1 files changed, 337 insertions, 118 deletions

diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 5ecc5057fb5..381411941cc 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -8,7 +8,7 @@
  * as published by the Free Software Foundation; either version
  * 2 of the License, or (at your option) any later version.
  *
- * See Documentation/keys-request-key.txt
+ * See Documentation/security/keys-request-key.txt
  */
 
 #include <linux/module.h>
@@ -16,8 +16,11 @@
 #include <linux/kmod.h>
 #include <linux/err.h>
 #include <linux/keyctl.h>
+#include <linux/slab.h>
 #include "internal.h"
 
+#define key_negative_timeout	60	/* default timeout on a negative key's existence */
+
 /*
  * wait_on_bit() sleep function for uninterruptible waiting
  */
@@ -36,8 +39,14 @@ static int key_wait_bit_intr(void *flags)
 	return signal_pending(current) ? -ERESTARTSYS : 0;
 }
 
-/*
- * call to complete the construction of a key
+/**
+ * complete_request_key - Complete the construction of a key.
+ * @cons: The key construction record.
+ * @error: The success or failute of the construction.
+ *
+ * Complete the attempt to construct a key.  The key will be negated
+ * if an error is indicated.  The authorisation key will be revoked
+ * unconditionally.
  */
 void complete_request_key(struct key_construction *cons, int error)
 {
@@ -56,16 +65,58 @@ void complete_request_key(struct key_construction *cons, int error)
 EXPORT_SYMBOL(complete_request_key);
 
 /*
- * request userspace finish the construction of a key
+ * Initialise a usermode helper that is going to have a specific session
+ * keyring.
+ *
+ * This is called in context of freshly forked kthread before kernel_execve(),
+ * so we can simply install the desired session_keyring at this point.
+ */
+static int umh_keys_init(struct subprocess_info *info, struct cred *cred)
+{
+	struct key *keyring = info->data;
+
+	return install_session_keyring_to_cred(cred, keyring);
+}
+
+/*
+ * Clean up a usermode helper with session keyring.
+ */
+static void umh_keys_cleanup(struct subprocess_info *info)
+{
+	struct key *keyring = info->data;
+	key_put(keyring);
+}
+
+/*
+ * Call a usermode helper with a specific session keyring.
+ */
+static int call_usermodehelper_keys(char *path, char **argv, char **envp,
+					struct key *session_keyring, int wait)
+{
+	struct subprocess_info *info;
+
+	info = call_usermodehelper_setup(path, argv, envp, GFP_KERNEL,
+					  umh_keys_init, umh_keys_cleanup,
+					  session_keyring);
+	if (!info)
+		return -ENOMEM;
+
+	key_get(session_keyring);
+	return call_usermodehelper_exec(info, wait);
+}
+
+/*
+ * Request userspace finish the construction of a key
  * - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring>"
  */
 static int call_sbin_request_key(struct key_construction *cons,
 				 const char *op,
 				 void *aux)
 {
-	struct task_struct *tsk = current;
+	const struct cred *cred = current_cred();
 	key_serial_t prkey, sskey;
-	struct key *key = cons->key, *authkey = cons->authkey, *keyring;
+	struct key *key = cons->key, *authkey = cons->authkey, *keyring,
+		*session;
 	char *argv[9], *envp[3], uid_str[12], gid_str[12];
 	char key_str[12], keyring_str[3][12];
 	char desc[20];
@@ -73,45 +124,50 @@ static int call_sbin_request_key(struct key_construction *cons,
 
 	kenter("{%d},{%d},%s", key->serial, authkey->serial, op);
 
+	ret = install_user_keyrings();
+	if (ret < 0)
+		goto error_alloc;
+
 	/* allocate a new session keyring */
 	sprintf(desc, "_req.%u", key->serial);
 
