Re: [v4l-dvb-maintainer] [GIT PATCHES] V4L/DVB updates

[Mauro Carvalho Chehab <mchehab@infradead.org>]

Em Seg, 2007-04-16 às 10:17 +0200, Markus Rechberger escreveu:
> On 4/16/07, Manu Abraham <abraham.manu@gmail.com> wrote:
> > Michael Krufky wrote:
> > > Mauro,
> > >
> > > I've been out of town for the past few days... I just got home and saw
> > this:
> > >
> > >
> > > Mauro Carvalho Chehab wrote:
> > >>    - Fix 1/3 for bug 7819: fixed frontend hotplug issue
> > >>    - Fix 2/3 for bug 7819: demux and dvr
> > >>    - Fix 3/3 for bug 7819: fixed hotplugging for dvbnet
> > > I don't think that this is 2.6.21 material.  These patches have not yet
> > > received
> > > enough testing to be sent to mainline.
> > >
> > > I have tested them, and they seem to work for my cxusb device, but we have
> > > yet to hear test results from users of usb dvb devices that do not use the
> > > dvb-usb framework.  (ttusb, flexcop-usb, cinergyT2, for example)
> > >
> > > The bug that these patches fix has been around throughout the entire
> > kernel
> > > history of the dvb subsystem.  The bug is not a regression -- it has
> > > always been
> > > there.  In my opinion, it is too late in 2.6.21 development to apply
> > > this change.
> > > Because these fixes are not obvious, I think we should let them get some
> > > more testing, and have them queued for 2.6.22 .
> >
> >
> > I am not arguing about the veracity of the patches, but how things are
> > handled.
> >
> > Agreed to all the mentioned above. There is one more aspect. The
> > mentioned patches, do not have any ACK/SOB from any DVB
> > developer/maintainer for the same.
> >
> > Huge regressions are created this way. One more time the regression
> > creator is caught.
> >
> 
> The patch has been around on the dvb mailinglist ([PATCH][RFC] DVB
> Hotplug Fix, 5. April 2007), Michael looked at it when I told him
> about it again separatly (12. April 2007)
> Between that there was enough time to respond on it or review it.
> 
> Mauro told me at the beginning if noone responds he'll go forward
> somehow because it fixes hotplugging, and after 2 weeks I wouldn't
> expect anyone commenting that thread anymore.
> 
> It would be better to look and respond to that patch first before
> responding about that you don't like how it's handled, Mauro also
> wrote in his announcement that people should look at the recent
> mercurial tree and he'll revert it if something doesn't work by
> accident before submitting it to his git tree... still noone
> complained about the hotplugging patch in there.
Ditto.

It is really bad to have an OOPS that can be generated by simply
removing a device at the usb port. This can open a door for DoS attacks.
IMO, this kind of bug should be fixed as soon as possible. 

If you take a look at the history of this bug, it were reported back on
Jan, 14. Also, Adrian sent several regression reports c/c to
v4l-dvb-mailing list (so copying all V4L/DVB maintainers, including you,
me, Markus and the others), warning about the bug, and pointing that a
patch from Markus were already available.

I also explicitly warned at DVB ML that I were about to send this patch,
together with other fixes, asking the community for more tests. After
that, I received two positive answers on my mailbox from people that
tested and noticed that this really fixed the issue.

I don't think that 3 months is a short period of time for us to work on
a solution for the bug and have it done to be included on Kernel.

Cheers,
Mauro