linux/security/keys/encrypted-keys/masterkey_trusted.c
Mimi Zohar 6ac6172a93 encrypted-keys: fix rcu and sparse messages
Enabling CONFIG_PROVE_RCU and CONFIG_SPARSE_RCU_POINTER resulted in
"suspicious rcu_dereference_check() usage!" and "incompatible types
in comparison expression (different address spaces)" messages.

Access the masterkey directly when holding the rwsem.

Changelog v1:
- Use either rcu_read_lock()/rcu_derefence_key()/rcu_read_unlock()
or remove the unnecessary rcu_derefence() - David Howells

Reported-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2012-01-18 10:41:30 +11:00

47 lines
1.3 KiB
C

/*
* Copyright (C) 2010 IBM Corporation
* Copyright (C) 2010 Politecnico di Torino, Italy
* TORSEC group -- http://security.polito.it
*
* Authors:
* Mimi Zohar <zohar@us.ibm.com>
* Roberto Sassu <roberto.sassu@polito.it>
*
* 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, version 2 of the License.
*
* See Documentation/security/keys-trusted-encrypted.txt
*/
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/err.h>
#include <keys/trusted-type.h>
#include <keys/encrypted-type.h>
#include "encrypted.h"
/*
* request_trusted_key - request the trusted key
*
* Trusted keys are sealed to PCRs and other metadata. Although userspace
* manages both trusted/encrypted key-types, like the encrypted key type
* data, trusted key type data is not visible decrypted from userspace.
*/
struct key *request_trusted_key(const char *trusted_desc,
u8 **master_key, size_t *master_keylen)
{
struct trusted_key_payload *tpayload;
struct key *tkey;
tkey = request_key(&key_type_trusted, trusted_desc, NULL);
if (IS_ERR(tkey))
goto error;
down_read(&tkey->sem);
tpayload = tkey->payload.data;
*master_key = tpayload->key;
*master_keylen = tpayload->key_len;
error:
return tkey;
}