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Revision 592025a03b34927f35852058c933ffcd7c500321 authored by Jacob Keller on 14 November 2019, 18:45:01 UTC, committed by David S. Miller on 15 November 2019, 20:48:32 UTC 
renesas: reject unsupported external timestamp flags
 
Fix the renesas PTP support to explicitly reject any future flags that
get added to the external timestamp request ioctl.

In order to maintain currently functioning code, this patch accepts all
three current flags. This is because the PTP_RISING_EDGE and
PTP_FALLING_EDGE flags have unclear semantics and each driver seems to
have interpreted them slightly differently.

Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Richard Cochran <richardcochran@gmail.com>
Reviewed-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent 2e0645a
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dh_helper.c 
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (c) 2016, Intel Corporation
 * Authors: Salvatore Benedetto <salvatore.benedetto@intel.com>
 */
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/err.h>
#include <linux/string.h>
#include <crypto/dh.h>
#include <crypto/kpp.h>

#define DH_KPP_SECRET_MIN_SIZE (sizeof(struct kpp_secret) + 4 * sizeof(int))

static inline u8 *dh_pack_data(u8 *dst, u8 *end, const void *src, size_t size)
{
	if (!dst || size > end - dst)
		return NULL;
	memcpy(dst, src, size);
	return dst + size;
}

static inline const u8 *dh_unpack_data(void *dst, const void *src, size_t size)
{
	memcpy(dst, src, size);
	return src + size;
}

static inline unsigned int dh_data_size(const struct dh *p)
{
	return p->key_size + p->p_size + p->q_size + p->g_size;
}

unsigned int crypto_dh_key_len(const struct dh *p)
{
	return DH_KPP_SECRET_MIN_SIZE + dh_data_size(p);
}
EXPORT_SYMBOL_GPL(crypto_dh_key_len);

int crypto_dh_encode_key(char *buf, unsigned int len, const struct dh *params)
{
	u8 *ptr = buf;
	u8 * const end = ptr + len;
	struct kpp_secret secret = {
		.type = CRYPTO_KPP_SECRET_TYPE_DH,
		.len = len
	};

	if (unlikely(!len))
		return -EINVAL;

	ptr = dh_pack_data(ptr, end, &secret, sizeof(secret));
	ptr = dh_pack_data(ptr, end, &params->key_size,
			   sizeof(params->key_size));
	ptr = dh_pack_data(ptr, end, &params->p_size, sizeof(params->p_size));
	ptr = dh_pack_data(ptr, end, &params->q_size, sizeof(params->q_size));
	ptr = dh_pack_data(ptr, end, &params->g_size, sizeof(params->g_size));
	ptr = dh_pack_data(ptr, end, params->key, params->key_size);
	ptr = dh_pack_data(ptr, end, params->p, params->p_size);
	ptr = dh_pack_data(ptr, end, params->q, params->q_size);
	ptr = dh_pack_data(ptr, end, params->g, params->g_size);
	if (ptr != end)
		return -EINVAL;
	return 0;
}
EXPORT_SYMBOL_GPL(crypto_dh_encode_key);

int crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params)
{
	const u8 *ptr = buf;
	struct kpp_secret secret;

	if (unlikely(!buf || len < DH_KPP_SECRET_MIN_SIZE))
		return -EINVAL;

	ptr = dh_unpack_data(&secret, ptr, sizeof(secret));
	if (secret.type != CRYPTO_KPP_SECRET_TYPE_DH)
		return -EINVAL;

	ptr = dh_unpack_data(&params->key_size, ptr, sizeof(params->key_size));
	ptr = dh_unpack_data(&params->p_size, ptr, sizeof(params->p_size));
	ptr = dh_unpack_data(&params->q_size, ptr, sizeof(params->q_size));
	ptr = dh_unpack_data(&params->g_size, ptr, sizeof(params->g_size));
	if (secret.len != crypto_dh_key_len(params))
		return -EINVAL;

	/*
	 * Don't permit the buffer for 'key' or 'g' to be larger than 'p', since
	 * some drivers assume otherwise.
	 */
	if (params->key_size > params->p_size ||
	    params->g_size > params->p_size || params->q_size > params->p_size)
		return -EINVAL;

	/* Don't allocate memory. Set pointers to data within
	 * the given buffer
	 */
	params->key = (void *)ptr;
	params->p = (void *)(ptr + params->key_size);
	params->q = (void *)(ptr + params->key_size + params->p_size);
	params->g = (void *)(ptr + params->key_size + params->p_size +
			     params->q_size);

	/*
	 * Don't permit 'p' to be 0.  It's not a prime number, and it's subject
	 * to corner cases such as 'mod 0' being undefined or
	 * crypto_kpp_maxsize() returning 0.
	 */
	if (memchr_inv(params->p, 0, params->p_size) == NULL)
		return -EINVAL;

	/* It is permissible to not provide Q. */
	if (params->q_size == 0)
		params->q = NULL;

	return 0;
}
EXPORT_SYMBOL_GPL(crypto_dh_decode_key);
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