linux-kernel - Re: [RFC PATCH v2] mm: slub: print kernel addresses in slub debug messages

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: <20190809142617.GO5482@bombadil.infradead.org>
Date:   Fri, 9 Aug 2019 07:26:17 -0700
From:   Matthew Wilcox <willy@...radead.org>
To:     Miles Chen <miles.chen@...iatek.com>
Cc:     Christoph Lameter <cl@...ux.com>,
        Pekka Enberg <penberg@...nel.org>,
        David Rientjes <rientjes@...gle.com>,
        Joonsoo Kim <iamjoonsoo.kim@....com>,
        Andrew Morton <akpm@...ux-foundation.org>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, linux-mediatek@...ts.infradead.org,
        wsd_upstream@...iatek.com, "Tobin C . Harding" <me@...in.cc>,
        Kees Cook <keescook@...omium.org>
Subject: Re: [RFC PATCH v2] mm: slub: print kernel addresses in slub debug
 messages

On Fri, Aug 09, 2019 at 10:11:58PM +0800, Miles Chen wrote:
> On Thu, 2019-08-08 at 19:46 -0700, Matthew Wilcox wrote:
> > On Fri, Aug 09, 2019 at 09:08:37AM +0800, miles.chen@...iatek.com wrote:
> > > INFO: Slab 0x(____ptrval____) objects=25 used=10 fp=0x(____ptrval____)
> > 
> > ... you don't have any randomness on your platform?
> 
> We have randomized base on our platforms.

Look at initialize_ptr_random().  If you have randomness, then you
get a siphash_1u32() of the address.  With no randomness, you get this
___ptrval___ string instead.