android_kernel_xiaomi_sm8350/crypto/algapi.c
Herbert Xu b8e15992b4 crypto: api - Fix algorithm test race that broke aead initialisation
When we complete a test we'll notify everyone waiting on it, drop
the mutex, and then remove the test larval (after reacquiring the
mutex).  If one of the notified parties tries to register another
algorithm with the same driver name prior to the removal of the
test larval, they will fail with EEXIST as only one algorithm of
a given name can be tested at any time.

This broke the initialisation of aead and givcipher algorithms as
they will register two algorithms with the same driver name, in
sequence.

This patch fixes the problem by marking the larval as dead before
we drop the mutex, and also ignoring all dead or dying algorithms
on the registration path.

Tested-by: Andreas Steffen <andreas.steffen@strongswan.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-01-28 14:09:59 +11:00

790 lines
16 KiB
C

/*
* Cryptographic API for algorithms (i.e., low-level API).
*
* Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
*
* 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/err.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/rtnetlink.h>
#include <linux/string.h>
#include "internal.h"
static void crypto_remove_final(struct list_head *list);
static LIST_HEAD(crypto_template_list);
void crypto_larval_error(const char *name, u32 type, u32 mask)
{
struct crypto_alg *alg;
alg = crypto_alg_lookup(name, type, mask);
if (alg) {
if (crypto_is_larval(alg)) {
struct crypto_larval *larval = (void *)alg;
complete_all(&larval->completion);
}
crypto_mod_put(alg);
}
}
EXPORT_SYMBOL_GPL(crypto_larval_error);
static inline int crypto_set_driver_name(struct crypto_alg *alg)
{
static const char suffix[] = "-generic";
char *driver_name = alg->cra_driver_name;
int len;
if (*driver_name)
return 0;
len = strlcpy(driver_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
if (len + sizeof(suffix) > CRYPTO_MAX_ALG_NAME)
return -ENAMETOOLONG;
memcpy(driver_name + len, suffix, sizeof(suffix));
return 0;
}
static int crypto_check_alg(struct crypto_alg *alg)
{
if (alg->cra_alignmask & (alg->cra_alignmask + 1))
return -EINVAL;
if (alg->cra_blocksize > PAGE_SIZE / 8)
return -EINVAL;
if (alg->cra_priority < 0)
return -EINVAL;
return crypto_set_driver_name(alg);
}
static void crypto_destroy_instance(struct crypto_alg *alg)
{
struct crypto_instance *inst = (void *)alg;
struct crypto_template *tmpl = inst->tmpl;
tmpl->free(inst);
crypto_tmpl_put(tmpl);
}
static void crypto_remove_spawn(struct crypto_spawn *spawn,
struct list_head *list,
struct list_head *secondary_spawns)
{
struct crypto_instance *inst = spawn->inst;
struct crypto_template *tmpl = inst->tmpl;
list_del_init(&spawn->list);
spawn->alg = NULL;
if (crypto_is_dead(&inst->alg))
return;
inst->alg.cra_flags |= CRYPTO_ALG_DEAD;
if (hlist_unhashed(&inst->list))
return;
if (!tmpl || !crypto_tmpl_get(tmpl))
return;
crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, &inst->alg);
list_move(&inst->alg.cra_list, list);
hlist_del(&inst->list);
inst->alg.cra_destroy = crypto_destroy_instance;
list_splice(&inst->alg.cra_users, secondary_spawns);
}
static void crypto_remove_spawns(struct list_head *spawns,
struct list_head *list, u32 new_type)
{
struct crypto_spawn *spawn, *n;
LIST_HEAD(secondary_spawns);
list_for_each_entry_safe(spawn, n, spawns, list) {
if ((spawn->alg->cra_flags ^ new_type) & spawn->mask)
continue;
crypto_remove_spawn(spawn, list, &secondary_spawns);
}
while (!list_empty(&secondary_spawns)) {
list_for_each_entry_safe(spawn, n, &secondary_spawns, list)
crypto_remove_spawn(spawn, list, &secondary_spawns);
}
}
static struct crypto_larval *__crypto_register_alg(struct crypto_alg *alg)
{
struct crypto_alg *q;
struct crypto_larval *larval;
int ret = -EAGAIN;
if (crypto_is_dead(alg))
goto err;
INIT_LIST_HEAD(&alg->cra_users);
/* No cheating! */
alg->cra_flags &= ~CRYPTO_ALG_TESTED;
ret = -EEXIST;
atomic_set(&alg->cra_refcnt, 1);
list_for_each_entry(q, &crypto_alg_list, cra_list) {
if (q == alg)
goto err;
if (crypto_is_moribund(q))
continue;
if (crypto_is_larval(q)) {
if (!strcmp(alg->cra_driver_name, q->cra_driver_name))
goto err;
continue;
}
if (!strcmp(q->cra_driver_name, alg->cra_name) ||
!strcmp(q->cra_name, alg->cra_driver_name))
goto err;
}
larval = crypto_larval_alloc(alg->cra_name,
alg->cra_flags | CRYPTO_ALG_TESTED, 0);
if (IS_ERR(larval))
goto out;
ret = -ENOENT;
larval->adult = crypto_mod_get(alg);
if (!larval->adult)
goto free_larval;
atomic_set(&larval->alg.cra_refcnt, 1);
memcpy(larval->alg.cra_driver_name, alg->cra_driver_name,
CRYPTO_MAX_ALG_NAME);
larval->alg.cra_priority = alg->cra_priority;
list_add(&alg->cra_list, &crypto_alg_list);
list_add(&larval->alg.cra_list, &crypto_alg_list);
out:
return larval;
free_larval:
kfree(larval);
err:
larval = ERR_PTR(ret);
goto out;
}
void crypto_alg_tested(const char *name, int err)
{
struct crypto_larval *test;
struct crypto_alg *alg;
struct crypto_alg *q;
LIST_HEAD(list);
down_write(&crypto_alg_sem);
list_for_each_entry(q, &crypto_alg_list, cra_list) {
if (crypto_is_moribund(q) || !crypto_is_larval(q))
continue;
test = (struct crypto_larval *)q;
if (!strcmp(q->cra_driver_name, name))
goto found;
}
printk(KERN_ERR "alg: Unexpected test result for %s: %d\n", name, err);
goto unlock;
found:
q->cra_flags |= CRYPTO_ALG_DEAD;
alg = test->adult;
if (err || list_empty(&alg->cra_list))
goto complete;
alg->cra_flags |= CRYPTO_ALG_TESTED;
list_for_each_entry(q, &crypto_alg_list, cra_list) {
if (q == alg)
continue;
if (crypto_is_moribund(q))
continue;
if (crypto_is_larval(q)) {
struct crypto_larval *larval = (void *)q;
/*
* Check to see if either our generic name or
* specific name can satisfy the name requested
* by the larval entry q.
*/
if (strcmp(alg->cra_name, q->cra_name) &&
strcmp(alg->cra_driver_name, q->cra_name))
continue;
if (larval->adult)
continue;
if ((q->cra_flags ^ alg->cra_flags) & larval->mask)
continue;
if (!crypto_mod_get(alg))
continue;
larval->adult = alg;
complete_all(&larval->completion);
continue;
}
if (strcmp(alg->cra_name, q->cra_name))
continue;
if (strcmp(alg->cra_driver_name, q->cra_driver_name) &&
q->cra_priority > alg->cra_priority)
continue;
crypto_remove_spawns(&q->cra_users, &list, alg->cra_flags);
}
complete:
complete_all(&test->completion);
unlock:
up_write(&crypto_alg_sem);
crypto_remove_final(&list);
}
EXPORT_SYMBOL_GPL(crypto_alg_tested);
static void crypto_remove_final(struct list_head *list)
{
struct crypto_alg *alg;
struct crypto_alg *n;
list_for_each_entry_safe(alg, n, list, cra_list) {
list_del_init(&alg->cra_list);
crypto_alg_put(alg);
}
}
static void crypto_wait_for_test(struct crypto_larval *larval)
{
int err;
err = crypto_probing_notify(CRYPTO_MSG_ALG_REGISTER, larval->adult);
if (err != NOTIFY_STOP) {
if (WARN_ON(err != NOTIFY_DONE))
goto out;
crypto_alg_tested(larval->alg.cra_driver_name, 0);
}
err = wait_for_completion_interruptible(&larval->completion);
WARN_ON(err);
out:
crypto_larval_kill(&larval->alg);
}
int crypto_register_alg(struct crypto_alg *alg)
{
struct crypto_larval *larval;
int err;
err = crypto_check_alg(alg);
if (err)
return err;
down_write(&crypto_alg_sem);
larval = __crypto_register_alg(alg);
up_write(&crypto_alg_sem);
if (IS_ERR(larval))
return PTR_ERR(larval);
crypto_wait_for_test(larval);
return 0;
}
EXPORT_SYMBOL_GPL(crypto_register_alg);
static int crypto_remove_alg(struct crypto_alg *alg, struct list_head *list)
{
if (unlikely(list_empty(&alg->cra_list)))
return -ENOENT;
alg->cra_flags |= CRYPTO_ALG_DEAD;
crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg);
list_del_init(&alg->cra_list);
crypto_remove_spawns(&alg->cra_users, list, alg->cra_flags);
return 0;
}
int crypto_unregister_alg(struct crypto_alg *alg)
{
int ret;
LIST_HEAD(list);
down_write(&crypto_alg_sem);
ret = crypto_remove_alg(alg, &list);
up_write(&crypto_alg_sem);
if (ret)
return ret;
BUG_ON(atomic_read(&alg->cra_refcnt) != 1);
if (alg->cra_destroy)
alg->cra_destroy(alg);
crypto_remove_final(&list);
return 0;
}
EXPORT_SYMBOL_GPL(crypto_unregister_alg);
int crypto_register_template(struct crypto_template *tmpl)
{
struct crypto_template *q;
int err = -EEXIST;
down_write(&crypto_alg_sem);
list_for_each_entry(q, &crypto_template_list, list) {
if (q == tmpl)
goto out;
}
list_add(&tmpl->list, &crypto_template_list);
crypto_notify(CRYPTO_MSG_TMPL_REGISTER, tmpl);
err = 0;
out:
up_write(&crypto_alg_sem);
return err;
}
EXPORT_SYMBOL_GPL(crypto_register_template);
void crypto_unregister_template(struct crypto_template *tmpl)
{
struct crypto_instance *inst;
struct hlist_node *p, *n;
struct hlist_head *list;
LIST_HEAD(users);
down_write(&crypto_alg_sem);
BUG_ON(list_empty(&tmpl->list));
list_del_init(&tmpl->list);
list = &tmpl->instances;
hlist_for_each_entry(inst, p, list, list) {
int err = crypto_remove_alg(&inst->alg, &users);
BUG_ON(err);
}
crypto_notify(CRYPTO_MSG_TMPL_UNREGISTER, tmpl);
up_write(&crypto_alg_sem);
hlist_for_each_entry_safe(inst, p, n, list, list) {
BUG_ON(atomic_read(&inst->alg.cra_refcnt) != 1);
tmpl->free(inst);
}
crypto_remove_final(&users);
}
EXPORT_SYMBOL_GPL(crypto_unregister_template);
static struct crypto_template *__crypto_lookup_template(const char *name)
{
struct crypto_template *q, *tmpl = NULL;
down_read(&crypto_alg_sem);
list_for_each_entry(q, &crypto_template_list, list) {
if (strcmp(q->name, name))
continue;
if (unlikely(!crypto_tmpl_get(q)))
continue;
tmpl = q;
break;
}
up_read(&crypto_alg_sem);
return tmpl;
}
struct crypto_template *crypto_lookup_template(const char *name)
{
return try_then_request_module(__crypto_lookup_template(name), name);
}
EXPORT_SYMBOL_GPL(crypto_lookup_template);
int crypto_register_instance(struct crypto_template *tmpl,
struct crypto_instance *inst)
{
struct crypto_larval *larval;
int err;
err = crypto_check_alg(&inst->alg);
if (err)
goto err;
inst->alg.cra_module = tmpl->module;
