Revision - 89c3842 - of, numa: Validate some distance map rules

Revision 89c38422e072bb453e3045b8f1b962a344c3edea authored by John Garry on 08 November 2018, 10:17:03 UTC, committed by Rob Herring on 08 November 2018, 18:44:34 UTC

of, numa: Validate some distance map rules

Currently the NUMA distance map parsing does not validate the distance
table for the distance-matrix rules 1-2 in [1].

However the arch NUMA code may enforce some of these rules, but not all.
Such is the case for the arm64 port, which does not enforce the rule that
the distance between separates nodes cannot equal LOCAL_DISTANCE.

The patch adds the following rules validation:
- distance of node to self equals LOCAL_DISTANCE
- distance of separate nodes > LOCAL_DISTANCE

This change avoids a yet-unresolved crash reported in [2].

A note on dealing with symmetrical distances between nodes:

Validating symmetrical distances between nodes is difficult. If it were
mandated in the bindings that every distance must be recorded in the
table, then it would be easy. However, it isn't.

In addition to this, it is also possible to record [b, a] distance only
(and not [a, b]). So, when processing the table for [b, a], we cannot
assert that current distance of [a, b] != [b, a] as invalid, as [a, b]
distance may not be present in the table and current distance would be
default at REMOTE_DISTANCE.

As such, we maintain the policy that we overwrite distance [a, b] = [b, a]
for b > a. This policy is different to kernel ACPI SLIT validation, which
allows non-symmetrical distances (ACPI spec SLIT rules allow it). However,
the distance debug message is dropped as it may be misleading (for a distance
which is later overwritten).

Some final notes on semantics:

- It is implied that it is the responsibility of the arch NUMA code to
  reset the NUMA distance map for an error in distance map parsing.

- It is the responsibility of the FW NUMA topology parsing (whether OF or
  ACPI) to enforce NUMA distance rules, and not arch NUMA code.

[1] Documents/devicetree/bindings/numa.txt
[2] https://www.spinics.net/lists/arm-kernel/msg683304.html

Cc: stable@vger.kernel.org # 4.7
Signed-off-by: John Garry <john.garry@huawei.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>

1 parent 6778be4

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rsa.c

/* RSA asymmetric public-key algorithm [RFC3447]
 *
 * Copyright (c) 2015, Intel Corporation
 * Authors: Tadeusz Struk <tadeusz.struk@intel.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */

#include <linux/module.h>
#include <linux/mpi.h>
#include <crypto/internal/rsa.h>
#include <crypto/internal/akcipher.h>
#include <crypto/akcipher.h>
#include <crypto/algapi.h>

struct rsa_mpi_key {
	MPI n;
	MPI e;
	MPI d;
};

/*
 * RSAEP function [RFC3447 sec 5.1.1]
 * c = m^e mod n;
 */
static int _rsa_enc(const struct rsa_mpi_key *key, MPI c, MPI m)
{
	/* (1) Validate 0 <= m < n */
	if (mpi_cmp_ui(m, 0) < 0 || mpi_cmp(m, key->n) >= 0)
		return -EINVAL;

	/* (2) c = m^e mod n */
	return mpi_powm(c, m, key->e, key->n);
}

/*
 * RSADP function [RFC3447 sec 5.1.2]
 * m = c^d mod n;
 */
static int _rsa_dec(const struct rsa_mpi_key *key, MPI m, MPI c)
{
	/* (1) Validate 0 <= c < n */
	if (mpi_cmp_ui(c, 0) < 0 || mpi_cmp(c, key->n) >= 0)
		return -EINVAL;

	/* (2) m = c^d mod n */
	return mpi_powm(m, c, key->d, key->n);
}

/*
 * RSASP1 function [RFC3447 sec 5.2.1]
 * s = m^d mod n
 */
static int _rsa_sign(const struct rsa_mpi_key *key, MPI s, MPI m)
{
	/* (1) Validate 0 <= m < n */
	if (mpi_cmp_ui(m, 0) < 0 || mpi_cmp(m, key->n) >= 0)
		return -EINVAL;

	/* (2) s = m^d mod n */
	return mpi_powm(s, m, key->d, key->n);
}

/*
 * RSAVP1 function [RFC3447 sec 5.2.2]
 * m = s^e mod n;
 */
static int _rsa_verify(const struct rsa_mpi_key *key, MPI m, MPI s)
{
	/* (1) Validate 0 <= s < n */
	if (mpi_cmp_ui(s, 0) < 0 || mpi_cmp(s, key->n) >= 0)
		return -EINVAL;

