linux-stable/crypto/mcryptd.c
tim 48a992727d crypto: mcryptd - Check mcryptd algorithm compatibility
Algorithms not compatible with mcryptd could be spawned by mcryptd
with a direct crypto_alloc_tfm invocation using a "mcryptd(alg)" name
construct.  This causes mcryptd to crash the kernel if an arbitrary
"alg" is incompatible and not intended to be used with mcryptd.  It is
an issue if AF_ALG tries to spawn mcryptd(alg) to expose it externally.
But such algorithms must be used internally and not be exposed.

We added a check to enforce that only internal algorithms are allowed
with mcryptd at the time mcryptd is spawning an algorithm.

Link: http://marc.info/?l=linux-crypto-vger&m=148063683310477&w=2
Cc: stable@vger.kernel.org
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-12-07 19:55:37 +08:00

704 lines
18 KiB
C

/*
* Software multibuffer async crypto daemon.
*
* Copyright (c) 2014 Tim Chen <tim.c.chen@linux.intel.com>
*
* Adapted from crypto daemon.
*
* 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 <crypto/algapi.h>
#include <crypto/internal/hash.h>
#include <crypto/internal/aead.h>
#include <crypto/mcryptd.h>
#include <crypto/crypto_wq.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/hardirq.h>
#define MCRYPTD_MAX_CPU_QLEN 100
#define MCRYPTD_BATCH 9
static void *mcryptd_alloc_instance(struct crypto_alg *alg, unsigned int head,
unsigned int tail);
struct mcryptd_flush_list {
struct list_head list;
struct mutex lock;
};
static struct mcryptd_flush_list __percpu *mcryptd_flist;
struct hashd_instance_ctx {
struct crypto_ahash_spawn spawn;
struct mcryptd_queue *queue;
};
static void mcryptd_queue_worker(struct work_struct *work);
void mcryptd_arm_flusher(struct mcryptd_alg_cstate *cstate, unsigned long delay)
{
struct mcryptd_flush_list *flist;
if (!cstate->flusher_engaged) {
/* put the flusher on the flush list */
flist = per_cpu_ptr(mcryptd_flist, smp_processor_id());
mutex_lock(&flist->lock);
list_add_tail(&cstate->flush_list, &flist->list);
cstate->flusher_engaged = true;
cstate->next_flush = jiffies + delay;
queue_delayed_work_on(smp_processor_id(), kcrypto_wq,
&cstate->flush, delay);
mutex_unlock(&flist->lock);
}
}
EXPORT_SYMBOL(mcryptd_arm_flusher);
static int mcryptd_init_queue(struct mcryptd_queue *queue,
unsigned int max_cpu_qlen)
{
int cpu;
struct mcryptd_cpu_queue *cpu_queue;
queue->cpu_queue = alloc_percpu(struct mcryptd_cpu_queue);
pr_debug("mqueue:%p mcryptd_cpu_queue %p\n", queue, queue->cpu_queue);
if (!queue->cpu_queue)
return -ENOMEM;
for_each_possible_cpu(cpu) {
cpu_queue = per_cpu_ptr(queue->cpu_queue, cpu);
pr_debug("cpu_queue #%d %p\n", cpu, queue->cpu_queue);
crypto_init_queue(&cpu_queue->queue, max_cpu_qlen);
INIT_WORK(&cpu_queue->work, mcryptd_queue_worker);
}
return 0;
}
static void mcryptd_fini_queue(struct mcryptd_queue *queue)
{
int cpu;
struct mcryptd_cpu_queue *cpu_queue;
for_each_possible_cpu(cpu) {
cpu_queue = per_cpu_ptr(queue->cpu_queue, cpu);
BUG_ON(cpu_queue->queue.qlen);
}
free_percpu(queue->cpu_queue);
}
static int mcryptd_enqueue_request(struct mcryptd_queue *queue,
struct crypto_async_request *request,
struct mcryptd_hash_request_ctx *rctx)
{
int cpu, err;
struct mcryptd_cpu_queue *cpu_queue;
cpu = get_cpu();
cpu_queue = this_cpu_ptr(queue->cpu_queue);
rctx->tag.cpu = cpu;
err = crypto_enqueue_request(&cpu_queue->queue, request);
pr_debug("enqueue request: cpu %d cpu_queue %p request %p\n",
cpu, cpu_queue, request);
queue_work_on(cpu, kcrypto_wq, &cpu_queue->work);
put_cpu();
return err;
}
/*
* Try to opportunisticlly flush the partially completed jobs if
* crypto daemon is the only task running.
