kernel-ark/crypto/acompress.c
Eric Biggers 37db69e0b4 crypto: user - clean up report structure copying
There have been a pretty ridiculous number of issues with initializing
the report structures that are copied to userspace by NETLINK_CRYPTO.
Commit 4473710df1 ("crypto: user - Prepare for CRYPTO_MAX_ALG_NAME
expansion") replaced some strncpy()s with strlcpy()s, thereby
introducing information leaks.  Later two other people tried to replace
other strncpy()s with strlcpy() too, which would have introduced even
more information leaks:

    - https://lore.kernel.org/patchwork/patch/954991/
    - https://patchwork.kernel.org/patch/10434351/

Commit cac5818c25 ("crypto: user - Implement a generic crypto
statistics") also uses the buggy strlcpy() approach and therefore leaks
uninitialized memory to userspace.  A fix was proposed, but it was
originally incomplete.

Seeing as how apparently no one can get this right with the current
approach, change all the reporting functions to:

- Start by memsetting the report structure to 0.  This guarantees it's
  always initialized, regardless of what happens later.
- Initialize all strings using strscpy().  This is safe after the
  memset, ensures null termination of long strings, avoids unnecessary
  work, and avoids the -Wstringop-truncation warnings from gcc.
- Use sizeof(var) instead of sizeof(type).  This is more robust against
  copy+paste errors.

For simplicity, also reuse the -EMSGSIZE return value from nla_put().

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-11-09 17:41:39 +08:00

196 lines
4.7 KiB
C

/*
* Asynchronous Compression operations
*
* Copyright (c) 2016, Intel Corporation
* Authors: Weigang Li <weigang.li@intel.com>
* Giovanni Cabiddu <giovanni.cabiddu@intel.com>
*
* 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/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/crypto.h>
#include <crypto/algapi.h>
#include <linux/cryptouser.h>
#include <linux/compiler.h>
#include <net/netlink.h>
#include <crypto/internal/acompress.h>
#include <crypto/internal/scompress.h>
#include "internal.h"
static const struct crypto_type crypto_acomp_type;
#ifdef CONFIG_NET
static int crypto_acomp_report(struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_report_acomp racomp;
memset(&racomp, 0, sizeof(racomp));
strscpy(racomp.type, "acomp", sizeof(racomp.type));
return nla_put(skb, CRYPTOCFGA_REPORT_ACOMP, sizeof(racomp), &racomp);
}
#else
static int crypto_acomp_report(struct sk_buff *skb, struct crypto_alg *alg)
{
return -ENOSYS;
}
#endif
static void crypto_acomp_show(struct seq_file *m, struct crypto_alg *alg)
__maybe_unused;
static void crypto_acomp_show(struct seq_file *m, struct crypto_alg *alg)
{
seq_puts(m, "type : acomp\n");
}
static void crypto_acomp_exit_tfm(struct crypto_tfm *tfm)
{
struct crypto_acomp *acomp = __crypto_acomp_tfm(tfm);
struct acomp_alg *alg = crypto_acomp_alg(acomp);
alg->exit(acomp);
}
static int crypto_acomp_init_tfm(struct crypto_tfm *tfm)
{
struct crypto_acomp *acomp = __crypto_acomp_tfm(tfm);
struct acomp_alg *alg = crypto_acomp_alg(acomp);
if (tfm->__crt_alg->cra_type != &crypto_acomp_type)
return crypto_init_scomp_ops_async(tfm);
acomp->compress = alg->compress;
acomp->decompress = alg->decompress;
acomp->dst_free = alg->dst_free;
acomp->reqsize = alg->reqsize;
if (alg->exit)
acomp->base.exit = crypto_acomp_exit_tfm;
if (alg->init)
return alg->init(acomp);
return 0;
}
static unsigned int crypto_acomp_extsize(struct crypto_alg *alg)
{
int extsize = crypto_alg_extsize(alg);
if (alg->cra_type != &crypto_acomp_type)
extsize += sizeof(struct crypto_scomp *);
return extsize;
}
static const struct crypto_type crypto_acomp_type = {
.extsize = crypto_acomp_extsize,
.init_tfm = crypto_acomp_init_tfm,
#ifdef CONFIG_PROC_FS
.show = crypto_acomp_show,
#endif
.report = crypto_acomp_report,
.maskclear = ~CRYPTO_ALG_TYPE_MASK,
.maskset = CRYPTO_ALG_TYPE_ACOMPRESS_MASK,
.type = CRYPTO_ALG_TYPE_ACOMPRESS,
.tfmsize = offsetof(struct crypto_acomp, base),
};
struct crypto_acomp *crypto_alloc_acomp(const char *alg_name, u32 type,
u32 mask)
{
return crypto_alloc_tfm(alg_name, &crypto_acomp_type, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_alloc_acomp);
struct acomp_req *acomp_request_alloc(struct crypto_acomp *acomp)
{
struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
struct acomp_req *req;
req = __acomp_request_alloc(acomp);
if (req && (tfm->__crt_alg->cra_type != &crypto_acomp_type))
return crypto_acomp_scomp_alloc_ctx(req);
return req;
}
EXPORT_SYMBOL_GPL(acomp_request_alloc);
void acomp_request_free(struct acomp_req *req)
{
struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
if (tfm->__crt_alg->cra_type != &crypto_acomp_type)
crypto_acomp_scomp_free_ctx(req);
if (req->flags & CRYPTO_ACOMP_ALLOC_OUTPUT) {
acomp->dst_free(req->dst);
req->dst = NULL;
}
__acomp_request_free(req);
}
EXPORT_SYMBOL_GPL(acomp_request_free);
int crypto_register_acomp(struct acomp_alg *alg)
{
struct crypto_alg *base = &alg->base;
base->cra_type = &crypto_acomp_type;
base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
base->cra_flags |= CRYPTO_ALG_TYPE_ACOMPRESS;
return crypto_register_alg(base);
}
EXPORT_SYMBOL_GPL(crypto_register_acomp);
int crypto_unregister_acomp(struct acomp_alg *alg)
{
return crypto_unregister_alg(&alg->base);
}
EXPORT_SYMBOL_GPL(crypto_unregister_acomp);
int crypto_register_acomps(struct acomp_alg *algs, int count)
{
int i, ret;
for (i = 0; i < count; i++) {
ret = crypto_register_acomp(&algs[i]);
if (ret)
goto err;
}
return 0;
err:
for (--i; i >= 0; --i)
crypto_unregister_acomp(&algs[i]);
return ret;
}
EXPORT_SYMBOL_GPL(crypto_register_acomps);
void crypto_unregister_acomps(struct acomp_alg *algs, int count)
{
int i;
for (i = count - 1; i >= 0; --i)
crypto_unregister_acomp(&algs[i]);
}
EXPORT_SYMBOL_GPL(crypto_unregister_acomps);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Asynchronous compression type");