linux/crypto/crypto_user.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Crypto user configuration API.
*
* Copyright (C) 2011 secunet Security Networks AG
* Copyright (C) 2011 Steffen Klassert <steffen.klassert@secunet.com>
*/
#include <linux/module.h>
#include <linux/crypto.h>
#include <linux/cryptouser.h>
#include <linux/sched.h>
#include <linux/security.h>
#include <net/netlink.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <crypto/internal/skcipher.h>
#include <crypto/internal/rng.h>
#include <crypto/akcipher.h>
#include <crypto/kpp.h>
#include "internal.h"
#define null_terminated(x) (strnlen(x, sizeof(x)) < sizeof(x))
static DEFINE_MUTEX(crypto_cfg_mutex);
struct crypto_dump_info {
struct sk_buff *in_skb;
struct sk_buff *out_skb;
u32 nlmsg_seq;
u16 nlmsg_flags;
};
crypto: remove CONFIG_CRYPTO_STATS Remove support for the "Crypto usage statistics" feature (CONFIG_CRYPTO_STATS). This feature does not appear to have ever been used, and it is harmful because it significantly reduces performance and is a large maintenance burden. Covering each of these points in detail: 1. Feature is not being used Since these generic crypto statistics are only readable using netlink, it's fairly straightforward to look for programs that use them. I'm unable to find any evidence that any such programs exist. For example, Debian Code Search returns no hits except the kernel header and kernel code itself and translations of the kernel header: https://codesearch.debian.net/search?q=CRYPTOCFGA_STAT&literal=1&perpkg=1 The patch series that added this feature in 2018 (https://lore.kernel.org/linux-crypto/1537351855-16618-1-git-send-email-clabbe@baylibre.com/) said "The goal is to have an ifconfig for crypto device." This doesn't appear to have happened. It's not clear that there is real demand for crypto statistics. Just because the kernel provides other types of statistics such as I/O and networking statistics and some people find those useful does not mean that crypto statistics are useful too. Further evidence that programs are not using CONFIG_CRYPTO_STATS is that it was able to be disabled in RHEL and Fedora as a bug fix (https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/2947). Even further evidence comes from the fact that there are and have been bugs in how the stats work, but they were never reported. For example, before Linux v6.7 hash stats were double-counted in most cases. There has also never been any documentation for this feature, so it might be hard to use even if someone wanted to. 2. CONFIG_CRYPTO_STATS significantly reduces performance Enabling CONFIG_CRYPTO_STATS significantly reduces the performance of the crypto API, even if no program ever retrieves the statistics. This primarily affects systems with a large number of CPUs. For example, https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2039576 reported that Lustre client encryption performance improved from 21.7GB/s to 48.2GB/s by disabling CONFIG_CRYPTO_STATS. It can be argued that this means that CONFIG_CRYPTO_STATS should be optimized with per-cpu counters similar to many of the networking counters. But no one has done this in 5+ years. This is consistent with the fact that the feature appears to be unused, so there seems to be little interest in improving it as opposed to just disabling it. It can be argued that because CONFIG_CRYPTO_STATS is off by default, performance doesn't matter. But Linux distros tend to error on the side of enabling options. The option is enabled in Ubuntu and Arch Linux, and until recently was enabled in RHEL and Fedora (see above). So, even just having the option available is harmful to users. 3. CONFIG_CRYPTO_STATS is a large maintenance burden There are over 1000 lines of code associated with CONFIG_CRYPTO_STATS, spread among 32 files. It significantly complicates much of the implementation of the crypto API. After the initial submission, many fixes and refactorings have consumed effort of multiple people to keep this feature "working". We should be spending this effort elsewhere. Acked-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Corentin Labbe <clabbe@baylibre.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2024-03-13 03:48:21 +00:00
static struct crypto_alg *crypto_alg_match(struct crypto_user_alg *p, int exact)
{
struct crypto_alg *q, *alg = NULL;
down_read(&crypto_alg_sem);
list_for_each_entry(q, &crypto_alg_list, cra_list) {
int match = 0;
