block: cryptoloop: 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
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/drivers/block/cryptoloop.c b/drivers/block/cryptoloop.c
index 7033a4b..254ee7d 100644
--- a/drivers/block/cryptoloop.c
+++ b/drivers/block/cryptoloop.c
@@ -45,7 +45,7 @@ cryptoloop_init(struct loop_device *lo, const struct loop_info64 *info)
char cms[LO_NAME_SIZE]; /* cipher-mode string */
char *mode;
char *cmsp = cms; /* c-m string pointer */
- struct crypto_skcipher *tfm;
+ struct crypto_sync_skcipher *tfm;
/* encryption breaks for non sector aligned offsets */
@@ -80,13 +80,13 @@ cryptoloop_init(struct loop_device *lo, const struct loop_info64 *info)
*cmsp++ = ')';
*cmsp = 0;
- tfm = crypto_alloc_skcipher(cms, 0, CRYPTO_ALG_ASYNC);
+ tfm = crypto_alloc_sync_skcipher(cms, 0, 0);
if (IS_ERR(tfm))
return PTR_ERR(tfm);
- err = crypto_skcipher_setkey(tfm, info->lo_encrypt_key,
- info->lo_encrypt_key_size);
-
+ err = crypto_sync_skcipher_setkey(tfm, info->lo_encrypt_key,
+ info->lo_encrypt_key_size);
+
if (err != 0)
goto out_free_tfm;
@@ -94,7 +94,7 @@ cryptoloop_init(struct loop_device *lo, const struct loop_info64 *info)
return 0;
out_free_tfm:
- crypto_free_skcipher(tfm);
+ crypto_free_sync_skcipher(tfm);
out:
return err;
@@ -109,8 +109,8 @@ cryptoloop_transfer(struct loop_device *lo, int cmd,
struct page *loop_page, unsigned loop_off,
int size, sector_t IV)
{
- struct crypto_skcipher *tfm = lo->key_data;
- SKCIPHER_REQUEST_ON_STACK(req, tfm);
+ struct crypto_sync_skcipher *tfm = lo->key_data;
+ SYNC_SKCIPHER_REQUEST_ON_STACK(req, tfm);
struct scatterlist sg_out;
struct scatterlist sg_in;
@@ -119,7 +119,7 @@ cryptoloop_transfer(struct loop_device *lo, int cmd,
unsigned in_offs, out_offs;
int err;
- skcipher_request_set_tfm(req, tfm);
+ skcipher_request_set_sync_tfm(req, tfm);
skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP,
NULL, NULL);
@@ -175,9 +175,9 @@ cryptoloop_ioctl(struct loop_device *lo, int cmd, unsigned long arg)
static int
cryptoloop_release(struct loop_device *lo)
{
- struct crypto_skcipher *tfm = lo->key_data;
+ struct crypto_sync_skcipher *tfm = lo->key_data;
if (tfm != NULL) {
- crypto_free_skcipher(tfm);
+ crypto_free_sync_skcipher(tfm);
lo->key_data = NULL;
return 0;
}