linux-kernel - Re: [kernel-hardening] [PATCH 4/6] Protectable Memory

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]

Date:   Mon, 12 Feb 2018 15:27:19 -0800
From:   Kees Cook <keescook@...omium.org>
To:     Igor Stoppa <igor.stoppa@...wei.com>
Cc:     Boris Lukashev <blukashev@...pervictus.com>,
        Christopher Lameter <cl@...ux.com>,
        Matthew Wilcox <willy@...radead.org>,
        Jann Horn <jannh@...gle.com>,
        Jerome Glisse <jglisse@...hat.com>,
        Michal Hocko <mhocko@...nel.org>,
        Laura Abbott <labbott@...hat.com>,
        Christoph Hellwig <hch@...radead.org>,
        linux-security-module <linux-security-module@...r.kernel.org>,
        Linux-MM <linux-mm@...ck.org>,
        kernel list <linux-kernel@...r.kernel.org>,
        Kernel Hardening <kernel-hardening@...ts.openwall.com>
Subject: Re: [kernel-hardening] [PATCH 4/6] Protectable Memory

On Sun, Feb 4, 2018 at 7:05 AM, Igor Stoppa <igor.stoppa@...wei.com> wrote:
> On 04/02/18 00:29, Boris Lukashev wrote:
>> On Sat, Feb 3, 2018 at 3:32 PM, Igor Stoppa <igor.stoppa@...wei.com> wrote:
>
> [...]
>
>>> What you are suggesting, if I have understood it correctly, is that,
>>> when the pool is protected, the addresses already given out, will become
>>> traps that get resolved through a lookup table that is built based on
>>> the content of each allocation.
>>>
>>> That seems to generate a lot of overhead, not to mention the fact that
>>> it might not play very well with the MMU.
>>
>> That is effectively what i'm suggesting - as a form of protection for
>> consumers against direct reads of data which may have been corrupted
>> by some irrelevant means. In the context of pmalloc, it would probably
>> be a separate type of ro+verified pool
> ok, that seems more like an extension though.
>
> ATM I am having problems gaining traction to get even the basic merged :-)
>
> I would consider this as a possibility for future work, unless it is
> said that it's necessary for pmalloc to be accepted ...

I would agree: let's get basic functionality in first. Both
verification and the physmap part can be done separately, IMO.

-Kees

-- 
Kees Cook
Pixel Security