linux_dsm_epyc7002/security/keys/user_defined.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

209 lines
4.6 KiB
C

// 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)
*/
#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 <linux/uaccess.h>
#include "internal.h"
static int logon_vet_description(const char *desc);
/*
* user defined keys take an arbitrary string as the description and an
* arbitrary blob of data as the payload
*/
struct key_type key_type_user = {
.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);
/*
* This key type is essentially the same as key_type_user, but it does
* not define a .read op. This is suitable for storing username and
* password pairs in the keyring that you do not want to be readable
* from userspace.
*/
struct key_type key_type_logon = {
.name = "logon",
.preparse = user_preparse,
.free_preparse = user_free_preparse,
.instantiate = generic_key_instantiate,
.update = user_update,
.revoke = user_revoke,
.destroy = user_destroy,
.describe = user_describe,
.vet_description = logon_vet_description,
};
EXPORT_SYMBOL_GPL(key_type_logon);
/*
* Preparse a user defined key payload
*/
int user_preparse(struct key_preparsed_payload *prep)
{
struct user_key_payload *upayload;
size_t datalen = prep->datalen;
if (datalen <= 0 || datalen > 32767 || !prep->data)
return -EINVAL;
upayload = kmalloc(sizeof(*upayload) + datalen, GFP_KERNEL);
if (!upayload)
return -ENOMEM;
/* attach the data */
prep->quotalen = datalen;
prep->payload.data[0] = upayload;
upayload->datalen = datalen;
memcpy(upayload->data, prep->data, datalen);
return 0;
}
EXPORT_SYMBOL_GPL(user_preparse);
/*
* Free a preparse of a user defined key payload
*/
void user_free_preparse(struct key_preparsed_payload *prep)
{
kzfree(prep->payload.data[0]);
}
EXPORT_SYMBOL_GPL(user_free_preparse);
static void user_free_payload_rcu(struct rcu_head *head)
{
struct user_key_payload *payload;
payload = container_of(head, struct user_key_payload, rcu);
kzfree(payload);
}
/*
* update a user defined key
* - the key's semaphore is write-locked
*/
int user_update(struct key *key, struct key_preparsed_payload *prep)
{
struct user_key_payload *zap = NULL;
int ret;
/* check the quota and attach the new data */
ret = key_payload_reserve(key, prep->datalen);
if (ret < 0)
return ret;
/* 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)
call_rcu(&zap->rcu, user_free_payload_rcu);
return ret;
}
EXPORT_SYMBOL_GPL(user_update);
/*
* 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 = user_key_payload_locked(key);
/* clear the quota */
key_payload_reserve(key, 0);
if (upayload) {
rcu_assign_keypointer(key, NULL);
call_rcu(&upayload->rcu, user_free_payload_rcu);
}
}
EXPORT_SYMBOL(user_revoke);
/*
* dispose of the data dangling from the corpse of a user key
*/
void user_destroy(struct key *key)
{
struct user_key_payload *upayload = key->payload.data[0];
kzfree(upayload);
}
EXPORT_SYMBOL_GPL(user_destroy);
/*
* describe the user key
*/
void user_describe(const struct key *key, struct seq_file *m)
{
seq_puts(m, key->description);
if (key_is_positive(key))
seq_printf(m, ": %u", key->datalen);
}
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)
{
const struct user_key_payload *upayload;
long ret;
upayload = user_key_payload_locked(key);
ret = upayload->datalen;
/* we can return the data as is */
if (buffer && buflen > 0) {
if (buflen > upayload->datalen)
buflen = upayload->datalen;
if (copy_to_user(buffer, upayload->data, buflen) != 0)
ret = -EFAULT;
}
return ret;
}
EXPORT_SYMBOL_GPL(user_read);
/* Vet the description for a "logon" key */
static int logon_vet_description(const char *desc)
{
char *p;
/* require a "qualified" description string */
p = strchr(desc, ':');
if (!p)
return -EINVAL;
/* also reject description with ':' as first char */
if (p == desc)
return -EINVAL;
return 0;
}