Re: [PATCH v2 2/4] crypto: skcipher - Enforce non-ASYNC for on-stack requests
From: Herbert Xu <herbert@gondor.apana.org.au>
Date: 2018-09-07 03:43:07
Also in:
linux-arm-kernel, lkml
On Thu, Sep 06, 2018 at 03:58:52PM -0700, Kees Cook wrote:
quoted hunk ↗ jump to hunk
@@ -437,6 +442,12 @@ static inline struct crypto_skcipher *crypto_skcipher_reqtfm_check( { struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + if (req->__onstack) { + if (WARN_ON(crypto_skcipher_alg(tfm)->base.cra_flags & + CRYPTO_ALG_ASYNC)) + return ERR_PTR(-EINVAL); + }
Sorry but I don't like imposing a run-time check on everybody when stack-based requests are the odd ones out. If we're going to make this a run-time check (I'd much prefer a compile-time check, but I understand that this may involve too much churn), then please do it for stack-based request users only. Thanks, -- Email: Herbert Xu [off-list ref] Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt