linux/drivers/crypto/nx/nx-sha256.c
Herbert Xu 030f4e9687 crypto: nx - Fix reentrancy bugs
This patch fixes a host of reentrancy bugs in the nx driver.  The
following algorithms are affected:

* CCM
* GCM
* CTR
* XCBC
* SHA256
* SHA512

The crypto API allows a single transform to be used by multiple
threads simultaneously.  For example, IPsec will use a single tfm
to process packets for a given SA.  As packets may arrive on
multiple CPUs that tfm must be reentrant.

The nx driver does try to deal with this by using a spin lock.
Unfortunately only the basic AES/CBC/ECB algorithms do this in
the correct way.

The symptom of these bugs may range from the generation of incorrect
output to memory corruption.

Cc: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-07-08 15:14:13 +08:00

294 lines
7.9 KiB
C

/**
* SHA-256 routines supporting the Power 7+ Nest Accelerators driver
*
* Copyright (C) 2011-2012 International Business Machines Inc.
*
* 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 only.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Author: Kent Yoder <yoder1@us.ibm.com>
*/
#include <crypto/internal/hash.h>
#include <crypto/sha.h>
#include <linux/module.h>
#include <asm/vio.h>
#include <asm/byteorder.h>
#include "nx_csbcpb.h"
#include "nx.h"
static int nx_crypto_ctx_sha256_init(struct crypto_tfm *tfm)
{
struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(tfm);
int err;
err = nx_crypto_ctx_sha_init(tfm);
if (err)
return err;
nx_ctx_init(nx_ctx, HCOP_FC_SHA);
nx_ctx->ap = &nx_ctx->props[NX_PROPS_SHA256];
NX_CPB_SET_DIGEST_SIZE(nx_ctx->csbcpb, NX_DS_SHA256);
return 0;
}
static int nx_sha256_init(struct shash_desc *desc) {
struct sha256_state *sctx = shash_desc_ctx(desc);
memset(sctx, 0, sizeof *sctx);
sctx->state[0] = __cpu_to_be32(SHA256_H0);
sctx->state[1] = __cpu_to_be32(SHA256_H1);
sctx->state[2] = __cpu_to_be32(SHA256_H2);
sctx->state[3] = __cpu_to_be32(SHA256_H3);
sctx->state[4] = __cpu_to_be32(SHA256_H4);
sctx->state[5] = __cpu_to_be32(SHA256_H5);
sctx->state[6] = __cpu_to_be32(SHA256_H6);
sctx->state[7] = __cpu_to_be32(SHA256_H7);
sctx->count = 0;
return 0;
}
static int nx_sha256_update(struct shash_desc *desc, const u8 *data,
unsigned int len)
{
struct sha256_state *sctx = shash_desc_ctx(desc);
struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
struct nx_sg *in_sg;
struct nx_sg *out_sg;
u64 to_process = 0, leftover, total;
unsigned long irq_flags;
int rc = 0;
int data_len;
u32 max_sg_len;
u64 buf_len = (sctx->count % SHA256_BLOCK_SIZE);
spin_lock_irqsave(&nx_ctx->lock, irq_flags);
/* 2 cases for total data len:
* 1: < SHA256_BLOCK_SIZE: copy into state, return 0
* 2: >= SHA256_BLOCK_SIZE: process X blocks, copy in leftover
*/
total = (sctx->count % SHA256_BLOCK_SIZE) + len;
if (total < SHA256_BLOCK_SIZE) {
memcpy(sctx->buf + buf_len, data, len);
sctx->count += len;
goto out;
}
memcpy(csbcpb->cpb.sha256.message_digest, sctx->state, SHA256_DIGEST_SIZE);
NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
in_sg = nx_ctx->in_sg;
max_sg_len = min_t(u64, nx_ctx->ap->sglen,
nx_driver.of.max_sg_len/sizeof(struct nx_sg));
max_sg_len = min_t(u64, max_sg_len,
nx_ctx->ap->databytelen/NX_PAGE_SIZE);
data_len = SHA256_DIGEST_SIZE;
out_sg = nx_build_sg_list(nx_ctx->out_sg, (u8 *)sctx->state,
&data_len, max_sg_len);
nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);
if (data_len != SHA256_DIGEST_SIZE) {
rc = -EINVAL;
goto out;
}
do {
/*
* to_process: the SHA256_BLOCK_SIZE data chunk to process in
* this update. This value is also restricted by the sg list
* limits.
*/
to_process = total - to_process;
to_process = to_process & ~(SHA256_BLOCK_SIZE - 1);
if (buf_len) {
data_len = buf_len;
in_sg = nx_build_sg_list(nx_ctx->in_sg,
(u8 *) sctx->buf,
&data_len,
max_sg_len);
if (data_len != buf_len) {
rc = -EINVAL;
goto out;
}
}