crypto: user - prevent operating on larval algorithms Michal Suchanek reported [1] that running the pcrypt_aead01 test from LTP [2] in a loop and holding Ctrl-C causes a NULL dereference of alg->cra_users.next in crypto_remove_spawns(), via crypto_del_alg(). The test repeatedly uses CRYPTO_MSG_NEWALG and CRYPTO_MSG_DELALG. The crash occurs when the instance that CRYPTO_MSG_DELALG is trying to unregister isn't a real registered algorithm, but rather is a "test larval", which is a special "algorithm" added to the algorithms list while the real algorithm is still being tested. Larvals don't have initialized cra_users, so that causes the crash. Normally pcrypt_aead01 doesn't trigger this because CRYPTO_MSG_NEWALG waits for the algorithm to be tested; however, CRYPTO_MSG_NEWALG returns early when interrupted. Everything else in the "crypto user configuration" API has this same bug too, i.e. it inappropriately allows operating on larval algorithms (though it doesn't look like the other cases can cause a crash). Fix this by making crypto_alg_match() exclude larval algorithms. [1] https://lkml.kernel.org/r/20190625071624.27039-1-msuchanek@suse.de [2] https://github.com/linux-test-project/ltp/blob/20190517/testcases/kernel/crypto/pcrypt_aead01.c Reported-by: Michal Suchanek <msuchanek@suse.de> Fixes: a38f7907b926 ("crypto: Add userspace configuration API") Cc: <stable@vger.kernel.org> # v3.2+ Cc: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-07-02 21:17:00 +00:00
if (crypto_is_larval(q))
continue;
if ((q->cra_flags ^ p->cru_type) & p->cru_mask)
continue;
if (strlen(p->cru_driver_name))
match = !strcmp(q->cra_driver_name,
p->cru_driver_name);
else if (!exact)
match = !strcmp(q->cra_name, p->cru_name);
if (!match)
continue;
if (unlikely(!crypto_mod_get(q)))
continue;
alg = q;
break;
}
up_read(&crypto_alg_sem);
return alg;
}
static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_report_cipher rcipher;
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>
2018-11-03 21:56:03 +00:00
memset(&rcipher, 0, sizeof(rcipher));
strscpy(rcipher.type, "cipher", sizeof(rcipher.type));
rcipher.blocksize = alg->cra_blocksize;
rcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
rcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
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>
2018-11-03 21:56:03 +00:00
return nla_put(skb, CRYPTOCFGA_REPORT_CIPHER,
sizeof(rcipher), &rcipher);
}
static int crypto_report_comp(struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_report_comp rcomp;
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>
2018-11-03 21:56:03 +00:00
memset(&rcomp, 0, sizeof(rcomp));
strscpy(rcomp.type, "compression", sizeof(rcomp.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>
2018-11-03 21:56:03 +00:00
return nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS, sizeof(rcomp), &rcomp);
}
static int crypto_report_one(struct crypto_alg *alg,
struct crypto_user_alg *ualg, struct sk_buff *skb)
{
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>
2018-11-03 21:56:03 +00:00
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));
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>
2018-11-03 21:56:03 +00:00
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_report_larval rl;
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>
2018-11-03 21:56:03 +00:00
memset(&rl, 0, sizeof(rl));
strscpy(rl.type, "larval", sizeof(rl.type));
if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL, sizeof(rl), &rl))
goto nla_put_failure;
goto out;
}
if (alg->cra_type && alg->cra_type->report) {
if (alg->cra_type->report(skb, alg))
goto nla_put_failure;
goto out;
}
switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) {
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;
}
out:
return 0;
nla_put_failure:
return -EMSGSIZE;
}
static int crypto_report_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_GETALG, sizeof(*ualg), info->nlmsg_flags);
if (!nlh) {
err = -EMSGSIZE;
goto out;
}
ualg = nlmsg_data(nlh);
err = crypto_report_one(alg, ualg, skb);
if (err) {
nlmsg_cancel(skb, nlh);
goto out;
}
nlmsg_end(skb, nlh);
out:
return err;
}
static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
struct nlattr **attrs)
{
struct net *net = sock_net(in_skb->sk);
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_KERNEL);
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_report_alg(alg, &info);
drop_alg:
crypto_mod_put(alg);
if (err) {
kfree_skb(skb);
return err;
}
return nlmsg_unicast(net->crypto_nlsk, skb, NETLINK_CB(in_skb).portid);
}
static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb)
{
const size_t start_pos = cb->args[0];
size_t pos = 0;
struct crypto_dump_info info;
struct crypto_alg *alg;
int res;
info.in_skb = cb->skb;
info.out_skb = skb;
info.nlmsg_seq = cb->nlh->nlmsg_seq;
info.nlmsg_flags = NLM_F_MULTI;
down_read(&crypto_alg_sem);
list_for_each_entry(alg, &crypto_alg_list, cra_list) {
if (pos >= start_pos) {
res = crypto_report_alg(alg, &info);
if (res == -EMSGSIZE)
break;
if (res)
goto out;
}
pos++;
}
cb->args[0] = pos;
res = skb->len;
out:
up_read(&crypto_alg_sem);
return res;
}
static int crypto_dump_report_done(struct netlink_callback *cb)
{
return 0;
}
static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
struct nlattr **attrs)
{
struct crypto_alg *alg;
struct crypto_user_alg *p = nlmsg_data(nlh);
struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
LIST_HEAD(list);
Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6 into next Pull crypto updates from Herbert Xu: "Here is the crypto update for 3.16: - Added test vectors for SHA/AES-CCM/DES-CBC/3DES-CBC. - Fixed a number of error-path memory leaks in tcrypt. - Fixed error-path memory leak in caam. - Removed unnecessary global mutex from mxs-dcp. - Added ahash walk interface that can actually be asynchronous. - Cleaned up caam error reporting. - Allow crypto_user get operation to be used by non-root users. - Add support for SSS module on Exynos. - Misc fixes" * git://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6: (60 commits) crypto: testmgr - add aead cbc des, des3_ede tests crypto: testmgr - Fix DMA-API warning crypto: cesa - tfm->__crt_alg->cra_type directly crypto: sahara - tfm->__crt_alg->cra_name directly crypto: padlock - tfm->__crt_alg->cra_name directly crypto: n2 - tfm->__crt_alg->cra_name directly crypto: dcp - tfm->__crt_alg->cra_name directly crypto: cesa - tfm->__crt_alg->cra_name directly crypto: ccp - tfm->__crt_alg->cra_name directly crypto: geode - Don't use tfm->__crt_alg->cra_name directly crypto: geode - Weed out printk() from probe() crypto: geode - Consistently use AES_KEYSIZE_128 crypto: geode - Kill AES_IV_LENGTH crypto: geode - Kill AES_MIN_BLOCK_SIZE crypto: mxs-dcp - Remove global mutex crypto: hash - Add real ahash walk interface hwrng: n2-drv - Introduce the use of the managed version of kzalloc crypto: caam - reinitialize keys_fit_inline for decrypt and givencrypt crypto: s5p-sss - fix multiplatform build hwrng: timeriomem - remove unnecessary OOM messages ...
2014-06-08 02:44:40 +00:00
if (!netlink_capable(skb, CAP_NET_ADMIN))
return -EPERM;
if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
return -EINVAL;
if (priority && !strlen(p->cru_driver_name))
return -EINVAL;
alg = crypto_alg_match(p, 1);
if (!alg)
return -ENOENT;
down_write(&crypto_alg_sem);
crypto_remove_spawns(alg, &list, NULL);
if (priority)
alg->cra_priority = nla_get_u32(priority);
up_write(&crypto_alg_sem);
crypto_mod_put(alg);
crypto_remove_final(&list);
return 0;
}
static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
struct nlattr **attrs)
{
struct crypto_alg *alg;
struct crypto_user_alg *p = nlmsg_data(nlh);
int err;
Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6 into next Pull crypto updates from Herbert Xu: "Here is the crypto update for 3.16: - Added test vectors for SHA/AES-CCM/DES-CBC/3DES-CBC. - Fixed a number of error-path memory leaks in tcrypt. - Fixed error-path memory leak in caam. - Removed unnecessary global mutex from mxs-dcp. - Added ahash walk interface that can actually be asynchronous. - Cleaned up caam error reporting. - Allow crypto_user get operation to be used by non-root users. - Add support for SSS module on Exynos. - Misc fixes" * git://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6: (60 commits) crypto: testmgr - add aead cbc des, des3_ede tests crypto: testmgr - Fix DMA-API warning crypto: cesa - tfm->__crt_alg->cra_type directly crypto: sahara - tfm->__crt_alg->cra_name directly crypto: padlock - tfm->__crt_alg->cra_name directly crypto: n2 - tfm->__crt_alg->cra_name directly crypto: dcp - tfm->__crt_alg->cra_name directly crypto: cesa - tfm->__crt_alg->cra_name directly crypto: ccp - tfm->__crt_alg->cra_name directly crypto: geode - Don't use tfm->__crt_alg->cra_name directly crypto: geode - Weed out printk() from probe() crypto: geode - Consistently use AES_KEYSIZE_128 crypto: geode - Kill AES_IV_LENGTH crypto: geode - Kill AES_MIN_BLOCK_SIZE crypto: mxs-dcp - Remove global mutex crypto: hash - Add real ahash walk interface hwrng: n2-drv - Introduce the use of the managed version of kzalloc crypto: caam - reinitialize keys_fit_inline for decrypt and givencrypt crypto: s5p-sss - fix multiplatform build hwrng: timeriomem - remove unnecessary OOM messages ...
2014-06-08 02:44:40 +00:00
if (!netlink_capable(skb, CAP_NET_ADMIN))
return -EPERM;
if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
return -EINVAL;
alg = crypto_alg_match(p, 1);
if (!alg)
return -ENOENT;
/* We can not unregister core algorithms such as aes-generic.
* We would loose the reference in the crypto_alg_list to this algorithm
* if we try to unregister. Unregistering such an algorithm without
* removing the module is not possible, so we restrict to crypto
* instances that are build from templates. */
err = -EINVAL;
if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))
goto drop_alg;
err = -EBUSY;
if (refcount_read(&alg->cra_refcnt) > 2)
goto drop_alg;
crypto_unregister_instance((struct crypto_instance *)alg);
err = 0;
drop_alg:
crypto_mod_put(alg);
return err;
}
static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
struct nlattr **attrs)
{
int exact = 0;
const char *name;
struct crypto_alg *alg;
struct crypto_user_alg *p = nlmsg_data(nlh);
struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6 into next Pull crypto updates from Herbert Xu: "Here is the crypto update for 3.16: - Added test vectors for SHA/AES-CCM/DES-CBC/3DES-CBC. - Fixed a number of error-path memory leaks in tcrypt. - Fixed error-path memory leak in caam. - Removed unnecessary global mutex from mxs-dcp. - Added ahash walk interface that can actually be asynchronous. - Cleaned up caam error reporting. - Allow crypto_user get operation to be used by non-root users. - Add support for SSS module on Exynos. - Misc fixes" * git://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6: (60 commits) crypto: testmgr - add aead cbc des, des3_ede tests crypto: testmgr - Fix DMA-API warning crypto: cesa - tfm->__crt_alg->cra_type directly crypto: sahara - tfm->__crt_alg->cra_name directly crypto: padlock - tfm->__crt_alg->cra_name directly crypto: n2 - tfm->__crt_alg->cra_name directly crypto: dcp - tfm->__crt_alg->cra_name directly crypto: cesa - tfm->__crt_alg->cra_name directly crypto: ccp - tfm->__crt_alg->cra_name directly crypto: geode - Don't use tfm->__crt_alg->cra_name directly crypto: geode - Weed out printk() from probe() crypto: geode - Consistently use AES_KEYSIZE_128 crypto: geode - Kill AES_IV_LENGTH crypto: geode - Kill AES_MIN_BLOCK_SIZE crypto: mxs-dcp - Remove global mutex crypto: hash - Add real ahash walk interface hwrng: n2-drv - Introduce the use of the managed version of kzalloc crypto: caam - reinitialize keys_fit_inline for decrypt and givencrypt crypto: s5p-sss - fix multiplatform build hwrng: timeriomem - remove unnecessary OOM messages ...
2014-06-08 02:44:40 +00:00
if (!netlink_capable(skb, CAP_NET_ADMIN))
return -EPERM;
if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
return -EINVAL;
if (strlen(p->cru_driver_name))
exact = 1;
if (priority && !exact)
return -EINVAL;
alg = crypto_alg_match(p, exact);
if (alg) {
crypto_mod_put(alg);
return -EEXIST;
}
if (strlen(p->cru_driver_name))
name = p->cru_driver_name;
else
name = p->cru_name;
alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask);
if (IS_ERR(alg))
return PTR_ERR(alg);
down_write(&crypto_alg_sem);
if (priority)
alg->cra_priority = nla_get_u32(priority);
up_write(&crypto_alg_sem);
crypto_mod_put(alg);
return 0;
}
static int crypto_del_rng(struct sk_buff *skb, struct nlmsghdr *nlh,
struct nlattr **attrs)
{
if (!netlink_capable(skb, CAP_NET_ADMIN))
return -EPERM;
return crypto_del_default_rng();
}
crypto: remove CONFIG_CRYPTO_STATS Remove support for the "Crypto usage statistics" feature (CONFIG_CRYPTO_STATS). This feature does not appear to have ever been used, and it is harmful because it significantly reduces performance and is a large maintenance burden. Covering each of these points in detail: 1. Feature is not being used Since these generic crypto statistics are only readable using netlink, it's fairly straightforward to look for programs that use them. I'm unable to find any evidence that any such programs exist. For example, Debian Code Search returns no hits except the kernel header and kernel code itself and translations of the kernel header: https://codesearch.debian.net/search?q=CRYPTOCFGA_STAT&literal=1&perpkg=1 The patch series that added this feature in 2018 (https://lore.kernel.org/linux-crypto/1537351855-16618-1-git-send-email-clabbe@baylibre.com/) said "The goal is to have an ifconfig for crypto device." This doesn't appear to have happened. It's not clear that there is real demand for crypto