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Commit 89027579 authored by Herbert Xu's avatar Herbert Xu
Browse files

crypto: xts - Propagate NEED_FALLBACK bit 



When we're used as a fallback algorithm, we should propagate
the NEED_FALLBACK bit when searching for the underlying ECB mode.

This just happens to fix a hang too because otherwise the search
may end up loading the same module that triggered this XTS creation.

Cc: stable@vger.kernel.org #4.10
Fixes: f1c131b4 ("crypto: xts - Convert to skcipher")
Reported-by: default avatarHarald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 016df0ab

crypto/xts.c

+8 −6
Original line number Diff line number Diff line
@@ -463,6 +463,7 @@ static int create(struct crypto_template *tmpl, struct rtattr **tb) 
	struct xts_instance_ctx *ctx;

	struct skcipher_alg *alg;

	const char *cipher_name;

	u32 mask;

	int err;



	algt = crypto_get_attr_type(tb);
@@ -483,18 +484,19 @@ static int create(struct crypto_template *tmpl, struct rtattr **tb) 
	ctx = skcipher_instance_ctx(inst);



	crypto_set_skcipher_spawn(&ctx->spawn, skcipher_crypto_instance(inst));

	err = crypto_grab_skcipher(&ctx->spawn, cipher_name, 0,

				   crypto_requires_sync(algt->type,

							algt->mask));



	mask = crypto_requires_off(algt->type, algt->mask,

				   CRYPTO_ALG_NEED_FALLBACK |

				   CRYPTO_ALG_ASYNC);



	err = crypto_grab_skcipher(&ctx->spawn, cipher_name, 0, mask);

	if (err == -ENOENT) {

		err = -ENAMETOOLONG;

		if (snprintf(ctx->name, CRYPTO_MAX_ALG_NAME, "ecb(%s)",

			     cipher_name) >= CRYPTO_MAX_ALG_NAME)

			goto err_free_inst;



		err = crypto_grab_skcipher(&ctx->spawn, ctx->name, 0,

					   crypto_requires_sync(algt->type,

								algt->mask));

		err = crypto_grab_skcipher(&ctx->spawn, ctx->name, 0, mask);

	}



	if (err)