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>
This commit is contained in:
Kees Cook 2018-09-18 19:10:44 -07:00 committed by Herbert Xu
parent 88fe0b957f
commit dc568baf9b

View File

@ -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;
}