statistics. Just because the kernel provides other types of statistics such as I/O and networking statistics and some people find those useful does not mean that crypto statistics are useful too. Further evidence that programs are not using CONFIG_CRYPTO_STATS is that it was able to be disabled in RHEL and Fedora as a bug fix (https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/2947). Even further evidence comes from the fact that there are and have been bugs in how the stats work, but they were never reported. For example, before Linux v6.7 hash stats were double-counted in most cases. There has also never been any documentation for this feature, so it might be hard to use even if someone wanted to. 2. CONFIG_CRYPTO_STATS significantly reduces performance Enabling CONFIG_CRYPTO_STATS significantly reduces the performance of the crypto API, even if no program ever retrieves the statistics. This primarily affects systems with a large number of CPUs. For example, https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2039576 reported that Lustre client encryption performance improved from 21.7GB/s to 48.2GB/s by disabling CONFIG_CRYPTO_STATS. It can be argued that this means that CONFIG_CRYPTO_STATS should be optimized with per-cpu counters similar to many of the networking counters. But no one has done this in 5+ years. This is consistent with the fact that the feature appears to be unused, so there seems to be little interest in improving it as opposed to just disabling it. It can be argued that because CONFIG_CRYPTO_STATS is off by default, performance doesn't matter. But Linux distros tend to error on the side of enabling options. The option is enabled in Ubuntu and Arch Linux, and until recently was enabled in RHEL and Fedora (see above). So, even just having the option available is harmful to users. 3. CONFIG_CRYPTO_STATS is a large maintenance burden There are over 1000 lines of code associated with CONFIG_CRYPTO_STATS, spread among 32 files. It significantly complicates much of the implementation of the crypto API. After the initial submission, many fixes and refactorings have consumed effort of multiple people to keep this feature "working". We should be spending this effort elsewhere. Acked-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Corentin Labbe <clabbe@baylibre.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2024-03-13 03:48:21 +00:00
static int crypto_reportstat(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
struct nlattr **attrs)
{
/* No longer supported */
return -ENOTSUPP;
}
#define MSGSIZE(type) sizeof(struct type)
static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = {
[CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
[CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
[CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
[CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
[CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = 0,
[CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
};
static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = {
[CRYPTOCFGA_PRIORITY_VAL] = { .type = NLA_U32},
};
#undef MSGSIZE
static const struct crypto_link {
int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **);
int (*dump)(struct sk_buff *, struct netlink_callback *);
int (*done)(struct netlink_callback *);
} crypto_dispatch[CRYPTO_NR_MSGTYPES] = {
[CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg},
[CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg},
[CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg},
[CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = { .doit = crypto_report,
.dump = crypto_dump_report,
.done = crypto_dump_report_done},
[CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = { .doit = crypto_del_rng },
[CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = { .doit = crypto_reportstat},
};
static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(skb->sk);
struct nlattr *attrs[CRYPTOCFGA_MAX+1];
const struct crypto_link *link;
int type, err;
type = nlh->nlmsg_type;
if (type > CRYPTO_MSG_MAX)
return -EINVAL;
type -= CRYPTO_MSG_BASE;
link = &crypto_dispatch[type];
if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) &&
(nlh->nlmsg_flags & NLM_F_DUMP))) {
struct crypto_alg *alg;
unsigned long dump_alloc = 0;
if (link->dump == NULL)
return -EINVAL;
crypto: user - lock crypto_alg_list on alg dump We miss to take the crypto_alg_sem semaphore when traversing the crypto_alg_list for CRYPTO_MSG_GETALG dumps. This allows a race with crypto_unregister_alg() removing algorithms from the list while we're still traversing it, thereby leading to a use-after-free as show below: [ 3482.071639] general protection fault: 0000 [#1] SMP [ 3482.075639] Modules linked in: aes_x86_64 glue_helper lrw ablk_helper cryptd gf128mul ipv6 pcspkr serio_raw virtio_net microcode virtio_pci virtio_ring virtio sr_mod cdrom [last unloaded: aesni_intel] [ 3482.075639] CPU: 1 PID: 11065 Comm: crconf Not tainted 4.3.4-grsec+ #126 [ 3482.075639] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014 [ 3482.075639] task: ffff88001cd41a40 ti: ffff88001cd422c8 task.ti: ffff88001cd422c8 [ 3482.075639] RIP: 0010:[<ffffffff93722bd3>] [<ffffffff93722bd3>] strncpy+0x13/0x30 [ 3482.075639] RSP: 0018:ffff88001f713b60 EFLAGS: 00010202 [ 3482.075639] RAX: ffff88001f6c4430 RBX: ffff88001f6c43a0 RCX: ffff88001f6c4430 [ 3482.075639] RDX: 0000000000000040 RSI: fefefefefefeff16 RDI: ffff88001f6c4430 [ 3482.075639] RBP: ffff88001f713b60 R08: ffff88001f6c4470 R09: ffff88001f6c4480 [ 3482.075639] R10: 0000000000000002 R11: 0000000000000246 R12: ffff88001ce2aa28 [ 3482.075639] R13: ffff880000093700 R14: ffff88001f5e4bf8 R15: 0000000000003b20 [ 3482.075639] FS: 0000033826fa2700(0000) GS:ffff88001e900000(0000) knlGS:0000000000000000 [ 3482.075639] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 3482.075639] CR2: ffffffffff600400 CR3: 00000000139ec000 CR4: 00000000001606f0 [ 3482.075639] Stack: [ 3482.075639] ffff88001f713bd8 ffffffff936ccd00 ffff88001e5c4200 ffff880000093700 [ 3482.075639] ffff88001f713bd0 ffffffff938ef4bf 0000000000000000 0000000000003b20 [ 3482.075639] ffff88001f5e4bf8 ffff88001f5e4848 0000000000000000 0000000000003b20 [ 3482.075639] Call Trace: [ 3482.075639] [<ffffffff936ccd00>] crypto_report_alg+0xc0/0x3e0 [ 3482.075639] [<ffffffff938ef4bf>] ? __alloc_skb+0x16f/0x300 [ 3482.075639] [<ffffffff936cd08a>] crypto_dump_report+0x6a/0x90 [ 3482.075639] [<ffffffff93935707>] netlink_dump+0x147/0x2e0 [ 3482.075639] [<ffffffff93935f99>] __netlink_dump_start+0x159/0x190 [ 3482.075639] [<ffffffff936ccb13>] crypto_user_rcv_msg+0xc3/0x130 [ 3482.075639] [<ffffffff936cd020>] ? crypto_report_alg+0x3e0/0x3e0 [ 3482.075639] [<ffffffff936cc4b0>] ? alg_test_crc32c+0x120/0x120 [ 3482.075639] [<ffffffff93933145>] ? __netlink_lookup+0xd5/0x120 [ 3482.075639] [<ffffffff936cca50>] ? crypto_add_alg+0x1d0/0x1d0 [ 3482.075639] [<ffffffff93938141>] netlink_rcv_skb+0xe1/0x130 [ 3482.075639] [<ffffffff936cc4f8>] crypto_netlink_rcv+0x28/0x40 [ 3482.075639] [<ffffffff939375a8>] netlink_unicast+0x108/0x180 [ 3482.075639] [<ffffffff93937c21>] netlink_sendmsg+0x541/0x770 [ 3482.075639] [<ffffffff938e31e1>] sock_sendmsg+0x21/0x40 [ 3482.075639] [<ffffffff938e4763>] SyS_sendto+0xf3/0x130 [ 3482.075639] [<ffffffff93444203>] ? bad_area_nosemaphore+0x13/0x20 [ 3482.075639] [<ffffffff93444470>] ? __do_page_fault+0x80/0x3a0 [ 3482.075639] [<ffffffff939d80cb>] entry_SYSCALL_64_fastpath+0x12/0x6e [ 3482.075639] Code: 88 4a ff 75 ed 5d 48 0f ba 2c 24 3f c3 66 66 2e 0f 1f 84 00 00 00 00 00 55 48 85 d2 48 89 f8 48 89 f9 4c 8d 04 17 48 89 e5 74 15 <0f> b6 16 80 fa 01 88 11 48 83 de ff 48 83 c1 01 4c 39 c1 75 eb [ 3482.075639] RIP [<ffffffff93722bd3>] strncpy+0x13/0x30 To trigger the race run the following loops simultaneously for a while: $ while : ; do modprobe aesni-intel; rmmod aesni-intel; done $ while : ; do crconf show all > /dev/null; done Fix the race by taking the crypto_alg_sem read lock, thereby preventing crypto_unregister_alg() from modifying the algorithm list during the dump. This bug has been detected by the PaX memory sanitize feature. Cc: stable@vger.kernel.org Signed-off-by: Mathias Krause <minipli@googlemail.com> Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: PaX Team <pageexec@freemail.hu> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-02-01 13:27:30 +00:00
down_read(&crypto_alg_sem);
