Re: [PATCH] e1000: enhance frame fragment detection

[Neil Horman <nhorman@tuxdriver.com>]

On Mon, Dec 28, 2009 at 04:42:09PM -0800, Jeff Kirsher wrote:
> On Mon, Dec 28, 2009 at 12:10, Neil Horman <nhorman@tuxdriver.com> wrote:
> > Hey all-
> >        A security discussion was recently given:
> > http://events.ccc.de/congress/2009/Fahrplan//events/3596.en.html
> > And a patch that I submitted awhile back was brought up.  Apparently some of
> > their testing revealed that they were able to force a buffer fragment in e1000
> > in which the trailing fragment was greater than 4 bytes.  As a result the
> > fragment check I introduced failed to detect the fragement and a partial invalid
> > frame was passed up into the network stack.  I've written this patch to correct
> > it.  I'm in the process of testing it now, but it makes good logical sense to
> > me.  Effectively it maintains a per-adapter state variable which detects a
> > non-EOP frame, and discards it and subsequent non-EOP frames leading up to _and_
> > _including_ the next positive-EOP frame (as it is by definition the last
> > fragment).  This should prevent any and all partial frames from entering the
> > network stack from e1000
> >
> > Regards
> > Neil
> >
> >
> >  e1000.h      |    3 ++-
> >  e1000_main.c |   14 ++++++++++++--
> >  2 files changed, 14 insertions(+), 3 deletions(-)
> >
> >
> 
> Thanks Neil.  I have add the patch to my queue of patches.
> 
> -- 
> Cheers,
> Jeff
> 
Thanks jeff, much appreciated
Happy Holidays
Neil