	/* (2) m = s^e mod n */
	return mpi_powm(m, s, key->e, key->n);
}

static inline struct rsa_mpi_key *rsa_get_key(struct crypto_akcipher *tfm)
{
	return akcipher_tfm_ctx(tfm);
}

static int rsa_enc(struct akcipher_request *req)
{
	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
	const struct rsa_mpi_key *pkey = rsa_get_key(tfm);
	MPI m, c = mpi_alloc(0);
	int ret = 0;
	int sign;

	if (!c)
		return -ENOMEM;

	if (unlikely(!pkey->n || !pkey->e)) {
		ret = -EINVAL;
		goto err_free_c;
	}

	ret = -ENOMEM;
	m = mpi_read_raw_from_sgl(req->src, req->src_len);
	if (!m)
		goto err_free_c;

	ret = _rsa_enc(pkey, c, m);
	if (ret)
		goto err_free_m;

	ret = mpi_write_to_sgl(c, req->dst, req->dst_len, &sign);
	if (ret)
		goto err_free_m;

	if (sign < 0)
		ret = -EBADMSG;

err_free_m:
	mpi_free(m);
err_free_c:
	mpi_free(c);
	return ret;
}

static int rsa_dec(struct akcipher_request *req)
{
	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
	const struct rsa_mpi_key *pkey = rsa_get_key(tfm);
	MPI c, m = mpi_alloc(0);
	int ret = 0;
	int sign;

	if (!m)
		return -ENOMEM;

	if (unlikely(!pkey->n || !pkey->d)) {
		ret = -EINVAL;
		goto err_free_m;
	}

	ret = -ENOMEM;
	c = mpi_read_raw_from_sgl(req->src, req->src_len);
	if (!c)
		goto err_free_m;

	ret = _rsa_dec(pkey, m, c);
	if (ret)
		goto err_free_c;

	ret = mpi_write_to_sgl(m, req->dst, req->dst_len, &sign);
	if (ret)
		goto err_free_c;

	if (sign < 0)
		ret = -EBADMSG;
err_free_c:
	mpi_free(c);
err_free_m:
	mpi_free(m);
	return ret;
}

static int rsa_sign(struct akcipher_request *req)
{
	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
	const struct rsa_mpi_key *pkey = rsa_get_key(tfm);
	MPI m, s = mpi_alloc(0);
	int ret = 0;
	int sign;

	if (!s)
		return -ENOMEM;

	if (unlikely(!pkey->n || !pkey->d)) {
		ret = -EINVAL;
		goto err_free_s;
	}

	ret = -ENOMEM;
	m = mpi_read_raw_from_sgl(req->src, req->src_len);
	if (!m)
		goto err_free_s;

	ret = _rsa_sign(pkey, s, m);
	if (ret)
		goto err_free_m;

	ret = mpi_write_to_sgl(s, req->dst, req->dst_len, &sign);
	if (ret)
		goto err_free_m;

	if (sign < 0)
		ret = -EBADMSG;

err_free_m:
	mpi_free(m);
err_free_s:
	mpi_free(s);
	return ret;
}

static int rsa_verify(struct akcipher_request *req)
{
	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
	const struct rsa_mpi_key *pkey = rsa_get_key(tfm);
	MPI s, m = mpi_alloc(0);
	int ret = 0;
	int sign;

	if (!m)
		return -ENOMEM;

	if (unlikely(!pkey->n || !pkey->e)) {
		ret = -EINVAL;
		goto err_free_m;
	}

	s = mpi_read_raw_from_sgl(req->src, req->src_len);
	if (!s) {
		ret = -ENOMEM;
		goto err_free_m;
	}

	ret = _rsa_verify(pkey, m, s);
	if (ret)
		goto err_free_s;

	ret = mpi_write_to_sgl(m, req->dst, req->dst_len, &sign);
	if (ret)
		goto err_free_s;

	if (sign < 0)
		ret = -EBADMSG;