-	keyring = keyring_alloc(desc, current->fsuid, current->fsgid, current,
+	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);
+	put_cred(cred);
 	if (IS_ERR(keyring)) {
 		ret = PTR_ERR(keyring);
 		goto error_alloc;
 	}
 
 	/* attach the auth key to the session keyring */
-	ret = __key_link(keyring, authkey);
+	ret = key_link(keyring, authkey);
 	if (ret < 0)
 		goto error_link;
 
 	/* record the UID and GID */
-	sprintf(uid_str, "%d", current->fsuid);
-	sprintf(gid_str, "%d", current->fsgid);
+	sprintf(uid_str, "%d", from_kuid(&init_user_ns, cred->fsuid));
+	sprintf(gid_str, "%d", from_kgid(&init_user_ns, cred->fsgid));
 
 	/* we say which key is under construction */
 	sprintf(key_str, "%d", key->serial);
 
 	/* we specify the process's default keyrings */
 	sprintf(keyring_str[0], "%d",
-		tsk->thread_keyring ? tsk->thread_keyring->serial : 0);
+		cred->thread_keyring ? cred->thread_keyring->serial : 0);
 
 	prkey = 0;
-	if (tsk->signal->process_keyring)
-		prkey = tsk->signal->process_keyring->serial;
-
+	if (cred->process_keyring)
+		prkey = cred->process_keyring->serial;
 	sprintf(keyring_str[1], "%d", prkey);
 
-	if (tsk->signal->session_keyring) {
-		rcu_read_lock();
-		sskey = rcu_dereference(tsk->signal->session_keyring)->serial;
-		rcu_read_unlock();
-	} else {
-		sskey = tsk->user->session_keyring->serial;
-	}
+	rcu_read_lock();
+	session = rcu_dereference(cred->session_keyring);
+	if (!session)
+		session = cred->user->session_keyring;
+	sskey = session->serial;
+	rcu_read_unlock();
 
 	sprintf(keyring_str[2], "%d", sskey);
 
@@ -152,30 +208,34 @@ error_link:
 	key_put(keyring);
 
 error_alloc:
-	kleave(" = %d", ret);
 	complete_request_key(cons, ret);
+	kleave(" = %d", ret);
 	return ret;
 }
 
 /*
- * call out to userspace for key construction
- * - we ignore program failure and go on key status instead
+ * Call out to userspace for key construction.
+ *
+ * Program failure is ignored in favour of key status.
  */
-static int construct_key(struct key *key, const char *callout_info, void *aux)
+static int construct_key(struct key *key, const void *callout_info,
+			 size_t callout_len, void *aux,
+			 struct key *dest_keyring)
 {
 	struct key_construction *cons;
 	request_key_actor_t actor;
 	struct key *authkey;
 	int ret;
 
-	kenter("%d,%s,%p", key->serial, callout_info, aux);
+	kenter("%d,%p,%zu,%p", key->serial, callout_info, callout_len, aux);
 
 	cons = kmalloc(sizeof(*cons), GFP_KERNEL);
 	if (!cons)
 		return -ENOMEM;
 
 	/* allocate an authorisation key */
-	authkey = request_key_auth_new(key, callout_info);
+	authkey = request_key_auth_new(key, callout_info, callout_len,
+				       dest_keyring);
 	if (IS_ERR(authkey)) {
 		kfree(cons);
 		ret = PTR_ERR(authkey);
@@ -203,46 +263,68 @@ static int construct_key(struct key *key, const char *callout_info, void *aux)
 }
 
 /*
- * link a key to the appropriate destination keyring
- * - the caller must hold a write lock on the destination keyring
+ * Get the appropriate destination keyring for the request.
+ *
+ * The keyring selected is returned with an extra reference upon it which the
+ * caller must release.
  */
-static void construct_key_make_link(struct key *key, struct key *dest_keyring)
+static void construct_get_dest_keyring(struct key **_dest_keyring)
 {
-	struct task_struct *tsk = current;
-	struct key *drop = NULL;
+	struct request_key_auth *rka;
+	const struct cred *cred = current_cred();
+	struct key *dest_keyring = *_dest_keyring, *authkey;
 
-	kenter("{%d},%p", key->serial, dest_keyring);
+	kenter("%p", dest_keyring);
 
 	/* find the appropriate keyring */
-	if (!dest_keyring) {
-		switch (tsk->jit_keyring) {
+	if (dest_keyring) {
+		/* the caller supplied one */
+		key_get(dest_keyring);
+	} else {
+		/* use a default keyring; falling through the cases until we
+		 * find one that we actually have */
+		switch (cred->jit_keyring) {
 		case KEY_REQKEY_DEFL_DEFAULT:
+		case KEY_REQKEY_DEFL_REQUESTOR_KEYRING:
+			if (cred->request_key_auth) {
+				authkey = cred->request_key_auth;
+				down_read(&authkey->sem);
+				rka = authkey->payload.data;
+				if (!test_bit(KEY_FLAG_REVOKED,
+					      &authkey->flags))
+					dest_keyring =
+						key_get(rka->dest_keyring);
+				up_read(&authkey->sem);
+				if (dest_keyring)
+					break;
+			}
+
 		case KEY_REQKEY_DEFL_THREAD_KEYRING:
-			dest_keyring = tsk->thread_keyring;
+			dest_keyring = key_get(cred->thread_keyring);
 			if (dest_keyring)
 				break;
 
 		case KEY_REQKEY_DEFL_PROCESS_KEYRING:
-			dest_keyring = tsk->signal->process_keyring;
+			dest_keyring = key_get(cred->process_keyring);
 			if (dest_keyring)
 				break;
 
 		case KEY_REQKEY_DEFL_SESSION_KEYRING:
 			rcu_read_lock();
 			dest_keyring = key_get(
-				rcu_dereference(tsk->signal->session_keyring));
+				rcu_dereference(cred->session_keyring));
 			rcu_read_unlock();
-			drop = dest_keyring;
 
 			if (dest_keyring)
 				break;
 
 		case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
-			dest_keyring = tsk->user->session_keyring;
+			dest_keyring =
+				key_get(cred->user->session_keyring);
 			break;
 
 		case KEY_REQKEY_DEFL_USER_KEYRING:
-			dest_keyring = tsk->user->uid_keyring;
+			dest_keyring = key_get(cred->user->uid_keyring);
 			break;
 
 		case KEY_REQKEY_DEFL_GROUP_KEYRING:
@@ -251,86 +333,120 @@ static void construct_key_make_link(struct key *key, struct key *dest_keyring)
 		}
 	}
 
-	/* and attach the key to it */
-	__key_link(dest_keyring, key);
-	key_put(drop);
-	kleave("");
+	*_dest_keyring = dest_keyring;
+	kleave(" [dk %d]", key_serial(dest_keyring));
+	return;
 }
 
 /*
- * allocate a new key in under-construction state and attempt to link it in to
- * the requested place
- * - may return a key that's already under construction instead
+ * Allocate a new key in under-construction state and attempt to link it in to
+ * the requested keyring.
+ *
+ * May return a key that's already under construction instead if there was a
+ * race between two thread calling request_key().
  */
-static int construct_alloc_key(struct key_type *type,
-			       const char *description,
+static int construct_alloc_key(struct keyring_search_context *ctx,
 			       struct key *dest_keyring,
 			       unsigned long flags,
 			       struct key_user *user,
 			       struct key **_key)
 {
+	struct assoc_array_edit *edit;
 	struct key *key;
+	key_perm_t perm;
 	key_ref_t key_ref;
+	int ret;
 
-	kenter("%s,%s,,,", type->name, description);
+	kenter("%s,%s,,,",
+	       ctx->index_key.type->name, ctx->index_key.description);
 
+	*_key = NULL;
 	mutex_lock(&user->cons_lock);
 
-	key = key_alloc(type, description,
-			current->fsuid, current->fsgid, current, KEY_POS_ALL,
-			flags);
+	perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR;
+	perm |= KEY_USR_VIEW;
+	if (ctx->index_key.type->read)
+		perm |= KEY_POS_READ;
+	if (ctx->index_key.type == &key_type_keyring ||
+	    ctx->index_key.type->update)
+		perm |= KEY_POS_WRITE;
+
+	key = key_alloc(ctx->index_key.type, ctx->index_key.description,
+			ctx->cred->fsuid, ctx->cred->fsgid, ctx->cred,
+			perm, flags);
 	if (IS_ERR(key))
 		goto alloc_failed;
 
 	set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags);
 
-	if (dest_keyring)
-		down_write(&dest_keyring->sem);
+	if (dest_keyring) {
+		ret = __key_link_begin(dest_keyring, &ctx->index_key, &edit);
+		if (ret < 0)
+			goto link_prealloc_failed;
+	}
 
 	/* attach the key to the destination keyring under lock, but we do need
 	 * to do another check just in case someone beat us to it whilst we
 	 * waited for locks */
 	mutex_lock(&key_construction_mutex);
 
-	key_ref = search_process_keyrings(type, description, type->match,
-					  current);
+	key_ref = search_process_keyrings(ctx);
 	if (!IS_ERR(key_ref))
 		goto key_already_present;
 
 	if (dest_keyring)
-		construct_key_make_link(key, dest_keyring);
+		__key_link(key, &edit);
 
 	mutex_unlock(&key_construction_mutex);
 	if (dest_keyring)
-		up_write(&dest_keyring->sem);
+		__key_link_end(dest_keyring, &ctx->index_key, edit);
 	mutex_unlock(&user->cons_lock);
 	*_key = key;
 	kleave(" = 0 [%d]", key_serial(key));
 	return 0;
 
+	/* the key is now present - we tell the caller that we found it by
+	 * returning -EINPROGRESS  */
 key_already_present:
+	key_put(key);
 	mutex_unlock(&key_construction_mutex);
-	if (dest_keyring)
-		up_write(&dest_keyring->sem);
+	key = key_ref_to_ptr(key_ref);
+	if (dest_keyring) {
+		ret = __key_link_check_live_key(dest_keyring, key);
+		if (ret == 0)
+			__key_link(key, &edit);
+		__key_link_end(dest_keyring, &ctx->index_key, edit);
+		if (ret < 0)
+			goto link_check_failed;
+	}
 	mutex_unlock(&user->cons_lock);
-	key_put(key);
-	*_key = key = key_ref_to_ptr(key_ref);
+	*_key = key;
 	kleave(" = -EINPROGRESS [%d]", key_serial(key));
 	return -EINPROGRESS;
 
+link_check_failed:
+	mutex_unlock(&user->cons_lock);
+	key_put(key);
+	kleave(" = %d [linkcheck]", ret);
+	return ret;
+
+link_prealloc_failed:
+	mutex_unlock(&user->cons_lock);
+	kleave(" = %d [prelink]", ret);
+	return ret;
+
 alloc_failed:
 	mutex_unlock(&user->cons_lock);
-	*_key = NULL;
 	kleave(" = %ld", PTR_ERR(key));
 	return PTR_ERR(key);
 }
 
 /*
- * commence key construction
+ * Commence key construction.
  */
-static struct key *construct_key_and_link(struct key_type *type,
-					  const char *description,
+static struct key *construct_key_and_link(struct keyring_search_context *ctx,
 					  const char *callout_info,
+					  size_t callout_len,
 					  void *aux,
 					  struct key *dest_keyring,
 					  unsigned long flags)
@@ -339,55 +455,109 @@ static struct key *construct_key_and_link(struct key_type *type,
 	struct key *key;
 	int ret;
 
