On Sun, Feb 26, 2017 at 10:03:18PM -0300, Marcelo Henrique Cerri wrote:
> When requesting a fallback algorithm, we should propagate the
> NEED_FALLBACK bit when search for the underlying algorithm.
>
> This will prevents drivers from allocating unnecessary fallbacks that
> are never called. For instance, currently the vmx-crypto driver will use
> the following chain of calls when calling the fallback implementation:
>
> p8_aes_cbc -> cbc(p8_aes) -> aes-generic
>
> However p8_aes will always delegate its calls to aes-generic. With this
> patch, p8_aes_cbc will be able to use cbc(aes-generic) directly as its
> fallback. The same applies to aes_s390.
>
> Signed-off-by: Marcelo Henrique Cerri <marcelo.cerri@xxxxxxxxxxxxx>
> ---
> crypto/cbc.c | 20 ++++++++++++++------
> 1 file changed, 14 insertions(+), 6 deletions(-)
>
> diff --git a/crypto/cbc.c b/crypto/cbc.c
> index bc160a3..7147842 100644
> --- a/crypto/cbc.c
> +++ b/crypto/cbc.c
> @@ -108,24 +108,32 @@ static void crypto_cbc_free(struct skcipher_instance *inst)
> static int crypto_cbc_create(struct crypto_template *tmpl, struct rtattr **tb)
> {
> struct skcipher_instance *inst;
> + struct crypto_attr_type *algt;
> struct crypto_spawn *spawn;
> struct crypto_alg *alg;
> + u32 mask;
> int err;
>
> err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER);
> if (err)
> return err;
>
> + algt = crypto_get_attr_type(tb);
> + if (IS_ERR(algt))
> + return PTR_ERR(algt);
> +
> + mask = CRYPTO_ALG_TYPE_MASK |
> + crypto_requires_off(algt->type, algt->mask,
> + CRYPTO_ALG_NEED_FALLBACK);
> +
> + alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER, mask);
> + if (IS_ERR(alg))
> + return PTR_ERR(alg);
> +
> inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
> if (!inst)
> return -ENOMEM;
You're leaking alg if the kzalloc of inst fails. Easiest fix
would be to do crypto_get_attr_alg after the kzalloc as is the
status quo.
Thanks,
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
