user->nikeys);
+		key->type_data.reject_error = -error;
+		smp_wmb();
 		set_bit(KEY_FLAG_NEGATIVE, &key->flags);
 		set_bit(KEY_FLAG_INSTANTIATED, &key->flags);
 		now = current_kernel_time();
@@ -518,7 +566,7 @@ int key_negate_and_link(struct key *key,
 
 		/* and link it into the destination keyring */
 		if (keyring && link_ret == 0)
-			__key_link(keyring, key, &prealloc);
+			__key_link(key, &edit);
 
 		/* disable the authorisation key */
 		if (authkey)
@@ -528,87 +576,23 @@ int key_negate_and_link(struct key *key,
 	mutex_unlock(&key_construction_mutex);
 
 	if (keyring)
-		__key_link_end(keyring, key->type, prealloc);
+		__key_link_end(keyring, &key->index_key, edit);
 
 	/* wake up anyone waiting for a key to be constructed */
 	if (awaken)
 		wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT);
 
 	return ret == 0 ? link_ret : ret;
+}
+EXPORT_SYMBOL(key_reject_and_link);
 
-} /* end key_negate_and_link() */
-
-EXPORT_SYMBOL(key_negate_and_link);
-
-/*****************************************************************************/
-/*
- * do cleaning up in process context so that we don't have to disable
- * interrupts all over the place
- */
-static void key_cleanup(struct work_struct *work)
-{
-	struct rb_node *_n;
-	struct key *key;
-
- go_again:
-	/* look for a dead key in the tree */
-	spin_lock(&key_serial_lock);
-
-	for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) {
-		key = rb_entry(_n, struct key, serial_node);
-
-		if (atomic_read(&key->usage) == 0)
-			goto found_dead_key;
-	}
-
-	spin_unlock(&key_serial_lock);
-	return;
-
- found_dead_key:
-	/* we found a dead key - once we've removed it from the tree, we can
-	 * drop the lock */
-	rb_erase(&key->serial_node, &key_serial_tree);
-	spin_unlock(&key_serial_lock);
-
-	key_check(key);
-
-	security_key_free(key);
-
-	/* deal with the user's key tracking and quota */
-	if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) {
-		spin_lock(&key->user->lock);
-		key->user->qnkeys--;
-		key->user->qnbytes -= key->quotalen;
-		spin_unlock(&key->user->lock);
-	}
-
-	atomic_dec(&key->user->nkeys);
-	if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags))
-		atomic_dec(&key->user->nikeys);
-
-	key_user_put(key->user);
-
-	/* now throw away the key memory */
-	if (key->type->destroy)
-		key->type->destroy(key);
-
-	kfree(key->description);
-
-#ifdef KEY_DEBUGGING
-	key->magic = KEY_DEBUG_MAGIC_X;
-#endif
-	kmem_cache_free(key_jar, key);
-
-	/* there may, of course, be more than one key to destroy */
-	goto go_again;
-
-} /* end key_cleanup() */
-
-/*****************************************************************************/
-/*
- * dispose of a reference to a key
- * - when all the references are gone, we schedule the cleanup task to come and
- *   pull it out of the tree in definite process context
+/**
+ * key_put - Discard a reference to a key.
+ * @key: The key to discard a reference from.
+ *
+ * Discard a reference to a key, and when all the references are gone, we
+ * schedule the cleanup task to come and pull it out of the tree in process
+ * context at some later time.
  */
 void key_put(struct key *key)
 {
@@ -616,16 +600,13 @@ void key_put(struct key *key)
 		key_check(key);
 
 		if (atomic_dec_and_test(&key->usage))
-			schedule_work(&key_cleanup_task);
+			schedule_work(&key_gc_work);
 	}
-
-} /* end key_put() */
-
+}
 EXPORT_SYMBOL(key_put);
 
-/*****************************************************************************/
 /*
- * find a key by its serial number
+ * Find a key by its serial number.
  */
 struct key *key_lookup(key_serial_t id)
 {
@@ -647,11 +628,11 @@ struct key *key_lookup(key_serial_t id)
 			goto found;
 	}
 
- not_found:
+not_found:
 	key = ERR_PTR(-ENOKEY);
 	goto error;
 
- found:
+found:
 	/* pretend it doesn't exist if it is awaiting deletion */
 	if (atomic_read(&key->usage) == 0)
 		goto not_found;
@@ -659,18 +640,18 @@ struct key *key_lookup(key_serial_t id)
 	/* this races with key_put(), but that doesn't matter since key_put()
 	 * doesn't actually change the key
 	 */
-	atomic_inc(&key->usage);
+	__key_get(key);
 
- error:
+error:
 	spin_unlock(&key_serial_lock);
 	return key;
+}
 
-} /* end key_lookup() */
-
-/*****************************************************************************/
 /*
- * find and lock the specified key type against removal
- * - we return with the sem readlocked
+ * Find and lock the specified key type against removal.
+ *
+ * We return with the sem read-locked if successful.  If the type wasn't
+ * available -ENOKEY is returned instead.
  */
 struct key_type *key_type_lookup(const char *type)
 {
@@ -688,35 +669,52 @@ struct key_type *key_type_lookup(const char *type)
 	up_read(&key_types_sem);
 	ktype = ERR_PTR(-ENOKEY);
 
- found_kernel_type:
+found_kernel_type:
 	return ktype;
+}
+
+void key_set_timeout(struct key *key, unsigned timeout)
+{
+	struct timespec now;
+	time_t expiry = 0;
+
+	/* make the changes with the locks held to prevent races */
+	down_write(&key->sem);
 
-} /* end key_type_lookup() */
+	if (timeout > 0) {
+		now = current_kernel_time();
+		expiry = now.tv_sec + timeout;
+	}
+
+	key->expiry = expiry;
+	key_schedule_gc(key->expiry + key_gc_delay);
+
+	up_write(&key->sem);
+}
+EXPORT_SYMBOL_GPL(key_set_timeout);
 
-/*****************************************************************************/
 /*
- * unlock a key type
+ * Unlock a key type locked by key_type_lookup().
  */
 void key_type_put(struct key_type *ktype)
 {
 	up_read(&key_types_sem);
+}
 
-} /* end key_type_put() */
-
-/*****************************************************************************/
 /*
- * attempt to update an existing key
- * - the key has an incremented refcount
- * - we need to put the key if we get an error
+ * Attempt to update an existing key.
+ *
+ * The key is given to us with an incremented refcount that we need to discard
+ * if we get an error.
  */
 static inline key_ref_t __key_update(key_ref_t key_ref,
-				     const void *payload, size_t plen)
+				     struct key_preparsed_payload *prep)
 {
 	struct key *key = key_ref_to_ptr(key_ref);
 	int ret;
 
 	/* need write permission on the key to update it */
-	ret = key_permission(key_ref, KEY_WRITE);
+	ret = key_permission(key_ref, KEY_NEED_WRITE);
 	if (ret < 0)
 		goto error;
 
@@ -726,7 +724,7 @@ static inline key_ref_t __key_update(key_ref_t key_ref,
 
 	down_write(&key->sem);
 
-	ret = key->type->update(key, payload, plen);
+	ret = key->type->update(key, prep);
 	if (ret == 0)
 		/* updating a negative key instantiates it */
 		clear_bit(KEY_FLAG_NEGATIVE, &key->flags);
@@ -742,13 +740,32 @@ error:
 	key_put(key);
 	key_ref = ERR_PTR(ret);
 	goto out;
+}
 
-} /* end __key_update() */
-
-/*****************************************************************************/
-/*
- * search the specified keyring for a key of the same description; if one is
- * found, update it, otherwise add a new one
+/**
+ * key_create_or_update - Update or create and instantiate a key.
+ * @keyring_ref: A pointer to the destination keyring with possession flag.
+ * @type: The type of key.
+ * @description: The searchable description for the key.
+ * @payload: The data to use to instantiate or update the key.
+ * @plen: The length of @payload.
+ * @perm: The permissions mask for a new key.
+ * @flags: The quota flags for a new key.
+ *
+ * Search the destination keyring for a key of the same description and if one
+ * is found, update it, otherwise create and instantiate a new one and create a
+ * link to it from that keyring.
+ *
+ * If perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be
+ * concocted.
+ *
+ * Returns a pointer to the new key if successful, -ENODEV if the key type
+ * wasn't available, -ENOTDIR if the keyring wasn't a keyring, -EACCES if the
+ * caller isn't permitted to modify the keyring or the LSM did not permit
+ * creation of the key.
+ *
+ * On success, the possession flag from the keyring ref will be tacked on to
+ * the key ref before it is returned.
  */
 key_ref_t key_create_or_update(key_ref_t keyring_ref,
 			       const char *type,
@@ -758,24 +775,28 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
 			       key_perm_t perm,
 			       unsigned long flags)
 {
-	struct keyring_list *prealloc;
+	struct keyring_index_key index_key = {
+		.description	= description,
+	};
+	struct key_preparsed_payload prep;
+	struct assoc_array_edit *edit;
 	const struct cred *cred = current_cred();
-	struct key_type *ktype;
 	struct key *keyring, *key = NULL;
 	key_ref_t key_ref;
 	int ret;
 
 	/* look up the key type to see if it's one of the registered kernel
 	 * types */
-	ktype = key_type_lookup(type);
-	if (IS_ERR(ktype)) {
+	index_key.type = key_type_lookup(type);
+	if (IS_ERR(index_key.type)) {
 		key_ref = ERR_PTR(-ENODEV);
 		goto error;
 	}
 
 	key_ref = ERR_PTR(-EINVAL);
-	if (!ktype->match || !ktype->instantiate)
-		goto error_2;
+	if (!index_key.type->match || !index_key.type->instantiate ||
+	    (!index_key.description && !index_key.type->preparse))
+		goto error_put_type;
 
 	keyring = key_ref_to_ptr(keyring_ref);
 
@@ -783,122 +804,173 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
 
 	key_ref = ERR_PTR(-ENOTDIR);
 	if (keyring->type != &key_type_keyring)
-		goto error_2;
+		goto error_put_type;
+
+	memset(&prep, 0, sizeof(prep));
+	prep.data = payload;
+	prep.datalen = plen;
+	prep.quotalen = index_key.type->def_datalen;
+	prep.trusted = flags & KEY_ALLOC_TRUSTED;
+	if (index_key.type->preparse) {
+		ret = index_key.type->preparse(&prep);
+		if (ret < 0) {
+			key_ref = ERR_PTR(ret);
+			goto error_put_type;
+		}
+		if (!index_key.description)
+			index_key.description = prep.description;
+		key_ref = ERR_PTR(-EINVAL);
+		if (!index_key.description)
+			goto error_free_prep;
+	}
+	index_key.desc_len = strlen(index_key.description);
 
-	ret = __key_link_begin(keyring, ktype, description, &prealloc);
-	if (ret < 0)
-		goto error_2;
+	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;
+
+	ret = __key_link_begin(keyring, &index_key, &edit);
+	if (ret < 0) {
+		key_ref = ERR_PTR(ret);
+		goto error_free_prep;
+	}
 
 	/* if we're going to allocate a new key, we're going to have
 	 * to modify the keyring */
-	ret = key_permission(keyring_ref, KEY_WRITE);
+	ret = key_permission(keyring_ref, KEY_NEED_WRITE);
 	if (ret < 0) {
 		key_ref = ERR_PTR(ret);
-		goto error_3;
+		goto error_link_end;
 	}
 
 	/* if it's possible to update this type of key, search for an existing
 	 * key of the same type and description in the destination keyring and
 	 * update that instead if possible
 	 */
-	if (ktype->update) {
-		key_ref = __keyring_search_one(keyring_ref, ktype, description,
-					       0);
-		if (!IS_ERR(key_ref))
+	if (index_key.type->update) {
+		key_ref = find_key_to_update(keyring_ref, &index_key);
+		if (key_ref)
 			goto found_matching_key;
 	}
 
 	/* if the client doesn't provide, decide on the permissions we want */
 	if (perm == KEY_PERM_UNDEF) {
 		perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR;
-		perm |= KEY_USR_VIEW | KEY_USR_SEARCH | KEY_USR_LINK | KEY_USR_SETATTR;
+		perm |= KEY_USR_VIEW;
 
-		if (ktype->read)
-			perm |= KEY_POS_READ | KEY_USR_READ;
+		if (index_key.type->read)
+			perm |= KEY_POS_READ;
 
-		if (ktype == &key_type_keyring || ktype->update)
-			perm |= KEY_USR_WRITE;
+		if (index_key.type == &key_type_keyring ||
+		    index_key.type->update)
+			perm |= KEY_POS_WRITE;
 	}
 
 	/* allocate a new key */
-	key = key_alloc(ktype, description, cred->fsuid, cred->fsgid, cred,
-			perm, flags);
+	key = key_alloc(index_key.type, index_key.description,
+			cred->fsuid, cred->fsgid, cred, perm, flags);
 	if (IS_ERR(key)) {
 		key_ref = ERR_CAST(key);
-		goto error_3;
+		goto error_link_end;
 	}
 
 	/* instantiate it and link it into the target keyring */
-	ret = __key_instantiate_and_link(key, payload, plen, keyring, NULL,
-					 &prealloc);
+	ret = __key_instantiate_and_link(key, &prep, keyring, NULL, &edit);
 	if (ret < 0) {
 		key_put(key);
 		key_ref = ERR_PTR(ret);
-		goto error_3;
+		goto error_link_end;
 	}
 
 	key_ref = make_key_ref(key, is_key_possessed(keyring_ref));
 
- error_3:
-	__key_link_end(keyring, ktype, prealloc);
- error_2:
-	key_type_put(ktype);
- error:
+error_link_end:
+	__key_link_end(keyring, &index_key, edit);
+error_free_prep:
+	if (index_key.type->preparse)
+		index_key.type->free_preparse(&prep);
+error_put_type:
+	key_type_put(index_key.type);
+error:
 	return key_ref;
 
  found_matching_key:
 	/* we found a matching key, so we're going to try to update it
 	 * - we can drop the locks first as we have the key pinned
 	 */
-	__key_link_end(keyring, ktype, prealloc);
-	key_type_put(ktype);
-
-	key_ref = __key_update(key_ref, payload, plen);
-	goto error;
-
-} /* end key_create_or_update() */
+	__key_link_end(keyring, &index_key, edit);
 
+	key_ref = __key_update(key_ref, &prep);
+	goto error_free_prep;
+}
 EXPORT_SYMBOL(key_create_or_update);
 
-/*****************************************************************************/
-/*
- * update a key
+/**
+ * key_update - Update a key's contents.
+ * @key_ref: The pointer (plus possession flag) to the key.
+ * @payload: The data to be used to update the key.
+ * @plen: The length of @payload.
+ *
+ * Attempt to update the contents of a key with the given payload data.  The
+ * caller must be granted Write permission on the key.  Negative keys can be
+ * instantiated by this method.
+ *
+ * Returns 0 on success, -EACCES if not permitted and -EOPNOTSUPP if the key
+ * type does not support updating.  The key type may return other errors.
  */
 int key_update(key_ref_t key_ref, const void *payload, size_t plen)
 {
+	struct key_preparsed_payload prep;
 	struct key *key = key_ref_to_ptr(key_ref);
 	int ret;
 
 	key_check(key);
 
 	/* the key must be writable */
-	ret = key_permission(key_ref, KEY_WRITE);
+	ret = key_permission(key_ref, KEY_NEED_WRITE);
 	if (ret < 0)
 		goto error;
 
 	/* attempt to update it if supported */
 	ret = -EOPNOTSUPP;
-	if (key->type->update) {
-		down_write(&key->sem);
-
-		ret = key->type->update(key, payload, plen);
-		if (ret == 0)
-			/* updating a negative key instantiates it */
-			clear_bit(KEY_FLAG_NEGATIVE, &key->flags);
+	if (!key->type->update)
+		goto error;
 
-		up_write(&key->sem);
+	memset(&prep, 0, sizeof(prep));
+	prep.data = payload;
+	prep.datalen = plen;
+	prep.quotalen = key->type->def_datalen;
+	if (key->type->preparse) {
+		ret = key->type->preparse(&prep);
+		if (ret < 0)
+			goto error;
 	}
 
- error:
-	return ret;
+	down_write(&key->sem);
 
-} /* end key_update() */
+	ret = key->type->update(key, &prep);
+	if (ret == 0)
+		/* updating a negative key instantiates it */
+		clear_bit(KEY_FLAG_NEGATIVE, &key->flags);
 
+	up_write(&key->sem);
+
+	if (key->type->preparse)
+		key->type->free_preparse(&prep);
+error:
+	return ret;
+}
 EXPORT_SYMBOL(key_update);
 
-/*****************************************************************************/
-/*
- * revoke a key
+/**
+ * key_revoke - Revoke a key.
+ * @key: The key to be revoked.
+ *
+ * Mark a key as being revoked and ask the type to free up its resources.  The
+ * revocation timeout is set and the key and all its links will be
+ * automatically garbage collected after key_gc_delay amount of time if they
+ * are not manually dealt with first.
  */
 void key_revoke(struct key *key)
 {
@@ -926,20 +998,46 @@ void key_revoke(struct key *key)
 	}
 
 	up_write(&key->sem);
+}
+EXPORT_SYMBOL(key_revoke);
 
