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linux/crypto/crypto_user_stat.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

431 lines
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// SPDX-License-Identifier: GPL-2.0
/*
* Crypto user configuration API.
*
* Copyright (C) 2017-2018 Corentin Labbe <clabbe@baylibre.com>
*
*/
#include <linux/crypto.h>
#include <linux/cryptouser.h>
#include <linux/sched.h>
#include <net/netlink.h>
#include <crypto/internal/skcipher.h>
#include <crypto/internal/rng.h>
#include <crypto/akcipher.h>
#include <crypto/kpp.h>
#include <crypto/internal/cryptouser.h>
#include "internal.h"
#define null_terminated(x) (strnlen(x, sizeof(x)) < sizeof(x))
static DEFINE_MUTEX(crypto_cfg_mutex);
extern struct sock *crypto_nlsk;
struct crypto_dump_info {
struct sk_buff *in_skb;
struct sk_buff *out_skb;
u32 nlmsg_seq;
u16 nlmsg_flags;
};
static int crypto_report_aead(struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_stat raead;
u64 v64;
u32 v32;
memset(&raead, 0, sizeof(raead));
strscpy(raead.type, "aead", sizeof(raead.type));
v32 = atomic_read(&alg->encrypt_cnt);
raead.stat_encrypt_cnt = v32;
v64 = atomic64_read(&alg->encrypt_tlen);
raead.stat_encrypt_tlen = v64;
v32 = atomic_read(&alg->decrypt_cnt);
raead.stat_decrypt_cnt = v32;
v64 = atomic64_read(&alg->decrypt_tlen);
raead.stat_decrypt_tlen = v64;
v32 = atomic_read(&alg->aead_err_cnt);
raead.stat_aead_err_cnt = v32;
return nla_put(skb, CRYPTOCFGA_STAT_AEAD, sizeof(raead), &raead);
}
static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_stat rcipher;
u64 v64;
u32 v32;
memset(&rcipher, 0, sizeof(rcipher));
strscpy(rcipher.type, "cipher", sizeof(rcipher.type));
v32 = atomic_read(&alg->encrypt_cnt);
rcipher.stat_encrypt_cnt = v32;
v64 = atomic64_read(&alg->encrypt_tlen);
rcipher.stat_encrypt_tlen = v64;
v32 = atomic_read(&alg->decrypt_cnt);
rcipher.stat_decrypt_cnt = v32;
v64 = atomic64_read(&alg->decrypt_tlen);
rcipher.stat_decrypt_tlen = v64;
v32 = atomic_read(&alg->cipher_err_cnt);
rcipher.stat_cipher_err_cnt = v32;
return nla_put(skb, CRYPTOCFGA_STAT_CIPHER, sizeof(rcipher), &rcipher);
}
static int crypto_report_comp(struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_stat rcomp;
u64 v64;
u32 v32;
memset(&rcomp, 0, sizeof(rcomp));
strscpy(rcomp.type, "compression", sizeof(rcomp.type));
v32 = atomic_read(&alg->compress_cnt);
rcomp.stat_compress_cnt = v32;
v64 = atomic64_read(&alg->compress_tlen);
rcomp.stat_compress_tlen = v64;
v32 = atomic_read(&alg->decompress_cnt);
rcomp.stat_decompress_cnt = v32;
v64 = atomic64_read(&alg->decompress_tlen);
rcomp.stat_decompress_tlen = v64;
v32 = atomic_read(&alg->cipher_err_cnt);
rcomp.stat_compress_err_cnt = v32;
return nla_put(skb, CRYPTOCFGA_STAT_COMPRESS, sizeof(rcomp), &rcomp);
}
static int crypto_report_acomp(struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_stat racomp;
u64 v64;
u32 v32;
memset(&racomp, 0, sizeof(racomp));
strscpy(racomp.type, "acomp", sizeof(racomp.type));
v32 = atomic_read(&alg->compress_cnt);
racomp.stat_compress_cnt = v32;
v64 = atomic64_read(&alg->compress_tlen);
racomp.stat_compress_tlen = v64;
v32 = atomic_read(&alg->decompress_cnt);
racomp.stat_decompress_cnt = v32;
v64 = atomic64_read(&alg->decompress_tlen);
racomp.stat_decompress_tlen = v64;
v32 = atomic_read(&alg->cipher_err_cnt);
racomp.stat_compress_err_cnt = v32;
return nla_put(skb, CRYPTOCFGA_STAT_ACOMP, sizeof(racomp), &racomp);
}
static int crypto_report_akcipher(struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_stat rakcipher;
u64 v64;
u32 v32;
memset(&rakcipher, 0, sizeof(rakcipher));
strscpy(rakcipher.type, "akcipher", sizeof(rakcipher.type));
v32 = atomic_read(&alg->encrypt_cnt);
rakcipher.stat_encrypt_cnt = v32;
v64 = atomic64_read(&alg->encrypt_tlen);
rakcipher.stat_encrypt_tlen = v64;
v32 = atomic_read(&alg->decrypt_cnt);
rakcipher.stat_decrypt_cnt = v32;
v64 = atomic64_read(&alg->decrypt_tlen);
rakcipher.stat_decrypt_tlen = v64;
v32 = atomic_read(&alg->sign_cnt);
rakcipher.stat_sign_cnt = v32;
v32 = atomic_read(&alg->verify_cnt);
rakcipher.stat_verify_cnt = v32;
v32 = atomic_read(&alg->akcipher_err_cnt);
rakcipher.stat_akcipher_err_cnt = v32;
return nla_put(skb, CRYPTOCFGA_STAT_AKCIPHER,
sizeof(rakcipher), &rakcipher);
}
static int crypto_report_kpp(struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_stat rkpp;
u32 v;
memset(&rkpp, 0, sizeof(rkpp));
strscpy(rkpp.type, "kpp", sizeof(rkpp.type));
v = atomic_read(&alg->setsecret_cnt);
rkpp.stat_setsecret_cnt = v;
v = atomic_read(&alg->generate_public_key_cnt);
rkpp.stat_generate_public_key_cnt = v;
v = atomic_read(&alg->compute_shared_secret_cnt);
rkpp.stat_compute_shared_secret_cnt = v;
v = atomic_read(&alg->kpp_err_cnt);
rkpp.stat_kpp_err_cnt = v;
return nla_put(skb, CRYPTOCFGA_STAT_KPP, sizeof(rkpp), &rkpp);
}
static int crypto_report_ahash(struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_stat rhash;
u64 v64;
u32 v32;
memset(&rhash, 0, sizeof(rhash));
strscpy(rhash.type, "ahash", sizeof(rhash.type));
v32 = atomic_read(&alg->hash_cnt);
rhash.stat_hash_cnt = v32;
v64 = atomic64_read(&alg->hash_tlen);
rhash.stat_hash_tlen = v64;
v32 = atomic_read(&alg->hash_err_cnt);
rhash.stat_hash_err_cnt = v32;
return nla_put(skb, CRYPTOCFGA_STAT_HASH, sizeof(rhash), &rhash);
}
static int crypto_report_shash(struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_stat rhash;
u64 v64;
u32 v32;
memset(&rhash, 0, sizeof(rhash));
strscpy(rhash.type, "shash", sizeof(rhash.type));
v32 = atomic_read(&alg->hash_cnt);
rhash.stat_hash_cnt = v32;
v64 = atomic64_read(&alg->hash_tlen);
rhash.stat_hash_tlen = v64;
v32 = atomic_read(&alg->hash_err_cnt);
rhash.stat_hash_err_cnt = v32;
return nla_put(skb, CRYPTOCFGA_STAT_HASH, sizeof(rhash), &rhash);
}
static int crypto_report_rng(struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_stat rrng;
u64 v64;
u32 v32;
memset(&rrng, 0, sizeof(rrng));
strscpy(rrng.type, "rng", sizeof(rrng.type));
v32 = atomic_read(&alg->generate_cnt);
rrng.stat_generate_cnt = v32;
v64 = atomic64_read(&alg->generate_tlen);
rrng.stat_generate_tlen = v64;
v32 = atomic_read(&alg->seed_cnt);
rrng.stat_seed_cnt = v32;
v32 = atomic_read(&alg->hash_err_cnt);
rrng.stat_rng_err_cnt = v32;
return nla_put(skb, CRYPTOCFGA_STAT_RNG, sizeof(rrng), &rrng);
}
static int crypto_reportstat_one(struct crypto_alg *alg,
struct crypto_user_alg *ualg,
struct sk_buff *skb)
{
memset(ualg, 0, sizeof(*ualg));
strscpy(ualg->cru_name, alg->cra_name, sizeof(ualg->cru_name));
strscpy(ualg->cru_driver_name, alg->cra_driver_name,
sizeof(ualg->cru_driver_name));
strscpy(ualg->cru_module_name, module_name(alg->cra_module),
sizeof(ualg->cru_module_name));
ualg->cru_type = 0;
ualg->cru_mask = 0;
ualg->cru_flags = alg->cra_flags;
ualg->cru_refcnt = refcount_read(&alg->cra_refcnt);
if (nla_put_u32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority))
goto nla_put_failure;
if (alg->cra_flags & CRYPTO_ALG_LARVAL) {
struct crypto_stat rl;
memset(&rl, 0, sizeof(rl));
strscpy(rl.type, "larval", sizeof(rl.type));
if (nla_put(skb, CRYPTOCFGA_STAT_LARVAL, sizeof(rl), &rl))
goto nla_put_failure;
goto out;
}
switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) {
case CRYPTO_ALG_TYPE_AEAD:
if (crypto_report_aead(skb, alg))
goto nla_put_failure;
break;
case CRYPTO_ALG_TYPE_SKCIPHER:
if (crypto_report_cipher(skb, alg))
goto nla_put_failure;
break;
case CRYPTO_ALG_TYPE_BLKCIPHER:
if (crypto_report_cipher(skb, alg))
goto nla_put_failure;
break;
case CRYPTO_ALG_TYPE_CIPHER:
if (crypto_report_cipher(skb, alg))
goto nla_put_failure;
break;
case CRYPTO_ALG_TYPE_COMPRESS:
if (crypto_report_comp(skb, alg))
goto nla_put_failure;
break;
case CRYPTO_ALG_TYPE_ACOMPRESS:
if (crypto_report_acomp(skb, alg))
goto nla_put_failure;
break;
case CRYPTO_ALG_TYPE_SCOMPRESS:
if (crypto_report_acomp(skb, alg))
goto nla_put_failure;
break;
case CRYPTO_ALG_TYPE_AKCIPHER:
if (crypto_report_akcipher(skb, alg))
goto nla_put_failure;
break;
case CRYPTO_ALG_TYPE_KPP:
if (crypto_report_kpp(skb, alg))
goto nla_put_failure;
break;
case CRYPTO_ALG_TYPE_AHASH:
if (crypto_report_ahash(skb, alg))
goto nla_put_failure;
break;
case CRYPTO_ALG_TYPE_HASH:
if (crypto_report_shash(skb, alg))
goto nla_put_failure;
break;
case CRYPTO_ALG_TYPE_RNG:
if (crypto_report_rng(skb, alg))
goto nla_put_failure;
break;
default:
pr_err("ERROR: Unhandled alg %d in %s\n",
alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL),
__func__);
}
out:
return 0;
nla_put_failure:
return -EMSGSIZE;
}
static int crypto_reportstat_alg(struct crypto_alg *alg,
struct crypto_dump_info *info)
{
struct sk_buff *in_skb = info->in_skb;
struct sk_buff *skb = info->out_skb;
struct nlmsghdr *nlh;
struct crypto_user_alg *ualg;
int err = 0;
nlh = nlmsg_put(skb, NETLINK_CB(in_skb).portid, info->nlmsg_seq,
CRYPTO_MSG_GETSTAT, sizeof(*ualg), info->nlmsg_flags);
if (!nlh) {
err = -EMSGSIZE;
goto out;
}
ualg = nlmsg_data(nlh);
err = crypto_reportstat_one(alg, ualg, skb);
if (err) {
nlmsg_cancel(skb, nlh);
goto out;
}
nlmsg_end(skb, nlh);
out:
return err;
}
int crypto_reportstat(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
struct nlattr **attrs)
{
struct crypto_user_alg *p = nlmsg_data(in_nlh);
struct crypto_alg *alg;
struct sk_buff *skb;
struct crypto_dump_info info;
int err;
if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
return -EINVAL;
alg = crypto_alg_match(p, 0);
if (!alg)
return -ENOENT;
err = -ENOMEM;
skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
if (!skb)
goto drop_alg;
info.in_skb = in_skb;
info.out_skb = skb;
info.nlmsg_seq = in_nlh->nlmsg_seq;
info.nlmsg_flags = 0;
err = crypto_reportstat_alg(alg, &info);
drop_alg:
crypto_mod_put(alg);
if (err)
return err;
return nlmsg_unicast(crypto_nlsk, skb, NETLINK_CB(in_skb).portid);
}
int crypto_dump_reportstat(struct sk_buff *skb, struct netlink_callback *cb)
{
struct crypto_alg *alg;
struct crypto_dump_info info;
int err;
if (cb->args[0])
goto out;
cb->args[0] = 1;
info.in_skb = cb->skb;
info.out_skb = skb;
info.nlmsg_seq = cb->nlh->nlmsg_seq;
info.nlmsg_flags = NLM_F_MULTI;
list_for_each_entry(alg, &crypto_alg_list, cra_list) {
err = crypto_reportstat_alg(alg, &info);
if (err)
goto out_err;
}
out:
return skb->len;
out_err:
return err;
}
int crypto_dump_reportstat_done(struct netlink_callback *cb)
{
return 0;
}
MODULE_LICENSE("GPL");
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