Commit 8d605398 authored by Kees Cook's avatar Kees Cook Committed by Herbert Xu
Browse files

crypto: null - 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 5c525640

crypto/algif_aead.c

+6 −6
Original line number Diff line number Diff line
@@ -42,7 +42,7 @@ 


struct aead_tfm {

	struct crypto_aead *aead;

	struct crypto_skcipher *null_tfm;

	struct crypto_sync_skcipher *null_tfm;

};



static inline bool aead_sufficient_data(struct sock *sk)
@@ -75,13 +75,13 @@ static int aead_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) 
	return af_alg_sendmsg(sock, msg, size, ivsize);

}



static int crypto_aead_copy_sgl(struct crypto_skcipher *null_tfm,

static int crypto_aead_copy_sgl(struct crypto_sync_skcipher *null_tfm,

				struct scatterlist *src,

				struct scatterlist *dst, unsigned int len)

{

	SKCIPHER_REQUEST_ON_STACK(skreq, null_tfm);

	SYNC_SKCIPHER_REQUEST_ON_STACK(skreq, null_tfm);



	skcipher_request_set_tfm(skreq, null_tfm);

	skcipher_request_set_sync_tfm(skreq, null_tfm);

	skcipher_request_set_callback(skreq, CRYPTO_TFM_REQ_MAY_BACKLOG,

				      NULL, NULL);

	skcipher_request_set_crypt(skreq, src, dst, len, NULL);
@@ -99,7 +99,7 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg, 
	struct af_alg_ctx *ctx = ask->private;

	struct aead_tfm *aeadc = pask->private;

	struct crypto_aead *tfm = aeadc->aead;

	struct crypto_skcipher *null_tfm = aeadc->null_tfm;

	struct crypto_sync_skcipher *null_tfm = aeadc->null_tfm;

	unsigned int i, as = crypto_aead_authsize(tfm);

	struct af_alg_async_req *areq;

	struct af_alg_tsgl *tsgl, *tmp;
@@ -478,7 +478,7 @@ static void *aead_bind(const char *name, u32 type, u32 mask) 
{

	struct aead_tfm *tfm;

	struct crypto_aead *aead;

	struct crypto_skcipher *null_tfm;

	struct crypto_sync_skcipher *null_tfm;



	tfm = kzalloc(sizeof(*tfm), GFP_KERNEL);

	if (!tfm)

crypto/authenc.c

+4 −4
Original line number Diff line number Diff line
@@ -33,7 +33,7 @@ struct authenc_instance_ctx { 
struct crypto_authenc_ctx {

	struct crypto_ahash *auth;

	struct crypto_skcipher *enc;

	struct crypto_skcipher *null;

	struct crypto_sync_skcipher *null;

};



struct authenc_request_ctx {
@@ -185,9 +185,9 @@ static int crypto_authenc_copy_assoc(struct aead_request *req) 
{

	struct crypto_aead *authenc = crypto_aead_reqtfm(req);

	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);

	SKCIPHER_REQUEST_ON_STACK(skreq, ctx->null);

	SYNC_SKCIPHER_REQUEST_ON_STACK(skreq, ctx->null);



	skcipher_request_set_tfm(skreq, ctx->null);

	skcipher_request_set_sync_tfm(skreq, ctx->null);

	skcipher_request_set_callback(skreq, aead_request_flags(req),

				      NULL, NULL);

	skcipher_request_set_crypt(skreq, req->src, req->dst, req->assoclen,
@@ -318,7 +318,7 @@ static int crypto_authenc_init_tfm(struct crypto_aead *tfm) 
	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm);

	struct crypto_ahash *auth;

	struct crypto_skcipher *enc;

	struct crypto_skcipher *null;

	struct crypto_sync_skcipher *null;

	int err;



	auth = crypto_spawn_ahash(&ictx->auth);

crypto/authencesn.c

+4 −4
Original line number Diff line number Diff line
@@ -36,7 +36,7 @@ struct crypto_authenc_esn_ctx { 
	unsigned int reqoff;

	struct crypto_ahash *auth;

	struct crypto_skcipher *enc;

	struct crypto_skcipher *null;

	struct crypto_sync_skcipher *null;