down_write(&crypto_alg_sem);
larval = __crypto_register_alg(&inst->alg);
if (IS_ERR(larval))
goto unlock;
hlist_add_head(&inst->list, &tmpl->instances);
inst->tmpl = tmpl;
unlock:
up_write(&crypto_alg_sem);
err = PTR_ERR(larval);
if (IS_ERR(larval))
goto err;
crypto_wait_for_test(larval);
err = 0;
err:
return err;
}
EXPORT_SYMBOL_GPL(crypto_register_instance);
int crypto_init_spawn(struct crypto_spawn *spawn, struct crypto_alg *alg,
struct crypto_instance *inst, u32 mask)
{
int err = -EAGAIN;
spawn->inst = inst;
spawn->mask = mask;
down_write(&crypto_alg_sem);
if (!crypto_is_moribund(alg)) {
list_add(&spawn->list, &alg->cra_users);
spawn->alg = alg;
err = 0;
}
up_write(&crypto_alg_sem);
return err;
}
EXPORT_SYMBOL_GPL(crypto_init_spawn);
void crypto_drop_spawn(struct crypto_spawn *spawn)
{
down_write(&crypto_alg_sem);
list_del(&spawn->list);
up_write(&crypto_alg_sem);
}
EXPORT_SYMBOL_GPL(crypto_drop_spawn);
struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn, u32 type,
u32 mask)
{
struct crypto_alg *alg;
struct crypto_alg *alg2;
struct crypto_tfm *tfm;
down_read(&crypto_alg_sem);
alg = spawn->alg;
alg2 = alg;
if (alg2)
alg2 = crypto_mod_get(alg2);
up_read(&crypto_alg_sem);
if (!alg2) {
if (alg)
crypto_shoot_alg(alg);
return ERR_PTR(-EAGAIN);
}
tfm = ERR_PTR(-EINVAL);
if (unlikely((alg->cra_flags ^ type) & mask))
goto out_put_alg;
tfm = __crypto_alloc_tfm(alg, type, mask);
if (IS_ERR(tfm))
goto out_put_alg;
return tfm;
out_put_alg:
crypto_mod_put(alg);
return tfm;
}
EXPORT_SYMBOL_GPL(crypto_spawn_tfm);
int crypto_register_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_register(&crypto_chain, nb);
}
EXPORT_SYMBOL_GPL(crypto_register_notifier);
int crypto_unregister_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_unregister(&crypto_chain, nb);
}
EXPORT_SYMBOL_GPL(crypto_unregister_notifier);
struct crypto_attr_type *crypto_get_attr_type(struct rtattr **tb)
{
struct rtattr *rta = tb[0];
struct crypto_attr_type *algt;
if (!rta)
return ERR_PTR(-ENOENT);
if (RTA_PAYLOAD(rta) < sizeof(*algt))
return ERR_PTR(-EINVAL);
if (rta->rta_type != CRYPTOA_TYPE)
return ERR_PTR(-EINVAL);
algt = RTA_DATA(rta);
return algt;
}
EXPORT_SYMBOL_GPL(crypto_get_attr_type);
int crypto_check_attr_type(struct rtattr **tb, u32 type)
{
struct crypto_attr_type *algt;
algt = crypto_get_attr_type(tb);
if (IS_ERR(algt))
return PTR_ERR(algt);
if ((algt->type ^ type) & algt->mask)
return -EINVAL;
return 0;
}
EXPORT_SYMBOL_GPL(crypto_check_attr_type);
const char *crypto_attr_alg_name(struct rtattr *rta)
{
struct crypto_attr_alg *alga;
if (!rta)
return ERR_PTR(-ENOENT);
if (RTA_PAYLOAD(rta) < sizeof(*alga))
return ERR_PTR(-EINVAL);
if (rta->rta_type != CRYPTOA_ALG)
return ERR_PTR(-EINVAL);
alga = RTA_DATA(rta);
alga->name[CRYPTO_MAX_ALG_NAME - 1] = 0;
return alga->name;
}
EXPORT_SYMBOL_GPL(crypto_attr_alg_name);
struct crypto_alg *crypto_attr_alg(struct rtattr *rta, u32 type, u32 mask)
{
const char *name;
int err;
name = crypto_attr_alg_name(rta);
err = PTR_ERR(name);
if (IS_ERR(name))
return ERR_PTR(err);
return crypto_alg_mod_lookup(name, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_attr_alg);
int crypto_attr_u32(struct rtattr *rta, u32 *num)
{
struct crypto_attr_u32 *nu32;
if (!rta)
return -ENOENT;
if (RTA_PAYLOAD(rta) < sizeof(*nu32))
return -EINVAL;
if (rta->rta_type != CRYPTOA_U32)
return -EINVAL;
nu32 = RTA_DATA(rta);
*num = nu32->num;
return 0;
}
EXPORT_SYMBOL_GPL(crypto_attr_u32);
struct crypto_instance *crypto_alloc_instance(const char *name,
struct crypto_alg *alg)
{
struct crypto_instance *inst;
struct crypto_spawn *spawn;
int err;
inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
if (!inst)
return ERR_PTR(-ENOMEM);
err = -ENAMETOOLONG;
if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", name,
alg->cra_name) >= CRYPTO_MAX_ALG_NAME)
goto err_free_inst;
if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
name, alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
goto err_free_inst;
spawn = crypto_instance_ctx(inst);
err = crypto_init_spawn(spawn, alg, inst,
CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);
if (err)
goto err_free_inst;
return inst;
err_free_inst:
kfree(inst);
return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(crypto_alloc_instance);
void crypto_init_queue(struct crypto_queue *queue, unsigned int max_qlen)
{
INIT_LIST_HEAD(&queue->list);
queue->backlog = &queue->list;
queue->qlen = 0;
queue->max_qlen = max_qlen;
}
EXPORT_SYMBOL_GPL(crypto_init_queue);
int crypto_enqueue_request(struct crypto_queue *queue,
struct crypto_async_request *request)
{
int err = -EINPROGRESS;
if (unlikely(queue->qlen >= queue->max_qlen)) {
err = -EBUSY;
if (!(request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG))
goto out;
if (queue->backlog == &queue->list)
queue->backlog = &request->list;
}
queue->qlen++;
list_add_tail(&request->list, &queue->list);
out:
return err;
}
EXPORT_SYMBOL_GPL(crypto_enqueue_request);
struct crypto_async_request *crypto_dequeue_request(struct crypto_queue *queue)
{
struct list_head *request;
if (unlikely(!queue->qlen))
return NULL;
queue->qlen--;
if (queue->backlog != &queue->list)
queue->backlog = queue->backlog->next;
request = queue->list.next;
list_del(request);
return list_entry(request, struct crypto_async_request, list);
}
EXPORT_SYMBOL_GPL(crypto_dequeue_request);
int crypto_tfm_in_queue(struct crypto_queue *queue, struct crypto_tfm *tfm)
{
struct crypto_async_request *req;
list_for_each_entry(req, &queue->list, list) {
if (req->tfm == tfm)
return 1;
}
return 0;
}
EXPORT_SYMBOL_GPL(crypto_tfm_in_queue);
static inline void crypto_inc_byte(u8 *a, unsigned int size)
{
u8 *b = (a + size);
u8 c;
for (; size; size--) {
c = *--b + 1;
*b = c;
if (c)
break;
}
}
void crypto_inc(u8 *a, unsigned int size)
{
__be32 *b = (__be32 *)(a + size);
u32 c;
for (; size >= 4; size -= 4) {
c = be32_to_cpu(*--b) + 1;
*b = cpu_to_be32(c);
if (c)
return;
}
crypto_inc_byte(a, size);
}
EXPORT_SYMBOL_GPL(crypto_inc);
static inline void crypto_xor_byte(u8 *a, const u8 *b, unsigned int size)
{
for (; size; size--)
*a++ ^= *b++;
}
void crypto_xor(u8 *dst, const u8 *src, unsigned int size)
{
u32 *a = (u32 *)dst;
u32 *b = (u32 *)src;
for (; size >= 4; size -= 4)
*a++ ^= *b++;
crypto_xor_byte((u8 *)a, (u8 *)b, size);
}
EXPORT_SYMBOL_GPL(crypto_xor);
static int __init crypto_algapi_init(void)
{
crypto_init_proc();
return 0;
}
static void __exit crypto_algapi_exit(void)
{
crypto_exit_proc();
}
module_init(crypto_algapi_init);
module_exit(crypto_algapi_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Cryptographic algorithms API");