err_free_s:
	mpi_free(s);
err_free_m:
	mpi_free(m);
	return ret;
}

static void rsa_free_mpi_key(struct rsa_mpi_key *key)
{
	mpi_free(key->d);
	mpi_free(key->e);
	mpi_free(key->n);
	key->d = NULL;
	key->e = NULL;
	key->n = NULL;
}

static int rsa_check_key_length(unsigned int len)
{
	switch (len) {
	case 512:
	case 1024:
	case 1536:
	case 2048:
	case 3072:
	case 4096:
		return 0;
	}

	return -EINVAL;
}

static int rsa_set_pub_key(struct crypto_akcipher *tfm, const void *key,
			   unsigned int keylen)
{
	struct rsa_mpi_key *mpi_key = akcipher_tfm_ctx(tfm);
	struct rsa_key raw_key = {0};
	int ret;

	/* Free the old MPI key if any */
	rsa_free_mpi_key(mpi_key);

	ret = rsa_parse_pub_key(&raw_key, key, keylen);
	if (ret)
		return ret;

	mpi_key->e = mpi_read_raw_data(raw_key.e, raw_key.e_sz);
	if (!mpi_key->e)
		goto err;

	mpi_key->n = mpi_read_raw_data(raw_key.n, raw_key.n_sz);
	if (!mpi_key->n)
		goto err;

	if (rsa_check_key_length(mpi_get_size(mpi_key->n) << 3)) {
		rsa_free_mpi_key(mpi_key);
		return -EINVAL;
	}

	return 0;

err:
	rsa_free_mpi_key(mpi_key);
	return -ENOMEM;
}

static int rsa_set_priv_key(struct crypto_akcipher *tfm, const void *key,
			    unsigned int keylen)
{
	struct rsa_mpi_key *mpi_key = akcipher_tfm_ctx(tfm);
	struct rsa_key raw_key = {0};
	int ret;

	/* Free the old MPI key if any */
	rsa_free_mpi_key(mpi_key);

	ret = rsa_parse_priv_key(&raw_key, key, keylen);
	if (ret)
		return ret;

	mpi_key->d = mpi_read_raw_data(raw_key.d, raw_key.d_sz);
	if (!mpi_key->d)
		goto err;

	mpi_key->e = mpi_read_raw_data(raw_key.e, raw_key.e_sz);
	if (!mpi_key->e)
		goto err;

	mpi_key->n = mpi_read_raw_data(raw_key.n, raw_key.n_sz);
	if (!mpi_key->n)
		goto err;

	if (rsa_check_key_length(mpi_get_size(mpi_key->n) << 3)) {
		rsa_free_mpi_key(mpi_key);
		return -EINVAL;
	}

	return 0;

err:
	rsa_free_mpi_key(mpi_key);
	return -ENOMEM;
}

static unsigned int rsa_max_size(struct crypto_akcipher *tfm)
{
	struct rsa_mpi_key *pkey = akcipher_tfm_ctx(tfm);

	return mpi_get_size(pkey->n);
}

static void rsa_exit_tfm(struct crypto_akcipher *tfm)
{
	struct rsa_mpi_key *pkey = akcipher_tfm_ctx(tfm);

	rsa_free_mpi_key(pkey);
}

static struct akcipher_alg rsa = {
	.encrypt = rsa_enc,
	.decrypt = rsa_dec,
	.sign = rsa_sign,
	.verify = rsa_verify,
	.set_priv_key = rsa_set_priv_key,
	.set_pub_key = rsa_set_pub_key,
	.max_size = rsa_max_size,
	.exit = rsa_exit_tfm,
	.base = {
		.cra_name = "rsa",
		.cra_driver_name = "rsa-generic",
		.cra_priority = 100,
		.cra_module = THIS_MODULE,
		.cra_ctxsize = sizeof(struct rsa_mpi_key),
	},
};

static int rsa_init(void)
{
	int err;

	err = crypto_register_akcipher(&rsa);
	if (err)
		return err;

	err = crypto_register_template(&rsa_pkcs1pad_tmpl);
	if (err) {
		crypto_unregister_akcipher(&rsa);
		return err;
	}

	return 0;
}

static void rsa_exit(void)
{
	crypto_unregister_template(&rsa_pkcs1pad_tmpl);
	crypto_unregister_akcipher(&rsa);
}

module_init(rsa_init);
module_exit(rsa_exit);
MODULE_ALIAS_CRYPTO("rsa");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("RSA generic algorithm");

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