1 files changed, 59 insertions, 82 deletions

diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c
index 55dc88939185..686d56e4cc85 100644
--- a/security/keys/user_defined.c
+++ b/security/keys/user_defined.c
@@ -1,21 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /* user_defined.c: user defined key type
  *
  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
  */
 
-#include <linux/module.h>
+#include <linux/export.h>
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/seq_file.h>
 #include <linux/err.h>
 #include <keys/user-type.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
 #include "internal.h"
 
 static int logon_vet_description(const char *desc);
@@ -25,14 +21,15 @@ static int logon_vet_description(const char *desc);
  * arbitrary blob of data as the payload
  */
 struct key_type key_type_user = {
-	.name		= "user",
-	.instantiate	= user_instantiate,
-	.update		= user_update,
-	.match		= user_match,
-	.revoke		= user_revoke,
-	.destroy	= user_destroy,
-	.describe	= user_describe,
-	.read		= user_read,
+	.name			= "user",
+	.preparse		= user_preparse,
+	.free_preparse		= user_free_preparse,
+	.instantiate		= generic_key_instantiate,
+	.update			= user_update,
+	.revoke			= user_revoke,
+	.destroy		= user_destroy,
+	.describe		= user_describe,
+	.read			= user_read,
 };
 
 EXPORT_SYMBOL_GPL(key_type_user);
@@ -45,9 +42,10 @@ EXPORT_SYMBOL_GPL(key_type_user);
  */
 struct key_type key_type_logon = {
 	.name			= "logon",
-	.instantiate		= user_instantiate,
+	.preparse		= user_preparse,
+	.free_preparse		= user_free_preparse,
+	.instantiate		= generic_key_instantiate,
 	.update			= user_update,
-	.match			= user_match,
 	.revoke			= user_revoke,
 	.destroy		= user_destroy,
 	.describe		= user_describe,
@@ -56,38 +54,45 @@ struct key_type key_type_logon = {
 EXPORT_SYMBOL_GPL(key_type_logon);
 
 /*
- * instantiate a user defined key
+ * Preparse a user defined key payload
  */
-int user_instantiate(struct key *key, struct key_preparsed_payload *prep)
+int user_preparse(struct key_preparsed_payload *prep)
 {
 	struct user_key_payload *upayload;
 	size_t datalen = prep->datalen;
-	int ret;
-
-	ret = -EINVAL;
-	if (datalen <= 0 || datalen > 32767 || !prep->data)
-		goto error;
 
-	ret = key_payload_reserve(key, datalen);
-	if (ret < 0)
-		goto error;
+	if (datalen == 0 || datalen > 32767 || !prep->data)
+		return -EINVAL;
 
-	ret = -ENOMEM;
 	upayload = kmalloc(sizeof(*upayload) + datalen, GFP_KERNEL);
 	if (!upayload)
-		goto error;
+		return -ENOMEM;
 
 	/* attach the data */
+	prep->quotalen = datalen;
+	prep->payload.data[0] = upayload;
 	upayload->datalen = datalen;
 	memcpy(upayload->data, prep->data, datalen);
-	rcu_assign_keypointer(key, upayload);
-	ret = 0;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(user_preparse);
 
-error:
-	return ret;
+/*
+ * Free a preparse of a user defined key payload
+ */
+void user_free_preparse(struct key_preparsed_payload *prep)
+{
+	kfree_sensitive(prep->payload.data[0]);
 }
+EXPORT_SYMBOL_GPL(user_free_preparse);
 
-EXPORT_SYMBOL_GPL(user_instantiate);
+static void user_free_payload_rcu(struct rcu_head *head)
+{
+	struct user_key_payload *payload;
+
+	payload = container_of(head, struct user_key_payload, rcu);
+	kfree_sensitive(payload);
+}
 
 /*
  * update a user defined key
@@ -95,68 +100,41 @@ EXPORT_SYMBOL_GPL(user_instantiate);
  */
 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);
+	ret = key_payload_reserve(key, prep->datalen);
+	if (ret < 0)
+		return ret;
 
-	if (ret == 0) {
-		/* attach the new data, displacing the old */
-		zap = key->payload.data;
-		rcu_assign_keypointer(key, upayload);
-		key->expiry = 0;
-	}
+	/* attach the new data, displacing the old */
+	key->expiry = prep->expiry;
+	if (key_is_positive(key))
+		zap = dereference_key_locked(key);
+	rcu_assign_keypointer(key, prep->payload.data[0]);
+	prep->payload.data[0] = NULL;
 
 	if (zap)
-		kfree_rcu(zap, rcu);
-
-error:
+		call_rcu(&zap->rcu, user_free_payload_rcu);
 	return ret;
 }
-
 EXPORT_SYMBOL_GPL(user_update);
 
 /*
- * match users on their name
- */
-int user_match(const struct key *key, const void *description)
-{
-	return strcmp(key->description, description) == 0;
-}
-
-EXPORT_SYMBOL_GPL(user_match);
-
-/*
  * dispose of the links from a revoked keyring
  * - called with the key sem write-locked
  */
 void user_revoke(struct key *key)
 {
-	struct user_key_payload *upayload = key->payload.data;
+	struct user_key_payload *upayload = user_key_payload_locked(key);
 
 	/* clear the quota */
 	key_payload_reserve(key, 0);
 
 	if (upayload) {
 		rcu_assign_keypointer(key, NULL);
-		kfree_rcu(upayload, rcu);
+		call_rcu(&upayload->rcu, user_free_payload_rcu);
 	}
 }
 
@@ -167,9 +145,9 @@ EXPORT_SYMBOL(user_revoke);
  */
 void user_destroy(struct key *key)
 {
-	struct user_key_payload *upayload = key->payload.data;
+	struct user_key_payload *upayload = key->payload.data[0];
 
-	kfree(upayload);
+	kfree_sensitive(upayload);
 }
 
 EXPORT_SYMBOL_GPL(user_destroy);
@@ -180,7 +158,7 @@ EXPORT_SYMBOL_GPL(user_destroy);
 void user_describe(const struct key *key, struct seq_file *m)
 {
 	seq_puts(m, key->description);
-	if (key_is_instantiated(key))
+	if (key_is_positive(key))
 		seq_printf(m, ": %u", key->datalen);
 }
 
@@ -190,12 +168,12 @@ EXPORT_SYMBOL_GPL(user_describe);
  * read the key data
  * - the key's semaphore is read-locked
  */
-long user_read(const struct key *key, char __user *buffer, size_t buflen)
+long user_read(const struct key *key, char *buffer, size_t buflen)
 {
-	struct user_key_payload *upayload;
+	const struct user_key_payload *upayload;
 	long ret;
 
-	upayload = rcu_dereference_key(key);
+	upayload = user_key_payload_locked(key);
 	ret = upayload->datalen;
 
 	/* we can return the data as is */
@@ -203,8 +181,7 @@ long user_read(const struct key *key, char __user *buffer, size_t buflen)
 		if (buflen > upayload->datalen)
 			buflen = upayload->datalen;
 
-		if (copy_to_user(buffer, upayload->data, buflen) != 0)
-			ret = -EFAULT;
+		memcpy(buffer, upayload->data, buflen);
 	}
 
 	return ret;