linux/crypto/acompress.c

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Asynchronous Compression operations
*
* Copyright (c) 2016, Intel Corporation
* Authors: Weigang Li <weigang.li@intel.com>
* Giovanni Cabiddu <giovanni.cabiddu@intel.com>
*/
#include <crypto/internal/acompress.h>
#include <linux/cryptouser.h>
#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 <net/netlink.h>
#include "compress.h"
struct crypto_scomp;
static const struct crypto_type crypto_acomp_type;
static inline struct acomp_alg *__crypto_acomp_alg(struct crypto_alg *alg)
{
return container_of(alg, struct acomp_alg, calg.base);
}
static inline struct acomp_alg *crypto_acomp_alg(struct crypto_acomp *tfm)
{
return __crypto_acomp_alg(crypto_acomp_tfm(tfm)->__crt_alg);
}
static int __maybe_unused crypto_acomp_report(
struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_report_acomp racomp;
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 4473710df1f8 ("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 cac5818c25d0 ("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>
2018-11-04 05:56:03 +08:00
memset(&racomp, 0, sizeof(racomp));
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 4473710df1f8 ("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 cac5818c25d0 ("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>
2018-11-04 05:56:03 +08:00
strscpy(racomp.type, "acomp", sizeof(racomp.type));
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 4473710df1f8 ("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 cac5818c25d0 ("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>
2018-11-04 05:56:03 +08:00
return nla_put(skb, CRYPTOCFGA_REPORT_ACOMP, sizeof(racomp), &racomp);
}
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
#if IS_ENABLED(CONFIG_CRYPTO_USER)
.report = crypto_acomp_report,
#endif
.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 crypto_acomp *crypto_alloc_acomp_node(const char *alg_name, u32 type,
u32 mask, int node)
{
return crypto_alloc_tfm_node(alg_name, &crypto_acomp_type, type, mask,
node);
}
EXPORT_SYMBOL_GPL(crypto_alloc_acomp_node);
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);
void comp_prepare_alg(struct comp_alg_common *alg)
{
struct crypto_alg *base = &alg->base;
base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
}
int crypto_register_acomp(struct acomp_alg *alg)
{
struct crypto_alg *base = &alg->calg.base;
comp_prepare_alg(&alg->calg);
base->cra_type = &crypto_acomp_type;
base->cra_flags |= CRYPTO_ALG_TYPE_ACOMPRESS;
return crypto_register_alg(base);
}
EXPORT_SYMBOL_GPL(crypto_register_acomp);
void crypto_unregister_acomp(struct acomp_alg *alg)
{
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");