Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 29c770a6 authored by Kees Cook's avatar Kees Cook Committed by Jordan Crouse
Browse files

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: default avatarKees Cook <keescook@chromium.org>
Acked-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Git-Commit: dc568baf9bd1d455de81a18bb68d555a3a9edc3f
Git-Repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Change-Id: Ic0dedbadfa868fda34dc1b2909c7605eafacc85a
Signed-off-by: default avatarJordan Crouse <jcrouse@codeaurora.org>
parent 62c191ea

drivers/block/cryptoloop.c

+11 −11
Original line number Diff line number Diff line
@@ -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 */
@@ -80,11 +80,11 @@ 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,

	err = crypto_sync_skcipher_setkey(tfm, info->lo_encrypt_key,

					  info->lo_encrypt_key_size);



	if (err != 0)
@@ -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;

	}