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f75f66683d
In commit42d9f6c774("crypto: acomp - Move scomp stream allocation code into acomp"), the crypto_acomp_streams struct was made to rely on having the alloc_ctx and free_ctx operations defined in the same order as the scomp_alg struct. But in that same commit, the alloc_ctx and free_ctx members of scomp_alg may be randomized by structure layout randomization, since they are contained in a pure ops structure (containing only function pointers). If the pointers within scomp_alg are randomized, but those in crypto_acomp_streams are not, then the order may no longer match. This fixes the problem by removing the union from scomp_alg so that both crypto_acomp_streams and scomp_alg will share the same definition of alloc_ctx and free_ctx, ensuring they will always have the same layout. Signed-off-by: Dan Moulding <dan@danm.net> Suggested-by: Herbert Xu <herbert@gondor.apana.org.au> Fixes:42d9f6c774("crypto: acomp - Move scomp stream allocation code into acomp") Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
87 lines
2.3 KiB
C
87 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Cryptographic API for the 842 software compression algorithm.
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*
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* Copyright (C) IBM Corporation, 2011-2015
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*
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* Original Authors: Robert Jennings <rcj@linux.vnet.ibm.com>
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* Seth Jennings <sjenning@linux.vnet.ibm.com>
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*
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* Rewrite: Dan Streetman <ddstreet@ieee.org>
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*
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* This is the software implementation of compression and decompression using
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* the 842 format. This uses the software 842 library at lib/842/ which is
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* only a reference implementation, and is very, very slow as compared to other
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* software compressors. You probably do not want to use this software
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* compression. If you have access to the PowerPC 842 compression hardware, you
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* want to use the 842 hardware compression interface, which is at:
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* drivers/crypto/nx/nx-842-crypto.c
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*/
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#include <crypto/internal/scompress.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/sw842.h>
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static void *crypto842_alloc_ctx(void)
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{
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void *ctx;
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ctx = kmalloc(SW842_MEM_COMPRESS, GFP_KERNEL);
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if (!ctx)
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return ERR_PTR(-ENOMEM);
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return ctx;
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}
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static void crypto842_free_ctx(void *ctx)
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{
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kfree(ctx);
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}
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static int crypto842_scompress(struct crypto_scomp *tfm,
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const u8 *src, unsigned int slen,
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u8 *dst, unsigned int *dlen, void *ctx)
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{
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return sw842_compress(src, slen, dst, dlen, ctx);
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}
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static int crypto842_sdecompress(struct crypto_scomp *tfm,
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const u8 *src, unsigned int slen,
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u8 *dst, unsigned int *dlen, void *ctx)
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{
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return sw842_decompress(src, slen, dst, dlen);
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}
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static struct scomp_alg scomp = {
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.streams = {
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.alloc_ctx = crypto842_alloc_ctx,
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.free_ctx = crypto842_free_ctx,
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},
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.compress = crypto842_scompress,
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.decompress = crypto842_sdecompress,
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.base = {
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.cra_name = "842",
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.cra_driver_name = "842-scomp",
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.cra_priority = 100,
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.cra_module = THIS_MODULE,
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}
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};
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static int __init crypto842_mod_init(void)
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{
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return crypto_register_scomp(&scomp);
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}
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module_init(crypto842_mod_init);
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static void __exit crypto842_mod_exit(void)
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{
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crypto_unregister_scomp(&scomp);
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}
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module_exit(crypto842_mod_exit);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("842 Software Compression Algorithm");
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MODULE_ALIAS_CRYPTO("842");
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MODULE_ALIAS_CRYPTO("842-generic");
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MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");
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