From: Gary R Hook <ghook@amd.com>
Subject: Re: Remaining crypto API regressions with CONFIG_VMAP_STACK
Date: Mon, 12 Dec 2016 12:45:18 -0600
Message-ID: <1747e6e9-35dc-48cc-7345-4f0412ba2521@amd.com>
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 <CALCETrWfa5VJQNu3XjeFhF0cDFWF+M-dPwsT_7dzO5YSxsneGg@mail.gmail.com>
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Cc: <linux-crypto@vger.kernel.org>, "linux-kernel@vger.kernel.org"
	<linux-kernel@vger.kernel.org>, "linux-mm@kvack.org" <linux-mm@kvack.org>,
	"kernel-hardening@lists.openwall.com" <kernel-hardening@lists.openwall.com>,
	Herbert Xu <herbert@gondor.apana.org.au>, Andrew Lutomirski
	<luto@kernel.org>, Stephan Mueller <smueller@chronox.de>
To: Andy Lutomirski <luto@amacapital.net>, Eric Biggers <ebiggers3@gmail.com>
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On 12/12/2016 12:34 PM, Andy Lutomirski wrote:

<...snip...>

>
> I have a patch to make these depend on !VMAP_STACK.
>
>>         drivers/crypto/ccp/ccp-crypto-aes-cmac.c:105,119,142
>>         drivers/crypto/ccp/ccp-crypto-sha.c:95,109,124
>>         drivers/crypto/ccp/ccp-crypto-aes-xts.c:162
>>         drivers/crypto/ccp/ccp-crypto-aes.c:94
>
> According to Herbert, these are fine.  I'm personally less convinced
> since I'm very confused as to what "async" means in the crypto code,
> but I'm going to leave these alone.

I went back through the code, and AFAICT every argument to sg_init_one() in
the above-cited files is a buffer that is part of the request context. Which
is allocated by the crypto framework, and therefore will never be on the 
stack.
Right?

I don't (as yet) see a need for any patch to these. Someone correct me 
if I'm
missing something.

<...snip...>

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