Commit 3a58c231 authored by Herbert Xu's avatar Herbert Xu
Browse files

crypto: cryptd - Use request context instead of stack for sub-request 



cryptd is buggy as it tries to use sync_skcipher without going
through the proper sync_skcipher interface.  In fact it doesn't
even need sync_skcipher since it's already a proper skcipher and
can easily access the request context instead of using something
off the stack.

Fixes: 36b3875a ("crypto: cryptd - Remove VLA usage of skcipher")
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 824db5cd

crypto/cryptd.c

+19 −17
Original line number Diff line number Diff line
@@ -68,11 +68,12 @@ struct aead_instance_ctx { 


struct cryptd_skcipher_ctx {

	refcount_t refcnt;

	struct crypto_sync_skcipher *child;

	struct crypto_skcipher *child;

};



struct cryptd_skcipher_request_ctx {

	crypto_completion_t complete;

	struct skcipher_request req;

};



struct cryptd_hash_ctx {
@@ -227,13 +228,13 @@ static int cryptd_skcipher_setkey(struct crypto_skcipher *parent, 
				  const u8 *key, unsigned int keylen)

{

	struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(parent);

	struct crypto_sync_skcipher *child = ctx->child;

	struct crypto_skcipher *child = ctx->child;



	crypto_sync_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);

	crypto_sync_skcipher_set_flags(child,

	crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);

	crypto_skcipher_set_flags(child,

				  crypto_skcipher_get_flags(parent) &

				  CRYPTO_TFM_REQ_MASK);

	return crypto_sync_skcipher_setkey(child, key, keylen);

	return crypto_skcipher_setkey(child, key, keylen);

}



static void cryptd_skcipher_complete(struct skcipher_request *req, int err)
@@ -258,13 +259,13 @@ static void cryptd_skcipher_encrypt(struct crypto_async_request *base, 
	struct cryptd_skcipher_request_ctx *rctx = skcipher_request_ctx(req);

	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);

	struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);

	struct crypto_sync_skcipher *child = ctx->child;

	SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, child);

	struct skcipher_request *subreq = &rctx->req;

	struct crypto_skcipher *child = ctx->child;



	if (unlikely(err == -EINPROGRESS))

		goto out;



	skcipher_request_set_sync_tfm(subreq, child);

	skcipher_request_set_tfm(subreq, child);

	skcipher_request_set_callback(subreq, CRYPTO_TFM_REQ_MAY_SLEEP,

				      NULL, NULL);

	skcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
@@ -286,13 +287,13 @@ static void cryptd_skcipher_decrypt(struct crypto_async_request *base, 
	struct cryptd_skcipher_request_ctx *rctx = skcipher_request_ctx(req);

	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);

	struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);

	struct crypto_sync_skcipher *child = ctx->child;

	SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, child);

	struct skcipher_request *subreq = &rctx->req;

	struct crypto_skcipher *child = ctx->child;



	if (unlikely(err == -EINPROGRESS))

		goto out;



	skcipher_request_set_sync_tfm(subreq, child);

	skcipher_request_set_tfm(subreq, child);

	skcipher_request_set_callback(subreq, CRYPTO_TFM_REQ_MAY_SLEEP,

				      NULL, NULL);

	skcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
@@ -343,9 +344,10 @@ static int cryptd_skcipher_init_tfm(struct crypto_skcipher *tfm) 
	if (IS_ERR(cipher))

		return PTR_ERR(cipher);



	ctx->child = (struct crypto_sync_skcipher *)cipher;

	ctx->child = cipher;

	crypto_skcipher_set_reqsize(

		tfm, sizeof(struct cryptd_skcipher_request_ctx));

		tfm, sizeof(struct cryptd_skcipher_request_ctx) +

		     crypto_skcipher_reqsize(cipher));

	return 0;

}
@@ -353,7 +355,7 @@ static void cryptd_skcipher_exit_tfm(struct crypto_skcipher *tfm) 
{

	struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);



	crypto_free_sync_skcipher(ctx->child);

	crypto_free_skcipher(ctx->child);

}



static void cryptd_skcipher_free(struct skcipher_instance *inst)
@@ -931,7 +933,7 @@ struct crypto_skcipher *cryptd_skcipher_child(struct cryptd_skcipher *tfm) 
{

	struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(&tfm->base);



	return &ctx->child->base;

	return ctx->child;

}

EXPORT_SYMBOL_GPL(cryptd_skcipher_child);