Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Thu, 24 Feb 2011 15:22:32 -0500 (EST)
From: Josh Bressers <bressers@...hat.com>
To: Jon Oberheide <jon@...rheide.org>
Cc: Timo Warns <warns@...-sense.de>, oss-security@...ts.openwall.com,
        coley <coley@...re.org>
Subject: Re: CVE request: kernel: fs/partitions: Kernel heap
 overflow via corrupted LDM partition tables


----- Original Message -----
> On Thu, 2011-02-24 at 09:25 +0800, Eugene Teo wrote:
> > On 02/24/2011 03:59 AM, Josh Bressers wrote:
> > > ----- Original Message -----
> > >>
> > >> The kernel automatically evaluates partition tables of storage
> > >> devices.  The code for evaluating LDM partitions (in
> > >> fs/partitions/ldm.c) contains a bug that allows to overflow the
> > >> kernel heap. It may be possible to escalate privileges by exploiting
> > >> this bug.
> > >>
> > >> (This bug is distinct from the LDM bug reported by Eugene Teo on
> > >> 2011-02-23.)
> > >>
> > >> This should affect both, 2.4 and 2.6 kernel. As a prerequisite,
> > >> CONFIG_LDM_PARTITION needs to be set.
> > >>
> > >
> > > Can you point to a commit message or something else that is public?
> > > It's not clear how this differs from Eugene's request.
> >
> > As far as I can tell, it's not public yet. Timo will follow-up once his
> > patch is accepted.
> 
> The advisory Timo posted mentioned ldm_frag_add() so it's public for all
> practical purposes at this point:
> 
> static bool ldm_frag_add (const u8 *data, int size, struct list_head
> *frags)
> {
> ...
> f = kmalloc (sizeof (*f) + size*num, GFP_KERNEL);
> if (!f) {
> ldm_crit ("Out of memory.");
> return false;
> }
> ...
> memcpy (f->data+rec*(size-VBLK_SIZE_HEAD)+VBLK_SIZE_HEAD, data,
> size);
> return true;
> }
> 

I would still like something along the lines of a proposed patch. I believe
you folks (as you're much brighter than me), but I still don't quite grasp
the difference. I suspect there is enough public information for MITRE to
public a CVE though, so please use CVE-2011-1017.

Thanks.

-- 
    JB

Powered by blists - more mailing lists

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.