Messages in this thread | | | Subject | Re: [PATCH 03/11] crypto: ahash: Remove VLA usage | From | Christophe Leroy <> | Date | Wed, 20 Jun 2018 20:13:01 +0000 |
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On 06/20/2018 07:04 PM, Kees Cook wrote: > In the quest to remove all stack VLA usage from the kernel[1], this > introduces max size macros for ahash, as already done for shash, and > adjust the crypto user to max state size. > > [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com > > Signed-off-by: Kees Cook <keescook@chromium.org>
I get:
crypto/algif_hash.c: In function ‘hash_accept’: crypto/algif_hash.c:276:1: warning: the frame size of 2048 bytes is larger than 1024 bytes [-Wframe-larger-than=]
Christophe
> --- > crypto/ahash.c | 4 ++-- > crypto/algif_hash.c | 2 +- > include/crypto/hash.h | 3 +++ > 3 files changed, 6 insertions(+), 3 deletions(-) > > diff --git a/crypto/ahash.c b/crypto/ahash.c > index a64c143165b1..6435bdbe42fd 100644 > --- a/crypto/ahash.c > +++ b/crypto/ahash.c > @@ -550,8 +550,8 @@ static int ahash_prepare_alg(struct ahash_alg *alg) > { > struct crypto_alg *base = &alg->halg.base; > > - if (alg->halg.digestsize > PAGE_SIZE / 8 || > - alg->halg.statesize > PAGE_SIZE / 8 || > + if (alg->halg.digestsize > AHASH_MAX_DIGESTSIZE || > + alg->halg.statesize > AHASH_MAX_STATESIZE || > alg->halg.statesize == 0) > return -EINVAL; > > diff --git a/crypto/algif_hash.c b/crypto/algif_hash.c > index bfcf595fd8f9..8974ee8ebead 100644 > --- a/crypto/algif_hash.c > +++ b/crypto/algif_hash.c > @@ -239,7 +239,7 @@ static int hash_accept(struct socket *sock, struct socket *newsock, int flags, > struct alg_sock *ask = alg_sk(sk); > struct hash_ctx *ctx = ask->private; > struct ahash_request *req = &ctx->req; > - char state[crypto_ahash_statesize(crypto_ahash_reqtfm(req)) ? : 1]; > + char state[AHASH_MAX_STATESIZE]; > struct sock *sk2; > struct alg_sock *ask2; > struct hash_ctx *ctx2; > diff --git a/include/crypto/hash.h b/include/crypto/hash.h > index 308aad8bf523..b9df568dc98e 100644 > --- a/include/crypto/hash.h > +++ b/include/crypto/hash.h > @@ -64,6 +64,9 @@ struct ahash_request { > void *__ctx[] CRYPTO_MINALIGN_ATTR; > }; > > +#define AHASH_MAX_DIGESTSIZE (PAGE_SIZE / 8) > +#define AHASH_MAX_STATESIZE (PAGE_SIZE / 8) > + > #define AHASH_REQUEST_ON_STACK(name, ahash) \ > char __##name##_desc[sizeof(struct ahash_request) + \ > crypto_ahash_reqsize(ahash)] CRYPTO_MINALIGN_ATTR; \ >
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