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x86/fpu: Remove VLA usage of skcipher 

In the quest to remove all stack VLA usage from the kernel[1], this
replaces struct crypto_skcipher and SKCIPHER_REQUEST_ON_STACK() usage
with struct crypto_sync_skcipher and SYNC_SKCIPHER_REQUEST_ON_STACK(),
which uses a fixed stack size.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com

Cc: x86@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
hifive-unleashed-5.1
Kees Cook 2018-09-18 19:10:43 -07:00 committed by Herbert Xu
parent 531fa5d620
commit 88fe0b957f
1 changed files with 16 additions and 14 deletions
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30
arch/x86/crypto/fpu.c
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@ -20,21 +20,23 @@
#include <asm/fpu/api.h>
struct crypto_fpu_ctx {
struct crypto_skcipher *child;
struct crypto_sync_skcipher *child;
};
static int crypto_fpu_setkey(struct crypto_skcipher *parent, const u8 *key,
unsigned int keylen)
{
struct crypto_fpu_ctx *ctx = crypto_skcipher_ctx(parent);
struct crypto_skcipher *child = ctx->child;
struct crypto_sync_skcipher *child = ctx->child;
int err;
crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
crypto_sync_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
crypto_sync_skcipher_set_flags(child,
crypto_skcipher_get_flags(parent) &
CRYPTO_TFM_REQ_MASK);
err = crypto_skcipher_setkey(child, key, keylen);
crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) &
err = crypto_sync_skcipher_setkey(child, key, keylen);
crypto_skcipher_set_flags(parent,
crypto_sync_skcipher_get_flags(child) &
CRYPTO_TFM_RES_MASK);
return err;
}
@ -43,11 +45,11 @@ static int crypto_fpu_encrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_fpu_ctx *ctx = crypto_skcipher_ctx(tfm);
struct crypto_skcipher *child = ctx->child;
SKCIPHER_REQUEST_ON_STACK(subreq, child);
struct crypto_sync_skcipher *child = ctx->child;
SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, child);
int err;
skcipher_request_set_tfm(subreq, child);
skcipher_request_set_sync_tfm(subreq, child);
skcipher_request_set_callback(subreq, 0, NULL, NULL);
skcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
req->iv);
@ -64,11 +66,11 @@ static int crypto_fpu_decrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_fpu_ctx *ctx = crypto_skcipher_ctx(tfm);
struct crypto_skcipher *child = ctx->child;
SKCIPHER_REQUEST_ON_STACK(subreq, child);
struct crypto_sync_skcipher *child = ctx->child;
SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, child);
int err;
skcipher_request_set_tfm(subreq, child);
skcipher_request_set_sync_tfm(subreq, child);
skcipher_request_set_callback(subreq, 0, NULL, NULL);
skcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
req->iv);
@ -93,7 +95,7 @@ static int crypto_fpu_init_tfm(struct crypto_skcipher *tfm)
if (IS_ERR(cipher))
return PTR_ERR(cipher);
ctx->child = cipher;
ctx->child = (struct crypto_sync_skcipher *)cipher;
return 0;
}
@ -102,7 +104,7 @@ static void crypto_fpu_exit_tfm(struct crypto_skcipher *tfm)
{
struct crypto_fpu_ctx *ctx = crypto_skcipher_ctx(tfm);
crypto_free_skcipher(ctx->child);
crypto_free_sync_skcipher(ctx->child);
}
static void crypto_fpu_free(struct skcipher_instance *inst)