data_len = to_process - buf_len;
in_sg = nx_build_sg_list(in_sg, (u8 *) data,
&data_len, max_sg_len);
nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg);
to_process = (data_len + buf_len);
leftover = total - to_process;
/*
* we've hit the nx chip previously and we're updating
* again, so copy over the partial digest.
*/
memcpy(csbcpb->cpb.sha256.input_partial_digest,
csbcpb->cpb.sha256.message_digest,
SHA256_DIGEST_SIZE);
if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) {
rc = -EINVAL;
goto out;
}
rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP);
if (rc)
goto out;
atomic_inc(&(nx_ctx->stats->sha256_ops));
total -= to_process;
data += to_process - buf_len;
buf_len = 0;
} while (leftover >= SHA256_BLOCK_SIZE);
/* copy the leftover back into the state struct */
if (leftover)
memcpy(sctx->buf, data, leftover);
sctx->count += len;
memcpy(sctx->state, csbcpb->cpb.sha256.message_digest, SHA256_DIGEST_SIZE);
out:
spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
return rc;
}
static int nx_sha256_final(struct shash_desc *desc, u8 *out)
{
struct sha256_state *sctx = shash_desc_ctx(desc);
struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
struct nx_sg *in_sg, *out_sg;
unsigned long irq_flags;
u32 max_sg_len;
int rc = 0;
int len;
spin_lock_irqsave(&nx_ctx->lock, irq_flags);
max_sg_len = min_t(u64, nx_ctx->ap->sglen,
nx_driver.of.max_sg_len/sizeof(struct nx_sg));
max_sg_len = min_t(u64, max_sg_len,
nx_ctx->ap->databytelen/NX_PAGE_SIZE);
/* final is represented by continuing the operation and indicating that
* this is not an intermediate operation */
if (sctx->count >= SHA256_BLOCK_SIZE) {
/* we've hit the nx chip previously, now we're finalizing,
* so copy over the partial digest */
memcpy(csbcpb->cpb.sha256.input_partial_digest, sctx->state, SHA256_DIGEST_SIZE);
NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
} else {
NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
NX_CPB_FDM(csbcpb) &= ~NX_FDM_CONTINUATION;
}
csbcpb->cpb.sha256.message_bit_length = (u64) (sctx->count * 8);
len = sctx->count & (SHA256_BLOCK_SIZE - 1);
in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *) sctx->buf,
&len, max_sg_len);
if (len != (sctx->count & (SHA256_BLOCK_SIZE - 1))) {
rc = -EINVAL;
goto out;
}
len = SHA256_DIGEST_SIZE;
out_sg = nx_build_sg_list(nx_ctx->out_sg, out, &len, max_sg_len);
if (len != SHA256_DIGEST_SIZE) {
rc = -EINVAL;
goto out;
}
nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg);
nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);
if (!nx_ctx->op.outlen) {
rc = -EINVAL;
goto out;
}
rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP);
if (rc)
goto out;
atomic_inc(&(nx_ctx->stats->sha256_ops));
atomic64_add(sctx->count, &(nx_ctx->stats->sha256_bytes));
memcpy(out, csbcpb->cpb.sha256.message_digest, SHA256_DIGEST_SIZE);
out:
spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
return rc;
}
static int nx_sha256_export(struct shash_desc *desc, void *out)
{
struct sha256_state *sctx = shash_desc_ctx(desc);
memcpy(out, sctx, sizeof(*sctx));
return 0;
}
static int nx_sha256_import(struct shash_desc *desc, const void *in)
{
struct sha256_state *sctx = shash_desc_ctx(desc);
memcpy(sctx, in, sizeof(*sctx));
return 0;
}
struct shash_alg nx_shash_sha256_alg = {
.digestsize = SHA256_DIGEST_SIZE,
.init = nx_sha256_init,
.update = nx_sha256_update,
.final = nx_sha256_final,
.export = nx_sha256_export,
.import = nx_sha256_import,
.descsize = sizeof(struct sha256_state),
.statesize = sizeof(struct sha256_state),
.base = {
.cra_name = "sha256",
.cra_driver_name = "sha256-nx",
.cra_priority = 300,
.cra_flags = CRYPTO_ALG_TYPE_SHASH,
.cra_blocksize = SHA256_BLOCK_SIZE,
.cra_module = THIS_MODULE,
.cra_ctxsize = sizeof(struct nx_crypto_ctx),
.cra_init = nx_crypto_ctx_sha256_init,
.cra_exit = nx_crypto_ctx_exit,
}
};