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	When building the kernel with clang, the compiler fails to build
security/apparmor/crypto.c with the following error:
    security/apparmor/crypto.c:36:8: error: fields must have a constant
    size: 'variable length array in structure' extension will never be
    supported
                    char ctx[crypto_shash_descsize(apparmor_tfm)];
                         ^
Since commit a0a77af141 ("crypto: LLVMLinux: Add macro to remove use
of VLAIS in crypto code"), include/crypto/hash.h defines
SHASH_DESC_ON_STACK to work around this issue. Use it in aa_calc_hash()
and aa_calc_profile_hash().
Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
		
	
			
		
			
				
	
	
		
			129 lines
		
	
	
	
		
			2.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			129 lines
		
	
	
	
		
			2.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * AppArmor security module
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 *
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 * This file contains AppArmor policy loading interface function definitions.
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 *
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 * Copyright 2013 Canonical Ltd.
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 *
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 * This program is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU General Public License as
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 * published by the Free Software Foundation, version 2 of the
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 * License.
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 *
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 * Fns to provide a checksum of policy that has been loaded this can be
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 * compared to userspace policy compiles to check loaded policy is what
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 * it should be.
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 */
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#include <crypto/hash.h>
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#include "include/apparmor.h"
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#include "include/crypto.h"
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static unsigned int apparmor_hash_size;
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static struct crypto_shash *apparmor_tfm;
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unsigned int aa_hash_size(void)
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{
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	return apparmor_hash_size;
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}
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char *aa_calc_hash(void *data, size_t len)
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{
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	SHASH_DESC_ON_STACK(desc, apparmor_tfm);
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	char *hash = NULL;
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	int error = -ENOMEM;
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	if (!apparmor_tfm)
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		return NULL;
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	hash = kzalloc(apparmor_hash_size, GFP_KERNEL);
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	if (!hash)
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		goto fail;
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	desc->tfm = apparmor_tfm;
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	desc->flags = 0;
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	error = crypto_shash_init(desc);
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	if (error)
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		goto fail;
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	error = crypto_shash_update(desc, (u8 *) data, len);
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	if (error)
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		goto fail;
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	error = crypto_shash_final(desc, hash);
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	if (error)
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		goto fail;
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	return hash;
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fail:
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	kfree(hash);
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	return ERR_PTR(error);
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}
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int aa_calc_profile_hash(struct aa_profile *profile, u32 version, void *start,
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			 size_t len)
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{
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	SHASH_DESC_ON_STACK(desc, apparmor_tfm);
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	int error = -ENOMEM;
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	__le32 le32_version = cpu_to_le32(version);
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	if (!aa_g_hash_policy)
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		return 0;
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	if (!apparmor_tfm)
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		return 0;
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	profile->hash = kzalloc(apparmor_hash_size, GFP_KERNEL);
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	if (!profile->hash)
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		goto fail;
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	desc->tfm = apparmor_tfm;
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	desc->flags = 0;
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	error = crypto_shash_init(desc);
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	if (error)
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		goto fail;
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	error = crypto_shash_update(desc, (u8 *) &le32_version, 4);
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	if (error)
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		goto fail;
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	error = crypto_shash_update(desc, (u8 *) start, len);
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	if (error)
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		goto fail;
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	error = crypto_shash_final(desc, profile->hash);
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	if (error)
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		goto fail;
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	return 0;
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fail:
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	kfree(profile->hash);
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	profile->hash = NULL;
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	return error;
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}
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static int __init init_profile_hash(void)
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{
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	struct crypto_shash *tfm;
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	if (!apparmor_initialized)
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		return 0;
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	tfm = crypto_alloc_shash("sha1", 0, CRYPTO_ALG_ASYNC);
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	if (IS_ERR(tfm)) {
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		int error = PTR_ERR(tfm);
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		AA_ERROR("failed to setup profile sha1 hashing: %d\n", error);
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		return error;
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	}
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	apparmor_tfm = tfm;
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	apparmor_hash_size = crypto_shash_digestsize(apparmor_tfm);
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	aa_info_message("AppArmor sha1 policy hashing enabled");
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	return 0;
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}
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late_initcall(init_profile_hash);
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