list_for_each_entry(alg, &crypto_alg_list, cra_list)
dump_alloc += CRYPTO_REPORT_MAXSIZE;
up_read(&crypto_alg_sem);
{
struct netlink_dump_control c = {
.dump = link->dump,
.done = link->done,
.min_dump_alloc = min(dump_alloc, 65535UL),
};
err = netlink_dump_start(net->crypto_nlsk, skb, nlh, &c);
}
crypto: user - lock crypto_alg_list on alg dump We miss to take the crypto_alg_sem semaphore when traversing the crypto_alg_list for CRYPTO_MSG_GETALG dumps. This allows a race with crypto_unregister_alg() removing algorithms from the list while we're still traversing it, thereby leading to a use-after-free as show below: [ 3482.071639] general protection fault: 0000 [#1] SMP [ 3482.075639] Modules linked in: aes_x86_64 glue_helper lrw ablk_helper cryptd gf128mul ipv6 pcspkr serio_raw virtio_net microcode virtio_pci virtio_ring virtio sr_mod cdrom [last unloaded: aesni_intel] [ 3482.075639] CPU: 1 PID: 11065 Comm: crconf Not tainted 4.3.4-grsec+ #126 [ 3482.075639] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014 [ 3482.075639] task: ffff88001cd41a40 ti: ffff88001cd422c8 task.ti: ffff88001cd422c8 [ 3482.075639] RIP: 0010:[<ffffffff93722bd3>] [<ffffffff93722bd3>] strncpy+0x13/0x30 [ 3482.075639] RSP: 0018:ffff88001f713b60 EFLAGS: 00010202 [ 3482.075639] RAX: ffff88001f6c4430 RBX: ffff88001f6c43a0 RCX: ffff88001f6c4430 [ 3482.075639] RDX: 0000000000000040 RSI: fefefefefefeff16 RDI: ffff88001f6c4430 [ 3482.075639] RBP: ffff88001f713b60 R08: ffff88001f6c4470 R09: ffff88001f6c4480 [ 3482.075639] R10: 0000000000000002 R11: 0000000000000246 R12: ffff88001ce2aa28 [ 3482.075639] R13: ffff880000093700 R14: ffff88001f5e4bf8 R15: 0000000000003b20 [ 3482.075639] FS: 0000033826fa2700(0000) GS:ffff88001e900000(0000) knlGS:0000000000000000 [ 3482.075639] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 3482.075639] CR2: ffffffffff600400 CR3: 00000000139ec000 CR4: 00000000001606f0 [ 3482.075639] Stack: [ 3482.075639] ffff88001f713bd8 ffffffff936ccd00 ffff88001e5c4200 ffff880000093700 [ 3482.075639] ffff88001f713bd0 ffffffff938ef4bf 0000000000000000 0000000000003b20 [ 3482.075639] ffff88001f5e4bf8 ffff88001f5e4848 0000000000000000 0000000000003b20 [ 3482.075639] Call Trace: [ 3482.075639] [<ffffffff936ccd00>] crypto_report_alg+0xc0/0x3e0 [ 3482.075639] [<ffffffff938ef4bf>] ? __alloc_skb+0x16f/0x300 [ 3482.075639] [<ffffffff936cd08a>] crypto_dump_report+0x6a/0x90 [ 3482.075639] [<ffffffff93935707>] netlink_dump+0x147/0x2e0 [ 3482.075639] [<ffffffff93935f99>] __netlink_dump_start+0x159/0x190 [ 3482.075639] [<ffffffff936ccb13>] crypto_user_rcv_msg+0xc3/0x130 [ 3482.075639] [<ffffffff936cd020>] ? crypto_report_alg+0x3e0/0x3e0 [ 3482.075639] [<ffffffff936cc4b0>] ? alg_test_crc32c+0x120/0x120 [ 3482.075639] [<ffffffff93933145>] ? __netlink_lookup+0xd5/0x120 [ 3482.075639] [<ffffffff936cca50>] ? crypto_add_alg+0x1d0/0x1d0 [ 3482.075639] [<ffffffff93938141>] netlink_rcv_skb+0xe1/0x130 [ 3482.075639] [<ffffffff936cc4f8>] crypto_netlink_rcv+0x28/0x40 [ 3482.075639] [<ffffffff939375a8>] netlink_unicast+0x108/0x180 [ 3482.075639] [<ffffffff93937c21>] netlink_sendmsg+0x541/0x770 [ 3482.075639] [<ffffffff938e31e1>] sock_sendmsg+0x21/0x40 [ 3482.075639] [<ffffffff938e4763>] SyS_sendto+0xf3/0x130 [ 3482.075639] [<ffffffff93444203>] ? bad_area_nosemaphore+0x13/0x20 [ 3482.075639] [<ffffffff93444470>] ? __do_page_fault+0x80/0x3a0 [ 3482.075639] [<ffffffff939d80cb>] entry_SYSCALL_64_fastpath+0x12/0x6e [ 3482.075639] Code: 88 4a ff 75 ed 5d 48 0f ba 2c 24 3f c3 66 66 2e 0f 1f 84 00 00 00 00 00 55 48 85 d2 48 89 f8 48 89 f9 4c 8d 04 17 48 89 e5 74 15 <0f> b6 16 80 fa 01 88 11 48 83 de ff 48 83 c1 01 4c 39 c1 75 eb [ 3482.075639] RIP [<ffffffff93722bd3>] strncpy+0x13/0x30 To trigger the race run the following loops simultaneously for a while: $ while : ; do modprobe aesni-intel; rmmod aesni-intel; done $ while : ; do crconf show all > /dev/null; done Fix the race by taking the crypto_alg_sem read lock, thereby preventing crypto_unregister_alg() from modifying the algorithm list during the dump. This bug has been detected by the PaX memory sanitize feature. Cc: stable@vger.kernel.org Signed-off-by: Mathias Krause <minipli@googlemail.com> Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: PaX Team <pageexec@freemail.hu> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-02-01 13:27:30 +00:00
