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crypto: omap-aes - 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

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Kees Cook 2018-09-18 19:10:58 -07:00 committed by Herbert Xu
parent f805f59d1e
commit e87f203ce6
2 changed files with 9 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
drivers/crypto/omap-aes.c
View File

@ -522,9 +522,9 @@ static int omap_aes_crypt(struct ablkcipher_request *req, unsigned long mode)
!!(mode & FLAGS_CBC));
if (req->nbytes < aes_fallback_sz) {
SKCIPHER_REQUEST_ON_STACK(subreq, ctx->fallback);
SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, ctx->fallback);
skcipher_request_set_tfm(subreq, ctx->fallback);
skcipher_request_set_sync_tfm(subreq, ctx->fallback);
skcipher_request_set_callback(subreq, req->base.flags, NULL,
NULL);
skcipher_request_set_crypt(subreq, req->src, req->dst,
@ -564,11 +564,11 @@ static int omap_aes_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
memcpy(ctx->key, key, keylen);
ctx->keylen = keylen;
crypto_skcipher_clear_flags(ctx->fallback, CRYPTO_TFM_REQ_MASK);
crypto_skcipher_set_flags(ctx->fallback, tfm->base.crt_flags &
crypto_sync_skcipher_clear_flags(ctx->fallback, CRYPTO_TFM_REQ_MASK);
crypto_sync_skcipher_set_flags(ctx->fallback, tfm->base.crt_flags &
CRYPTO_TFM_REQ_MASK);
ret = crypto_skcipher_setkey(ctx->fallback, key, keylen);
ret = crypto_sync_skcipher_setkey(ctx->fallback, key, keylen);
if (!ret)
return 0;
@ -613,11 +613,10 @@ static int omap_aes_crypt_req(struct crypto_engine *engine,
static int omap_aes_cra_init(struct crypto_tfm *tfm)
{
const char *name = crypto_tfm_alg_name(tfm);
const u32 flags = CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK;
struct omap_aes_ctx *ctx = crypto_tfm_ctx(tfm);
struct crypto_skcipher *blk;
struct crypto_sync_skcipher *blk;
blk = crypto_alloc_skcipher(name, 0, flags);
blk = crypto_alloc_sync_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK);
if (IS_ERR(blk))
return PTR_ERR(blk);
@ -667,7 +666,7 @@ static void omap_aes_cra_exit(struct crypto_tfm *tfm)
struct omap_aes_ctx *ctx = crypto_tfm_ctx(tfm);
if (ctx->fallback)
crypto_free_skcipher(ctx->fallback);
crypto_free_sync_skcipher(ctx->fallback);
ctx->fallback = NULL;
}

2
drivers/crypto/omap-aes.h
View File

@ -101,7 +101,7 @@ struct omap_aes_ctx {
int keylen;
u32 key[AES_KEYSIZE_256 / sizeof(u32)];
u8 nonce[4];
struct crypto_skcipher *fallback;
struct crypto_sync_skcipher *fallback;
struct crypto_skcipher *ctr;
};