};



struct authenc_esn_request_ctx {
@@ -183,9 +183,9 @@ static int crypto_authenc_esn_copy(struct aead_request *req, unsigned int len) 
{

	struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);

	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);

	SKCIPHER_REQUEST_ON_STACK(skreq, ctx->null);

	SYNC_SKCIPHER_REQUEST_ON_STACK(skreq, ctx->null);



	skcipher_request_set_tfm(skreq, ctx->null);

	skcipher_request_set_sync_tfm(skreq, ctx->null);

	skcipher_request_set_callback(skreq, aead_request_flags(req),

				      NULL, NULL);

	skcipher_request_set_crypt(skreq, req->src, req->dst, len, NULL);
@@ -341,7 +341,7 @@ static int crypto_authenc_esn_init_tfm(struct crypto_aead *tfm) 
	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(tfm);

	struct crypto_ahash *auth;

	struct crypto_skcipher *enc;

	struct crypto_skcipher *null;

	struct crypto_sync_skcipher *null;

	int err;



	auth = crypto_spawn_ahash(&ictx->auth);

crypto/crypto_null.c

+5 −6
Original line number Diff line number Diff line
@@ -26,7 +26,7 @@ 
#include <linux/string.h>



static DEFINE_MUTEX(crypto_default_null_skcipher_lock);

static struct crypto_skcipher *crypto_default_null_skcipher;

static struct crypto_sync_skcipher *crypto_default_null_skcipher;

static int crypto_default_null_skcipher_refcnt;



static int null_compress(struct crypto_tfm *tfm, const u8 *src,
@@ -152,16 +152,15 @@ MODULE_ALIAS_CRYPTO("compress_null"); 
MODULE_ALIAS_CRYPTO("digest_null");

MODULE_ALIAS_CRYPTO("cipher_null");



struct crypto_skcipher *crypto_get_default_null_skcipher(void)

struct crypto_sync_skcipher *crypto_get_default_null_skcipher(void)

{

	struct crypto_skcipher *tfm;

	struct crypto_sync_skcipher *tfm;



	mutex_lock(&crypto_default_null_skcipher_lock);

	tfm = crypto_default_null_skcipher;



	if (!tfm) {

		tfm = crypto_alloc_skcipher("ecb(cipher_null)",

					    0, CRYPTO_ALG_ASYNC);

		tfm = crypto_alloc_sync_skcipher("ecb(cipher_null)", 0, 0);

		if (IS_ERR(tfm))

			goto unlock;
@@ -181,7 +180,7 @@ void crypto_put_default_null_skcipher(void) 
{

	mutex_lock(&crypto_default_null_skcipher_lock);

	if (!--crypto_default_null_skcipher_refcnt) {

		crypto_free_skcipher(crypto_default_null_skcipher);

		crypto_free_sync_skcipher(crypto_default_null_skcipher);

		crypto_default_null_skcipher = NULL;

	}

	mutex_unlock(&crypto_default_null_skcipher_lock);

crypto/echainiv.c

+2 −2
Original line number Diff line number Diff line
@@ -47,9 +47,9 @@ static int echainiv_encrypt(struct aead_request *req) 
	info = req->iv;



	if (req->src != req->dst) {

		SKCIPHER_REQUEST_ON_STACK(nreq, ctx->sknull);

		SYNC_SKCIPHER_REQUEST_ON_STACK(nreq, ctx->sknull);



		skcipher_request_set_tfm(nreq, ctx->sknull);

		skcipher_request_set_sync_tfm(nreq, ctx->sknull);

		skcipher_request_set_callback(nreq, req->base.flags,

					      NULL, NULL);

		skcipher_request_set_crypt(nreq, req->src, req->dst,

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