[PATCH crypto-next 14/23] crypto: null - Remove VLA usage of skcipher

From: Kees Cook
Date: Tue Sep 18 2018 - 22:12:06 EST


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@xxxxxxxxxxxxxx

Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
crypto/algif_aead.c | 12 ++++++------
crypto/authenc.c | 8 ++++----
crypto/authencesn.c | 8 ++++----
crypto/crypto_null.c | 11 +++++------
crypto/echainiv.c | 4 ++--
crypto/gcm.c | 8 ++++----
crypto/seqiv.c | 4 ++--
include/crypto/internal/geniv.h | 2 +-
include/crypto/null.h | 2 +-
9 files changed, 29 insertions(+), 30 deletions(-)

diff --git a/crypto/algif_aead.c b/crypto/algif_aead.c
index c40a8c7ee8ae..eb100a04ce9f 100644
--- a/crypto/algif_aead.c
+++ b/crypto/algif_aead.c
@@ -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)
diff --git a/crypto/authenc.c b/crypto/authenc.c
index 4fa8d40d947b..37f54d1b2f66 100644
--- a/crypto/authenc.c
+++ b/crypto/authenc.c
@@ -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);
diff --git a/crypto/authencesn.c b/crypto/authencesn.c
index 50b804747e20..80a25cc04aec 100644
--- a/crypto/authencesn.c
+++ b/crypto/authencesn.c
@@ -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);
diff --git a/crypto/crypto_null.c b/crypto/crypto_null.c
index 0959b268966c..0bae59922a80 100644
--- a/crypto/crypto_null.c
+++ b/crypto/crypto_null.c
@@ -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);
diff --git a/crypto/echainiv.c b/crypto/echainiv.c
index 45819e6015bf..77e607fdbfb7 100644
--- a/crypto/echainiv.c
+++ b/crypto/echainiv.c
@@ -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,
diff --git a/crypto/gcm.c b/crypto/gcm.c
index 0ad879e1f9b2..e438492db2ca 100644
--- a/crypto/gcm.c
+++ b/crypto/gcm.c
@@ -50,7 +50,7 @@ struct crypto_rfc4543_instance_ctx {

struct crypto_rfc4543_ctx {
struct crypto_aead *child;
- struct crypto_skcipher *null;
+ struct crypto_sync_skcipher *null;
u8 nonce[4];
};

@@ -1067,9 +1067,9 @@ static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc)
unsigned int authsize = crypto_aead_authsize(aead);
unsigned int nbytes = req->assoclen + req->cryptlen -
(enc ? 0 : authsize);
- SKCIPHER_REQUEST_ON_STACK(nreq, ctx->null);
+ SYNC_SKCIPHER_REQUEST_ON_STACK(nreq, ctx->null);

- skcipher_request_set_tfm(nreq, ctx->null);
+ skcipher_request_set_sync_tfm(nreq, ctx->null);
skcipher_request_set_callback(nreq, req->base.flags, NULL, NULL);
skcipher_request_set_crypt(nreq, req->src, req->dst, nbytes, NULL);

@@ -1093,7 +1093,7 @@ static int crypto_rfc4543_init_tfm(struct crypto_aead *tfm)
struct crypto_aead_spawn *spawn = &ictx->aead;
struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm);
struct crypto_aead *aead;
- struct crypto_skcipher *null;
+ struct crypto_sync_skcipher *null;
unsigned long align;
int err = 0;

diff --git a/crypto/seqiv.c b/crypto/seqiv.c
index 39dbf2f7e5f5..64a412be255e 100644
--- a/crypto/seqiv.c
+++ b/crypto/seqiv.c
@@ -73,9 +73,9 @@ static int seqiv_aead_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,
diff --git a/include/crypto/internal/geniv.h b/include/crypto/internal/geniv.h
index 2bcfb931bc5b..71be24cd59bd 100644
--- a/include/crypto/internal/geniv.h
+++ b/include/crypto/internal/geniv.h
@@ -20,7 +20,7 @@
struct aead_geniv_ctx {
spinlock_t lock;
struct crypto_aead *child;
- struct crypto_skcipher *sknull;
+ struct crypto_sync_skcipher *sknull;
u8 salt[] __attribute__ ((aligned(__alignof__(u32))));
};

diff --git a/include/crypto/null.h b/include/crypto/null.h
index 15aeef6e30ef..0ef577cc00e3 100644
--- a/include/crypto/null.h
+++ b/include/crypto/null.h
@@ -9,7 +9,7 @@
#define NULL_DIGEST_SIZE 0
#define NULL_IV_SIZE 0

-struct crypto_skcipher *crypto_get_default_null_skcipher(void);
+struct crypto_sync_skcipher *crypto_get_default_null_skcipher(void);
void crypto_put_default_null_skcipher(void);

#endif
--
2.17.1