From: Herbert Xu <herbert@gondor.apana.org.au>
Subject: Re: [PATCH 2/2] crypto: skcipher: Remove VLA usage for
 SKCIPHER_REQUEST_ON_STACK
Date: Thu, 6 Sep 2018 16:51:00 +0800
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Cc: Gilad Ben-Yossef <gilad@benyossef.com>,
        Kees Cook <keescook@chromium.org>,
        Eric Biggers <ebiggers@google.com>,
        Antoine Tenart <antoine.tenart@bootlin.com>,
        Boris Brezillon <boris.brezillon@bootlin.com>,
        Arnaud Ebalard <arno@natisbad.org>,
        Corentin Labbe <clabbe.montjoie@gmail.com>,
        Maxime Ripard <maxime.ripard@bootlin.com>,
        Chen-Yu Tsai <wens@csie.org>,
        Christian Lamparter <chunkeey@gmail.com>,
        Philippe Ombredanne <pombredanne@nexb.com>,
        Jonathan Cameron <Jonathan.Cameron@huawei.com>,
        "open list:HARDWARE RANDOM NUMBER GENERATOR CORE"
        <linux-crypto@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
To: Ard Biesheuvel <ard.biesheuvel@linaro.org>
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On Thu, Sep 06, 2018 at 10:11:59AM +0200, Ard Biesheuvel wrote:
>
> That way, we will almost certainly oops on a NULL pointer dereference
> right after, but we at least the stack corruption.

A crash is just as bad as a BUG_ON.

Is this even a real problem? Do we have any users of this construct
that is using it on async algorithms?

Cheers,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt