Wireshark-dev: Re: [Wireshark-dev] [Wireshark-commits] rev 49644: /trunk/epan/ /trunk/epan/: pr
From: Jakub Zawadzki <[email protected]>
Date: Fri, 31 May 2013 18:59:34 +0200
Hi,

On Thu, May 30, 2013 at 10:23:05PM -0400, Evan Huus wrote:
> On Thu, May 30, 2013 at 10:15 PM, Evan Huus <[email protected]> wrote:
> > On Thu, May 30, 2013 at 9:46 PM,  <[email protected]> wrote:
> >> http://anonsvn.wireshark.org/viewvc/viewvc.cgi?view=rev&revision=49644
> >>
> >> User: morriss
> >> Date: 2013/05/30 06:46 PM
> >>
> >> Log:
> >>  (Finally!) check in part of Didier's patch to fix
> >>  https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=3290
> >>  (TRY_TO_FAKE_THIS_ITEM disables bounds errors):
> >>
> >>  Before calling TRY_TO_FAKE_THIS_ITEM() check if the length given (or, in
> >>  the case of FT_UINT_{STRING,BYTES}, the length we retrieve from the TVB)
> >>  exceeds what's left in the TVB.
> >>
> >>  Do this only for proto_tree_add_item() for now (it's the most commonly used
> >>  and thus the biggest trouble maker in this area).
> >>
> >>  Similar changes for other APIs will come later (if nothing blows up).  Despite
> >>  the fuzz failures this bug has caused I'm not sure about back-porting it...
> >>
> >> Directory: /trunk/epan/
> >>   Changes    Path          Action
> >>   +28 -3     proto.c       Modified
> >
> > Thank you for this!
> >
> > If we get through a round or two of fuzz-testing without any failures
> > I would really like to see this backported to every stable branch
> > (even 1.6). It closes an entire class of security vulnerabilities, and
> > while it is a fairly non-trivial behavioural change in a hot code
> > path, it is relatively short and clearly not doing anything too odd.
> >
> > Fingers crossed for no unexpected side-effects...
> > Evan
> 
> P.S. I don't know when we're expecting 1.10 final but I think delaying
> it (if necessary) in order to include this fix is fully justified.

Has anyone performed some benchmarks before/after this patch? :)

Cheers,
Jakub.