linux/crypto/lz4hc.c
Dan Moulding f75f66683d crypto: comp - Use same definition of context alloc and free ops
In commit 42d9f6c774 ("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>
2025-09-20 20:21:03 +08:00

97 lines
2 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Cryptographic API.
*
* Copyright (c) 2013 Chanho Min <chanho.min@lge.com>
*/
#include <crypto/internal/scompress.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/lz4.h>
static void *lz4hc_alloc_ctx(void)
{
void *ctx;
ctx = vmalloc(LZ4HC_MEM_COMPRESS);
if (!ctx)
return ERR_PTR(-ENOMEM);
return ctx;
}
static void lz4hc_free_ctx(void *ctx)
{
vfree(ctx);
}
static int __lz4hc_compress_crypto(const u8 *src, unsigned int slen,
u8 *dst, unsigned int *dlen, void *ctx)
{
int out_len = LZ4_compress_HC(src, dst, slen,
*dlen, LZ4HC_DEFAULT_CLEVEL, ctx);
if (!out_len)
return -EINVAL;
*dlen = out_len;
return 0;
}
static int lz4hc_scompress(struct crypto_scomp *tfm, const u8 *src,
unsigned int slen, u8 *dst, unsigned int *dlen,
void *ctx)
{
return __lz4hc_compress_crypto(src, slen, dst, dlen, ctx);
}
static int __lz4hc_decompress_crypto(const u8 *src, unsigned int slen,
u8 *dst, unsigned int *dlen, void *ctx)
{
int out_len = LZ4_decompress_safe(src, dst, slen, *dlen);
if (out_len < 0)
return -EINVAL;
*dlen = out_len;
return 0;
}
static int lz4hc_sdecompress(struct crypto_scomp *tfm, const u8 *src,
unsigned int slen, u8 *dst, unsigned int *dlen,
void *ctx)
{
return __lz4hc_decompress_crypto(src, slen, dst, dlen, NULL);
}
static struct scomp_alg scomp = {
.streams = {
.alloc_ctx = lz4hc_alloc_ctx,
.free_ctx = lz4hc_free_ctx,
},
.compress = lz4hc_scompress,
.decompress = lz4hc_sdecompress,
.base = {
.cra_name = "lz4hc",
.cra_driver_name = "lz4hc-scomp",
.cra_module = THIS_MODULE,
}
};
static int __init lz4hc_mod_init(void)
{
return crypto_register_scomp(&scomp);
}
static void __exit lz4hc_mod_fini(void)
{
crypto_unregister_scomp(&scomp);
}
module_init(lz4hc_mod_init);
module_exit(lz4hc_mod_fini);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("LZ4HC Compression Algorithm");
MODULE_ALIAS_CRYPTO("lz4hc");