*/
static void mcryptd_opportunistic_flush(void)
{
struct mcryptd_flush_list *flist;
struct mcryptd_alg_cstate *cstate;
flist = per_cpu_ptr(mcryptd_flist, smp_processor_id());
while (single_task_running()) {
mutex_lock(&flist->lock);
cstate = list_first_entry_or_null(&flist->list,
struct mcryptd_alg_cstate, flush_list);
if (!cstate || !cstate->flusher_engaged) {
mutex_unlock(&flist->lock);
return;
}
list_del(&cstate->flush_list);
cstate->flusher_engaged = false;
mutex_unlock(&flist->lock);
cstate->alg_state->flusher(cstate);
}
}
/*
* Called in workqueue context, do one real cryption work (via
* req->complete) and reschedule itself if there are more work to
* do.
*/
static void mcryptd_queue_worker(struct work_struct *work)
{
struct mcryptd_cpu_queue *cpu_queue;
struct crypto_async_request *req, *backlog;
int i;
/*
* Need to loop through more than once for multi-buffer to
* be effective.
*/
cpu_queue = container_of(work, struct mcryptd_cpu_queue, work);
i = 0;
while (i < MCRYPTD_BATCH || single_task_running()) {
/*
* preempt_disable/enable is used to prevent
* being preempted by mcryptd_enqueue_request()
*/
local_bh_disable();
preempt_disable();
backlog = crypto_get_backlog(&cpu_queue->queue);
req = crypto_dequeue_request(&cpu_queue->queue);
preempt_enable();
local_bh_enable();
if (!req) {
mcryptd_opportunistic_flush();
return;
}
if (backlog)
backlog->complete(backlog, -EINPROGRESS);
req->complete(req, 0);
if (!cpu_queue->queue.qlen)
return;
++i;
}
if (cpu_queue->queue.qlen)
queue_work(kcrypto_wq, &cpu_queue->work);
}
void mcryptd_flusher(struct work_struct *__work)
{
struct mcryptd_alg_cstate *alg_cpu_state;
struct mcryptd_alg_state *alg_state;
struct mcryptd_flush_list *flist;
int cpu;
cpu = smp_processor_id();
alg_cpu_state = container_of(to_delayed_work(__work),
struct mcryptd_alg_cstate, flush);
alg_state = alg_cpu_state->alg_state;
if (alg_cpu_state->cpu != cpu)
pr_debug("mcryptd error: work on cpu %d, should be cpu %d\n",
cpu, alg_cpu_state->cpu);
if (alg_cpu_state->flusher_engaged) {
flist = per_cpu_ptr(mcryptd_flist, cpu);
mutex_lock(&flist->lock);
list_del(&alg_cpu_state->flush_list);
alg_cpu_state->flusher_engaged = false;
mutex_unlock(&flist->lock);
alg_state->flusher(alg_cpu_state);
}
}
EXPORT_SYMBOL_GPL(mcryptd_flusher);
static inline struct mcryptd_queue *mcryptd_get_queue(struct crypto_tfm *tfm)
{
struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
struct mcryptd_instance_ctx *ictx = crypto_instance_ctx(inst);
return ictx->queue;
}
static void *mcryptd_alloc_instance(struct crypto_alg *alg, unsigned int head,
unsigned int tail)
{
char *p;
struct crypto_instance *inst;
int err;
p = kzalloc(head + sizeof(*inst) + tail, GFP_KERNEL);
if (!p)
return ERR_PTR(-ENOMEM);
inst = (void *)(p + head);
err = -ENAMETOOLONG;
if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
"mcryptd(%s)", alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
goto out_free_inst;
memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
inst->alg.cra_priority = alg->cra_priority + 50;
inst->alg.cra_blocksize = alg->cra_blocksize;
inst->alg.cra_alignmask = alg->cra_alignmask;
out:
return p;
out_free_inst:
kfree(p);
p = ERR_PTR(err);
goto out;
}
static inline bool mcryptd_check_internal(struct rtattr **tb, u32 *type,
u32 *mask)
{
struct crypto_attr_type *algt;
algt = crypto_get_attr_type(tb);
if (IS_ERR(algt))
return false;
*type |= algt->type & CRYPTO_ALG_INTERNAL;
*mask |= algt->mask & CRYPTO_ALG_INTERNAL;
if (*type & *mask & CRYPTO_ALG_INTERNAL)