return err;
}
netlink: make validation more configurable for future strictness We currently have two levels of strict validation: 1) liberal (default) - undefined (type >= max) & NLA_UNSPEC attributes accepted - attribute length >= expected accepted - garbage at end of message accepted 2) strict (opt-in) - NLA_UNSPEC attributes accepted - attribute length >= expected accepted Split out parsing strictness into four different options: * TRAILING - check that there's no trailing data after parsing attributes (in message or nested) * MAXTYPE - reject attrs > max known type * UNSPEC - reject attributes with NLA_UNSPEC policy entries * STRICT_ATTRS - strictly validate attribute size The default for future things should be *everything*. The current *_strict() is a combination of TRAILING and MAXTYPE, and is renamed to _deprecated_strict(). The current regular parsing has none of this, and is renamed to *_parse_deprecated(). Additionally it allows us to selectively set one of the new flags even on old policies. Notably, the UNSPEC flag could be useful in this case, since it can be arranged (by filling in the policy) to not be an incompatible userspace ABI change, but would then going forward prevent forgetting attribute entries. Similar can apply to the POLICY flag. We end up with the following renames: * nla_parse -> nla_parse_deprecated * nla_parse_strict -> nla_parse_deprecated_strict * nlmsg_parse -> nlmsg_parse_deprecated * nlmsg_parse_strict -> nlmsg_parse_deprecated_strict * nla_parse_nested -> nla_parse_nested_deprecated * nla_validate_nested -> nla_validate_nested_deprecated Using spatch, of course: @@ expression TB, MAX, HEAD, LEN, POL, EXT; @@ -nla_parse(TB, MAX, HEAD, LEN, POL, EXT) +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression TB, MAX, NLA, POL, EXT; @@ -nla_parse_nested(TB, MAX, NLA, POL, EXT) +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT) @@ expression START, MAX, POL, EXT; @@ -nla_validate_nested(START, MAX, POL, EXT) +nla_validate_nested_deprecated(START, MAX, POL, EXT) @@ expression NLH, HDRLEN, MAX, POL, EXT; @@ -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT) +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT) For this patch, don't actually add the strict, non-renamed versions yet so that it breaks compile if I get it wrong. Also, while at it, make nla_validate and nla_parse go down to a common __nla_validate_parse() function to avoid code duplication. Ultimately, this allows us to have very strict validation for every new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the next patch, while existing things will continue to work as is. In effect then, this adds fully strict validation for any new command. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-26 12:07:28 +00:00
err = nlmsg_parse_deprecated(nlh, crypto_msg_min[type], attrs,
CRYPTOCFGA_MAX, crypto_policy, extack);
if (err < 0)
return err;
if (link->doit == NULL)
return -EINVAL;
return link->doit(skb, nlh, attrs);
}
static void crypto_netlink_rcv(struct sk_buff *skb)
{
mutex_lock(&crypto_cfg_mutex);
netlink_rcv_skb(skb, &crypto_user_rcv_msg);
mutex_unlock(&crypto_cfg_mutex);
}
static int __net_init crypto_netlink_init(struct net *net)
{
struct netlink_kernel_cfg cfg = {
.input = crypto_netlink_rcv,
};
net->crypto_nlsk = netlink_kernel_create(net, NETLINK_CRYPTO, &cfg);
return net->crypto_nlsk == NULL ? -ENOMEM : 0;
}
static void __net_exit crypto_netlink_exit(struct net *net)
{
netlink_kernel_release(net->crypto_nlsk);
net->crypto_nlsk = NULL;
}
static struct pernet_operations crypto_netlink_net_ops = {
.init = crypto_netlink_init,
.exit = crypto_netlink_exit,
};
static int __init crypto_user_init(void)
{
return register_pernet_subsys(&crypto_netlink_net_ops);
}
static void __exit crypto_user_exit(void)
{
unregister_pernet_subsys(&crypto_netlink_net_ops);
}
module_init(crypto_user_init);
module_exit(crypto_user_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
MODULE_DESCRIPTION("Crypto userspace configuration API");
MODULE_ALIAS("net-pf-16-proto-21");