linux-kernel - Re: [PATCH] keys/encrypted: Fix two crypto-on-the-stack bugs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CALCETrVbEhxRWFmgrePeLriQU5J6ZZaN15tTAYja1hJwYFrRpg@mail.gmail.com>
Date:   Tue, 13 Dec 2016 09:02:07 -0800
From:   Andy Lutomirski <luto@...capital.net>
To:     David Howells <dhowells@...hat.com>
Cc:     David Laight <David.Laight@...lab.com>,
        Joerg Roedel <joro@...tes.org>,
        David Woodhouse <dwmw2@...radead.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Ingo Molnar <mingo@...nel.org>,
        Andy Lutomirski <luto@...nel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-usb@...r.kernel.org" <linux-usb@...r.kernel.org>,
        "keyrings@...r.kernel.org" <keyrings@...r.kernel.org>,
        Eric Biggers <ebiggers3@...il.com>,
        "linux-crypto@...r.kernel.org" <linux-crypto@...r.kernel.org>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        Stephan Mueller <smueller@...onox.de>
Subject: Re: [PATCH] keys/encrypted: Fix two crypto-on-the-stack bugs

On Tue, Dec 13, 2016 at 8:45 AM, David Howells <dhowells@...hat.com> wrote:
> Andy Lutomirski <luto@...capital.net> wrote:
>
>> After all, rodata is ordinary memory, is backed by struct page, etc.
>
> Is that actually true?  I thought some arches excluded the kernel image from
> the page struct array to make the array consume less memory.

I don't know whether you're right, but that sounds a bit silly to me.
This is a *tiny* amount of memory.

But there's yet another snag.  Alpha doesn't have empty_zero_page --
it only has ZERO_PAGE.  I could do page_address(ZERO_PAGE(0))...

--Andy