-	user = key_user_lookup(current->fsuid);
+	kenter("");
+
+	user = key_user_lookup(current_fsuid());
 	if (!user)
 		return ERR_PTR(-ENOMEM);
 
-	ret = construct_alloc_key(type, description, dest_keyring, flags, user,
-				  &key);
+	construct_get_dest_keyring(&dest_keyring);
+
+	ret = construct_alloc_key(ctx, dest_keyring, flags, user, &key);
 	key_user_put(user);
 
 	if (ret == 0) {
-		ret = construct_key(key, callout_info, aux);
-		if (ret < 0)
+		ret = construct_key(key, callout_info, callout_len, aux,
+				    dest_keyring);
+		if (ret < 0) {
+			kdebug("cons failed");
 			goto construction_failed;
+		}
+	} else if (ret == -EINPROGRESS) {
+		ret = 0;
+	} else {
+		goto couldnt_alloc_key;
 	}
 
+	key_put(dest_keyring);
+	kleave(" = key %d", key_serial(key));
 	return key;
 
 construction_failed:
 	key_negate_and_link(key, key_negative_timeout, NULL, NULL);
 	key_put(key);
+couldnt_alloc_key:
+	key_put(dest_keyring);
+	kleave(" = %d", ret);
 	return ERR_PTR(ret);
 }
 
-/*
- * request a key
- * - search the process's keyrings
- * - check the list of keys being created or updated
- * - call out to userspace for a key if supplementary info was provided
- * - cache the key in an appropriate keyring
+/**
+ * request_key_and_link - Request a key and cache it in a keyring.
+ * @type: The type of key we want.
+ * @description: The searchable description of the key.
+ * @callout_info: The data to pass to the instantiation upcall (or NULL).
+ * @callout_len: The length of callout_info.
+ * @aux: Auxiliary data for the upcall.
+ * @dest_keyring: Where to cache the key.
+ * @flags: Flags to key_alloc().
+ *
+ * A key matching the specified criteria is searched for in the process's
+ * keyrings and returned with its usage count incremented if found.  Otherwise,
+ * if callout_info is not NULL, a key will be allocated and some service
+ * (probably in userspace) will be asked to instantiate it.
+ *
+ * If successfully found or created, the key will be linked to the destination
+ * keyring if one is provided.
+ *
+ * Returns a pointer to the key if successful; -EACCES, -ENOKEY, -EKEYREVOKED
+ * or -EKEYEXPIRED if an inaccessible, negative, revoked or expired key was
+ * found; -ENOKEY if no key was found and no @callout_info was given; -EDQUOT
+ * if insufficient key quota was available to create a new key; or -ENOMEM if
+ * insufficient memory was available.
+ *
+ * If the returned key was created, then it may still be under construction,
+ * and wait_for_key_construction() should be used to wait for that to complete.
  */
 struct key *request_key_and_link(struct key_type *type,
 				 const char *description,
-				 const char *callout_info,
+				 const void *callout_info,
+				 size_t callout_len,
 				 void *aux,
 				 struct key *dest_keyring,
 				 unsigned long flags)
 {
+	struct keyring_search_context ctx = {
+		.index_key.type		= type,
+		.index_key.description	= description,
+		.cred			= current_cred(),
+		.match			= type->match,
+		.match_data		= description,
+		.flags			= KEYRING_SEARCH_LOOKUP_DIRECT,
+	};
 	struct key *key;
 	key_ref_t key_ref;
+	int ret;
 
-	kenter("%s,%s,%s,%p,%p,%lx",
-	       type->name, description, callout_info, aux,
-	       dest_keyring, flags);
+	kenter("%s,%s,%p,%zu,%p,%p,%lx",
+	       ctx.index_key.type->name, ctx.index_key.description,
+	       callout_info, callout_len, aux, dest_keyring, flags);
 
