Re: [PATCH 03/11] crypto: ahash: Remove VLA usage

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 





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@xxxxxxxxxxxxxx

Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

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; \


--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/dm-devel




[Index of Archives]     [DM Crypt]     [Fedora Desktop]     [ATA RAID]     [Fedora Marketing]     [Fedora Packaging]     [Fedora SELinux]     [Yosemite Discussion]     [KDE Users]     [Fedora Docs]

  Powered by Linux