From: Herbert Xu <herbert@gondor.apana.org.au>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
USB list <linux-usb@vger.kernel.org>,
David Howells <dhowells@redhat.com>,
keyrings@vger.kernel.org, Eric Biggers <ebiggers3@gmail.com>,
linux-crypto@vger.kernel.org,
Stephan Mueller <smueller@chronox.de>
Subject: Re: [PATCH v2] keys/encrypted: Fix two crypto-on-the-stack bugs
Date: Wed, 14 Dec 2016 13:04:04 +0800 [thread overview]
Message-ID: <20161214050404.GC9592@gondor.apana.org.au> (raw)
In-Reply-To: <CALCETrX-YYp5iXPLKOpiT9+3DXYxGTVRXVyPN0oiYpQQC8kH3w@mail.gmail.com>
On Tue, Dec 13, 2016 at 06:53:03PM -0800, Andy Lutomirski wrote:
> On Tue, Dec 13, 2016 at 6:48 PM, Andy Lutomirski <luto@kernel.org> wrote:
> > The driver put a constant buffer of all zeros on the stack and
> > pointed a scatterlist entry at it in two places. This doesn't work
> > with virtual stacks. Use ZERO_PAGE instead.
>
> Wait a second...
>
> > - sg_set_buf(&sg_out[1], pad, sizeof pad);
> > + sg_set_buf(&sg_out[1], empty_zero_page, 16);
>
> My fix here is obviously bogus (I meant to use ZERO_PAGE(0)), but what
> exactly is the code trying to do? The old code makes no sense. It's
> setting the *output* buffer to zeroed padding.
It's decrypting so I presume it just needs to the extra space for
the padding and the result will be thrown away.
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
next prev parent reply other threads:[~2016-12-14 5:05 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-14 2:48 [PATCH v2] keys/encrypted: Fix two crypto-on-the-stack bugs Andy Lutomirski
2016-12-14 2:53 ` Andy Lutomirski
2016-12-14 5:04 ` Herbert Xu [this message]
2016-12-14 8:10 ` Eric Biggers
2016-12-14 8:37 ` David Howells
2016-12-14 16:22 ` Andy Lutomirski
2016-12-14 17:00 ` David Howells
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