return true;
else
return false;
}
static int mcryptd_hash_init_tfm(struct crypto_tfm *tfm)
{
struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
struct hashd_instance_ctx *ictx = crypto_instance_ctx(inst);
struct crypto_ahash_spawn *spawn = &ictx->spawn;
struct mcryptd_hash_ctx *ctx = crypto_tfm_ctx(tfm);
struct crypto_ahash *hash;
hash = crypto_spawn_ahash(spawn);
if (IS_ERR(hash))
return PTR_ERR(hash);
ctx->child = hash;
crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
sizeof(struct mcryptd_hash_request_ctx) +
crypto_ahash_reqsize(hash));
return 0;
}
static void mcryptd_hash_exit_tfm(struct crypto_tfm *tfm)
{
struct mcryptd_hash_ctx *ctx = crypto_tfm_ctx(tfm);
crypto_free_ahash(ctx->child);
}
static int mcryptd_hash_setkey(struct crypto_ahash *parent,
const u8 *key, unsigned int keylen)
{
struct mcryptd_hash_ctx *ctx = crypto_ahash_ctx(parent);
struct crypto_ahash *child = ctx->child;
int err;
crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
crypto_ahash_set_flags(child, crypto_ahash_get_flags(parent) &
CRYPTO_TFM_REQ_MASK);
err = crypto_ahash_setkey(child, key, keylen);
crypto_ahash_set_flags(parent, crypto_ahash_get_flags(child) &
CRYPTO_TFM_RES_MASK);
return err;
}
static int mcryptd_hash_enqueue(struct ahash_request *req,
crypto_completion_t complete)
{
int ret;
struct mcryptd_hash_request_ctx *rctx = ahash_request_ctx(req);
struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
struct mcryptd_queue *queue =
mcryptd_get_queue(crypto_ahash_tfm(tfm));
rctx->complete = req->base.complete;
req->base.complete = complete;
ret = mcryptd_enqueue_request(queue, &req->base, rctx);
return ret;
}
static void mcryptd_hash_init(struct crypto_async_request *req_async, int err)
{
struct mcryptd_hash_ctx *ctx = crypto_tfm_ctx(req_async->tfm);
struct crypto_ahash *child = ctx->child;
struct ahash_request *req = ahash_request_cast(req_async);
struct mcryptd_hash_request_ctx *rctx = ahash_request_ctx(req);
struct ahash_request *desc = &rctx->areq;
if (unlikely(err == -EINPROGRESS))
goto out;
ahash_request_set_tfm(desc, child);
ahash_request_set_callback(desc, CRYPTO_TFM_REQ_MAY_SLEEP,
rctx->complete, req_async);
rctx->out = req->result;
err = crypto_ahash_init(desc);
out:
local_bh_disable();
rctx->complete(&req->base, err);
local_bh_enable();
}
static int mcryptd_hash_init_enqueue(struct ahash_request *req)
{
return mcryptd_hash_enqueue(req, mcryptd_hash_init);
}
static void mcryptd_hash_update(struct crypto_async_request *req_async, int err)
{
struct ahash_request *req = ahash_request_cast(req_async);
struct mcryptd_hash_request_ctx *rctx = ahash_request_ctx(req);
if (unlikely(err == -EINPROGRESS))
goto out;
rctx->out = req->result;
err = ahash_mcryptd_update(&rctx->areq);
if (err) {
req->base.complete = rctx->complete;
goto out;
}
return;
out:
local_bh_disable();
rctx->complete(&req->base, err);
local_bh_enable();
}
static int mcryptd_hash_update_enqueue(struct ahash_request *req)
{
return mcryptd_hash_enqueue(req, mcryptd_hash_update);
}
static void mcryptd_hash_final(struct crypto_async_request *req_async, int err)
{
struct ahash_request *req = ahash_request_cast(req_async);
struct mcryptd_hash_request_ctx *rctx = ahash_request_ctx(req);
if (unlikely(err == -EINPROGRESS))
goto out;
rctx->out = req->result;
err = ahash_mcryptd_final(&rctx->areq);
if (err) {
req->base.complete = rctx->complete;
goto out;
}
return;
out:
local_bh_disable();
rctx->complete(&req->base, err);
local_bh_enable();
}
static int mcryptd_hash_final_enqueue(struct ahash_request *req)
{
return mcryptd_hash_enqueue(req, mcryptd_hash_final);
}
static void mcryptd_hash_finup(struct crypto_async_request *req_async, int err)
{
struct ahash_request *req = ahash_request_cast(req_async);
struct mcryptd_hash_request_ctx *rctx = ahash_request_ctx(req);
if (unlikely(err == -EINPROGRESS))
goto out;
rctx->out = req->result;
err = ahash_mcryptd_finup(&rctx->areq);
if (err) {
req->base.complete = rctx->complete;
goto out;
}
return;
out:
local_bh_disable();
rctx->complete(&req->base, err);
local_bh_enable();
}
static int mcryptd_hash_finup_enqueue(struct ahash_request *req)
{
return mcryptd_hash_enqueue(req, mcryptd_hash_finup);
}
static void mcryptd_hash_digest(struct crypto_async_request *req_async, int err)
{
struct mcryptd_hash_ctx *ctx = crypto_tfm_ctx(req_async->tfm);
struct crypto_ahash *child = ctx->child;
struct ahash_request *req = ahash_request_cast(req_async);
struct mcryptd_hash_request_ctx *rctx = ahash_request_ctx(req);
struct ahash_request *desc = &rctx->areq;
if (unlikely(err == -EINPROGRESS))
goto out;
ahash_request_set_tfm(desc, child);
ahash_request_set_callback(desc, CRYPTO_TFM_REQ_MAY_SLEEP,
rctx->complete, req_async);
rctx->out = req->result;
err = ahash_mcryptd_digest(desc);
out:
local_bh_disable();
rctx->complete(&req->base, err);
local_bh_enable();
}
static int mcryptd_hash_digest_enqueue(struct ahash_request *req)
{
return mcryptd_hash_enqueue(req, mcryptd_hash_digest);
}
static int mcryptd_hash_export(struct ahash_request *req, void *out)
{
struct mcryptd_hash_request_ctx *rctx = ahash_request_ctx(req);
return crypto_ahash_export(&rctx->areq, out);
}
static int mcryptd_hash_import(struct ahash_request *req, const void *in)
{
struct mcryptd_hash_request_ctx *rctx = ahash_request_ctx(req);
return crypto_ahash_import(&rctx->areq, in);
}
static int mcryptd_create_hash(struct crypto_template *tmpl, struct rtattr **tb,
struct mcryptd_queue *queue)
{
struct hashd_instance_ctx *ctx;
struct ahash_instance *inst;
struct hash_alg_common *halg;
struct crypto_alg *alg;
u32 type = 0;
u32 mask = 0;
int err;
if (!mcryptd_check_internal(tb, &type, &mask))
return -EINVAL;
halg = ahash_attr_alg(tb[1], type, mask);
if (IS_ERR(halg))
return PTR_ERR(halg);
alg = &halg->base;
pr_debug("crypto: mcryptd hash alg: %s\n", alg->cra_name);
inst = mcryptd_alloc_instance(alg, ahash_instance_headroom(),
sizeof(*ctx));
err = PTR_ERR(inst);
if (IS_ERR(inst))
goto out_put_alg;
ctx = ahash_instance_ctx(inst);
ctx->queue = queue;
err = crypto_init_ahash_spawn(&ctx->spawn, halg,
ahash_crypto_instance(inst));
if (err)
goto out_free_inst;
type = CRYPTO_ALG_ASYNC;
if (alg->cra_flags & CRYPTO_ALG_INTERNAL)
type |= CRYPTO_ALG_INTERNAL;
inst->alg.halg.base.cra_flags = type;
inst->alg.halg.digestsize = halg->digestsize;
inst->alg.halg.statesize = halg->statesize;
inst->alg.halg.base.cra_ctxsize = sizeof(struct mcryptd_hash_ctx);
inst->alg.halg.base.cra_init = mcryptd_hash_init_tfm;
inst->alg.halg.base.cra_exit = mcryptd_hash_exit_tfm;
inst->alg.init = mcryptd_hash_init_enqueue;
inst->alg.update = mcryptd_hash_update_enqueue;
inst->alg.final = mcryptd_hash_final_enqueue;
inst->alg.finup = mcryptd_hash_finup_enqueue;
inst->alg.export = mcryptd_hash_export;
inst->alg.import = mcryptd_hash_import;
inst->alg.setkey = mcryptd_hash_setkey;
inst->alg.digest = mcryptd_hash_digest_enqueue;
err = ahash_register_instance(tmpl, inst);
if (err) {
crypto_drop_ahash(&ctx->spawn);
out_free_inst:
kfree(inst);
}
out_put_alg:
crypto_mod_put(alg);
return err;
}
static struct mcryptd_queue mqueue;
static int mcryptd_create(struct crypto_template *tmpl, struct rtattr **tb)
{
struct crypto_attr_type *algt;
algt = crypto_get_attr_type(tb);
if (IS_ERR(algt))
return PTR_ERR(algt);
switch (algt->type & algt->mask & CRYPTO_ALG_TYPE_MASK) {
case CRYPTO_ALG_TYPE_DIGEST:
return mcryptd_create_hash(tmpl, tb, &mqueue);
break;
}
return -EINVAL;
}
static void mcryptd_free(struct crypto_instance *inst)
{
struct mcryptd_instance_ctx *ctx = crypto_instance_ctx(inst);
struct hashd_instance_ctx *hctx = crypto_instance_ctx(inst);
switch (inst->alg.cra_flags & CRYPTO_ALG_TYPE_MASK) {
case CRYPTO_ALG_TYPE_AHASH:
crypto_drop_ahash(&hctx->spawn);
kfree(ahash_instance(inst));
return;
default:
crypto_drop_spawn(&ctx->spawn);
kfree(inst);
}
}
static struct crypto_template mcryptd_tmpl = {
.name = "mcryptd",
.create = mcryptd_create,
.free = mcryptd_free,
.module = THIS_MODULE,
};
struct mcryptd_ahash *mcryptd_alloc_ahash(const char *alg_name,
u32 type, u32 mask)
{
char mcryptd_alg_name[CRYPTO_MAX_ALG_NAME];
struct crypto_ahash *tfm;
if (snprintf(mcryptd_alg_name, CRYPTO_MAX_ALG_NAME,
"mcryptd(%s)", alg_name) >= CRYPTO_MAX_ALG_NAME)
return ERR_PTR(-EINVAL);
tfm = crypto_alloc_ahash(mcryptd_alg_name, type, mask);
if (IS_ERR(tfm))
return ERR_CAST(tfm);
if (tfm->base.__crt_alg->cra_module != THIS_MODULE) {
crypto_free_ahash(tfm);
return ERR_PTR(-EINVAL);
}
return __mcryptd_ahash_cast(tfm);
}
EXPORT_SYMBOL_GPL(mcryptd_alloc_ahash);
int ahash_mcryptd_digest(struct ahash_request *desc)
{
return crypto_ahash_init(desc) ?: ahash_mcryptd_finup(desc);
}
int ahash_mcryptd_update(struct ahash_request *desc)
{
/* alignment is to be done by multi-buffer crypto algorithm if needed */
return crypto_ahash_update(desc);
}
int ahash_mcryptd_finup(struct ahash_request *desc)
{
/* alignment is to be done by multi-buffer crypto algorithm if needed */
return crypto_ahash_finup(desc);
}
int ahash_mcryptd_final(struct ahash_request *desc)
{
/* alignment is to be done by multi-buffer crypto algorithm if needed */
return crypto_ahash_final(desc);
}
struct crypto_ahash *mcryptd_ahash_child(struct mcryptd_ahash *tfm)
{
struct mcryptd_hash_ctx *ctx = crypto_ahash_ctx(&tfm->base);
return ctx->child;
}
EXPORT_SYMBOL_GPL(mcryptd_ahash_child);
struct ahash_request *mcryptd_ahash_desc(struct ahash_request *req)
{
struct mcryptd_hash_request_ctx *rctx = ahash_request_ctx(req);
return &rctx->areq;
}
EXPORT_SYMBOL_GPL(mcryptd_ahash_desc);
void mcryptd_free_ahash(struct mcryptd_ahash *tfm)
{
crypto_free_ahash(&tfm->base);
}
EXPORT_SYMBOL_GPL(mcryptd_free_ahash);
static int __init mcryptd_init(void)
{
int err, cpu;
struct mcryptd_flush_list *flist;
mcryptd_flist = alloc_percpu(struct mcryptd_flush_list);
for_each_possible_cpu(cpu) {
flist = per_cpu_ptr(mcryptd_flist, cpu);
INIT_LIST_HEAD(&flist->list);
mutex_init(&flist->lock);
}
err = mcryptd_init_queue(&mqueue, MCRYPTD_MAX_CPU_QLEN);
if (err) {
free_percpu(mcryptd_flist);
return err;
}
err = crypto_register_template(&mcryptd_tmpl);
if (err) {
mcryptd_fini_queue(&mqueue);
free_percpu(mcryptd_flist);
}
return err;
}
static void __exit mcryptd_exit(void)
{
mcryptd_fini_queue(&mqueue);
crypto_unregister_template(&mcryptd_tmpl);
free_percpu(mcryptd_flist);
}
subsys_initcall(mcryptd_init);
module_exit(mcryptd_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Software async multibuffer crypto daemon");
MODULE_ALIAS_CRYPTO("mcryptd");