 	/* search all the process keyrings for a key */
-	key_ref = search_process_keyrings(type, description, type->match,
-					  current);
+	key_ref = search_process_keyrings(&ctx);
 
 	if (!IS_ERR(key_ref)) {
 		key = key_ref_to_ptr(key_ref);
+		if (dest_keyring) {
+			construct_get_dest_keyring(&dest_keyring);
+			ret = key_link(dest_keyring, key);
+			key_put(dest_keyring);
+			if (ret < 0) {
+				key_put(key);
+				key = ERR_PTR(ret);
+				goto error;
+			}
+		}
 	} else if (PTR_ERR(key_ref) != -EAGAIN) {
 		key = ERR_CAST(key_ref);
 	} else  {
@@ -397,7 +567,7 @@ struct key *request_key_and_link(struct key_type *type,
 		if (!callout_info)
 			goto error;
 
-		key = construct_key_and_link(type, description, callout_info,
+		key = construct_key_and_link(&ctx, callout_info, callout_len,
 					     aux, dest_keyring, flags);
 	}
 
@@ -406,8 +576,16 @@ error:
 	return key;
 }
 
-/*
- * wait for construction of a key to complete
+/**
+ * wait_for_key_construction - Wait for construction of a key to complete
+ * @key: The key being waited for.
+ * @intr: Whether to wait interruptibly.
+ *
+ * Wait for a key to finish being constructed.
+ *
+ * Returns 0 if successful; -ERESTARTSYS if the wait was interrupted; -ENOKEY
+ * if the key was negated; or -EKEYREVOKED or -EKEYEXPIRED if the key was
+ * revoked or expired.
  */
 int wait_for_key_construction(struct key *key, bool intr)
 {
@@ -418,26 +596,40 @@ int wait_for_key_construction(struct key *key, bool intr)
 			  intr ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
 	if (ret < 0)
 		return ret;
+	if (test_bit(KEY_FLAG_NEGATIVE, &key->flags)) {
+		smp_rmb();
+		return key->type_data.reject_error;
+	}
 	return key_validate(key);
 }
 EXPORT_SYMBOL(wait_for_key_construction);
 
-/*
- * request a key
- * - search the process's keyrings
- * - check the list of keys being created or updated
- * - call out to userspace for a key if supplementary info was provided
- * - waits uninterruptible for creation to complete
+/**
+ * request_key - Request a key and wait for construction
+ * @type: Type of key.
+ * @description: The searchable description of the key.
+ * @callout_info: The data to pass to the instantiation upcall (or NULL).
+ *
+ * As for request_key_and_link() except that it does not add the returned key
+ * to a keyring if found, new keys are always allocated in the user's quota,
+ * the callout_info must be a NUL-terminated string and no auxiliary data can
+ * be passed.
+ *
+ * Furthermore, it then works as wait_for_key_construction() to wait for the
+ * completion of keys undergoing construction with a non-interruptible wait.
  */
 struct key *request_key(struct key_type *type,
 			const char *description,
 			const char *callout_info)
 {
 	struct key *key;
+	size_t callout_len = 0;
 	int ret;
 
-	key = request_key_and_link(type, description, callout_info, NULL,
-				   NULL, KEY_ALLOC_IN_QUOTA);
+	if (callout_info)
+		callout_len = strlen(callout_info);
+	key = request_key_and_link(type, description, callout_info, callout_len,
+				   NULL, NULL, KEY_ALLOC_IN_QUOTA);
 	if (!IS_ERR(key)) {
 		ret = wait_for_key_construction(key, false);
 		if (ret < 0) {
@@ -449,23 +641,31 @@ struct key *request_key(struct key_type *type,
 }
 EXPORT_SYMBOL(request_key);
 
