crypto: ahash - ensure statesize is non-zero

Unlike shash algorithms, ahash drivers must implement export
and import as their descriptors may contain hardware state and
cannot be exported as is.  Unfortunately some ahash drivers did
not provide them and end up causing crashes with algif_hash.

This patch adds a check to prevent these drivers from registering
ahash algorithms until they are fixed.

Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Russell King 2015-10-09 20:43:33 +01:00 committed by Herbert Xu
parent 92b279070d
commit 8996eafdcb

View File

@ -544,7 +544,8 @@ 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)
alg->halg.statesize > PAGE_SIZE / 8 ||
alg->halg.statesize == 0)
return -EINVAL;
base->cra_type = &crypto_ahash_type;