-} /* end key_revoke() */
+/**
+ * key_invalidate - Invalidate a key.
+ * @key: The key to be invalidated.
+ *
+ * Mark a key as being invalidated and have it cleaned up immediately.  The key
+ * is ignored by all searches and other operations from this point.
+ */
+void key_invalidate(struct key *key)
+{
+	kenter("%d", key_serial(key));
 
-EXPORT_SYMBOL(key_revoke);
+	key_check(key);
 
-/*****************************************************************************/
-/*
- * register a type of key
+	if (!test_bit(KEY_FLAG_INVALIDATED, &key->flags)) {
+		down_write_nested(&key->sem, 1);
+		if (!test_and_set_bit(KEY_FLAG_INVALIDATED, &key->flags))
+			key_schedule_gc_links();
+		up_write(&key->sem);
+	}
+}
+EXPORT_SYMBOL(key_invalidate);
+
+/**
+ * register_key_type - Register a type of key.
+ * @ktype: The new key type.
+ *
+ * Register a new key type.
+ *
+ * Returns 0 on success or -EEXIST if a type of this name already exists.
  */
 int register_key_type(struct key_type *ktype)
 {
 	struct key_type *p;
 	int ret;
 
+	memset(&ktype->lock_class, 0, sizeof(ktype->lock_class));
+
 	ret = -EEXIST;
 	down_write(&key_types_sem);
 
@@ -951,73 +1049,37 @@ int register_key_type(struct key_type *ktype)
 
 	/* store the type */
 	list_add(&ktype->link, &key_types_list);
+
+	pr_notice("Key type %s registered\n", ktype->name);
 	ret = 0;
 
- out:
+out:
 	up_write(&key_types_sem);
 	return ret;
-
-} /* end register_key_type() */
-
+}
 EXPORT_SYMBOL(register_key_type);
 
-/*****************************************************************************/
-/*
- * unregister a type of key
+/**
+ * unregister_key_type - Unregister a type of key.
+ * @ktype: The key type.
+ *
+ * Unregister a key type and mark all the extant keys of this type as dead.
+ * Those keys of this type are then destroyed to get rid of their payloads and
+ * they and their links will be garbage collected as soon as possible.
  */
 void unregister_key_type(struct key_type *ktype)
 {
-	struct rb_node *_n;
-	struct key *key;
-
 	down_write(&key_types_sem);
-
-	/* withdraw the key type */
 	list_del_init(&ktype->link);
-
-	/* mark all the keys of this type dead */
-	spin_lock(&key_serial_lock);
-
-	for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) {
-		key = rb_entry(_n, struct key, serial_node);
-
-		if (key->type == ktype) {
-			key->type = &key_type_dead;
-			set_bit(KEY_FLAG_DEAD, &key->flags);
-		}
-	}
-
-	spin_unlock(&key_serial_lock);
-
-	/* make sure everyone revalidates their keys */
-	synchronize_rcu();
-
-	/* we should now be able to destroy the payloads of all the keys of
-	 * this type with impunity */
-	spin_lock(&key_serial_lock);
-
-	for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) {
-		key = rb_entry(_n, struct key, serial_node);
-
-		if (key->type == ktype) {
-			if (ktype->destroy)
-				ktype->destroy(key);
-			memset(&key->payload, KEY_DESTROY, sizeof(key->payload));
-		}
-	}
-
-	spin_unlock(&key_serial_lock);
-	up_write(&key_types_sem);
-
-	key_schedule_gc(0);
-
-} /* end unregister_key_type() */
-
+	downgrade_write(&key_types_sem);
+	key_gc_keytype(ktype);
+	pr_notice("Key type %s unregistered\n", ktype->name);
+	up_read(&key_types_sem);
+}
 EXPORT_SYMBOL(unregister_key_type);
 
-/*****************************************************************************/
 /*
- * initialise the key management stuff
+ * Initialise the key management state.
  */
 void __init key_init(void)
 {
@@ -1029,6 +1091,7 @@ void __init key_init(void)
 	list_add_tail(&key_type_keyring.link, &key_types_list);
 	list_add_tail(&key_type_dead.link, &key_types_list);
 	list_add_tail(&key_type_user.link, &key_types_list);
+	list_add_tail(&key_type_logon.link, &key_types_list);
 
 	/* record the root user tracking */
 	rb_link_node(&root_key_user.node,
@@ -1037,5 +1100,4 @@ void __init key_init(void)
 
 	rb_insert_color(&root_key_user.node,
 			&key_user_tree);
-
-} /* end key_init() */
+}