-/*
- * request a key with auxiliary data for the upcaller
- * - search the process's keyrings
- * - check the list of keys being created or updated
- * - call out to userspace for a key if supplementary info was provided
- * - waits uninterruptible for creation to complete
+/**
+ * request_key_with_auxdata - Request a key with auxiliary data for the upcaller
+ * @type: The type of key we want.
+ * @description: The searchable description of the key.
+ * @callout_info: The data to pass to the instantiation upcall (or NULL).
+ * @callout_len: The length of callout_info.
+ * @aux: Auxiliary data for the upcall.
+ *
+ * As for request_key_and_link() except that it does not add the returned key
+ * to a keyring if found and new keys are always allocated in the user's quota.
+ *
+ * Furthermore, it then works as wait_for_key_construction() to wait for the
+ * completion of keys undergoing construction with a non-interruptible wait.
  */
 struct key *request_key_with_auxdata(struct key_type *type,
 				     const char *description,
-				     const char *callout_info,
+				     const void *callout_info,
+				     size_t callout_len,
 				     void *aux)
 {
 	struct key *key;
 	int ret;
 
-	key = request_key_and_link(type, description, callout_info, aux,
-				   NULL, KEY_ALLOC_IN_QUOTA);
+	key = request_key_and_link(type, description, callout_info, callout_len,
+				   aux, NULL, KEY_ALLOC_IN_QUOTA);
 	if (!IS_ERR(key)) {
 		ret = wait_for_key_construction(key, false);
 		if (ret < 0) {
@@ -478,32 +678,51 @@ struct key *request_key_with_auxdata(struct key_type *type,
 EXPORT_SYMBOL(request_key_with_auxdata);
 
 /*
- * request a key (allow async construction)
- * - search the process's keyrings
- * - check the list of keys being created or updated
- * - call out to userspace for a key if supplementary info was provided
+ * request_key_async - Request a key (allow async construction)
+ * @type: Type of key.
+ * @description: The searchable description of the key.
+ * @callout_info: The data to pass to the instantiation upcall (or NULL).
+ * @callout_len: The length of callout_info.
+ *
+ * As for request_key_and_link() except that it does not add the returned key
+ * to a keyring if found, new keys are always allocated in the user's quota and
+ * no auxiliary data can be passed.
+ *
+ * The caller should call wait_for_key_construction() to wait for the
+ * completion of the returned key if it is still undergoing construction.
  */
 struct key *request_key_async(struct key_type *type,
 			      const char *description,
-			      const char *callout_info)
+			      const void *callout_info,
+			      size_t callout_len)
 {
-	return request_key_and_link(type, description, callout_info, NULL,
-				    NULL, KEY_ALLOC_IN_QUOTA);
+	return request_key_and_link(type, description, callout_info,
+				    callout_len, NULL, NULL,
+				    KEY_ALLOC_IN_QUOTA);
 }
 EXPORT_SYMBOL(request_key_async);
 
 /*
  * request a key with auxiliary data for the upcaller (allow async construction)
- * - search the process's keyrings
- * - check the list of keys being created or updated
- * - call out to userspace for a key if supplementary info was provided
+ * @type: Type of key.
+ * @description: The searchable description of the key.
+ * @callout_info: The data to pass to the instantiation upcall (or NULL).
+ * @callout_len: The length of callout_info.
+ * @aux: Auxiliary data for the upcall.
+ *
+ * As for request_key_and_link() except that it does not add the returned key
+ * to a keyring if found and new keys are always allocated in the user's quota.
+ *
+ * The caller should call wait_for_key_construction() to wait for the
+ * completion of the returned key if it is still undergoing construction.
  */
 struct key *request_key_async_with_auxdata(struct key_type *type,
 					   const char *description,
-					   const char *callout_info,
+					   const void *callout_info,
+					   size_t callout_len,
 					   void *aux)
 {
-	return request_key_and_link(type, description, callout_info, aux,
-				    NULL, KEY_ALLOC_IN_QUOTA);
+	return request_key_and_link(type, description, callout_info,
+				    callout_len, aux, NULL, KEY_ALLOC_IN_QUOTA);
 }
 EXPORT_SYMBOL(request_key_async_with_auxdata);