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Commit e87f203c authored by Kees Cook's avatar Kees Cook Committed by Herbert Xu
Browse files

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: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent f805f59d

drivers/crypto/omap-aes.c

+8 −9
Original line number Diff line number Diff line
@@ -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;

}

drivers/crypto/omap-aes.h

+1 −1
Original line number Diff line number Diff line
@@ -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;

};