Re: [PATCH 3.12 28/88] netfilter: x_tables: validate targets of jumps

From: Florian Westphal
Date: Mon Jul 25 2016 - 03:03:38 EST


Michal Kubecek <mkubecek@xxxxxxx> wrote:
> On Thu, Jul 21, 2016 at 09:00:33PM +0200, Jiri Slaby wrote:
> > On 07/21/2016, 08:56 PM, Greg KH wrote:
> > > On Thu, Jul 21, 2016 at 08:36:18AM +0200, Jiri Slaby wrote:
> > >> On 07/14/2016, 10:15 AM, Jiri Slaby wrote:
> > >>> From: Florian Westphal <fw@xxxxxxxxx>
> > >>>
> > >>> 3.12-stable review patch. If anyone has any objections, please let me know.
> > >>>
> > >>> ===============
> > >>>
> > >>> commit 36472341017529e2b12573093cc0f68719300997 upstream.
> > >>
> > >> I am now dropping this one. 3.12.62 will be released without that patch.
> > >> After the performance issue is resolved, it will be requeued.
> > >
> > > Personally, I think the bug fixes were more important than the
> > > performance issues at this point in time, but it's your call to make :)
> >
> > Ok, but to quote [1]:
> > iptables-restore will take forever (gave up after 10 minutes)
> >
> > I would say it proved itself not to be a performance issue, but rather a
> > functional issue :). Both Pablo and Florian suggested to postpone the patch.
>
> Even worse: because of a shared lock which is held for all this time,
> this allows (on kernel >= 3.8) an unprivileged user to block similar
> operation in all network namespaces including init_net.

What lock are you talking about?

The table lock is aquired after the sanity/translation pass.