Messages in this thread | | | Subject | Re: [PATCH] netfilter: per netns nf_conntrack_cachep | From | Jon Masters <> | Date | Thu, 04 Feb 2010 08:18:06 -0500 |
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On Thu, 2010-02-04 at 14:04 +0100, Patrick McHardy wrote: > Alexey Dobriyan wrote: > > On Thu, Feb 4, 2010 at 2:30 PM, Patrick McHardy <kaber@trash.net> wrote: > >> Alexey Dobriyan wrote: > >>> On Thu, Feb 4, 2010 at 2:25 PM, Patrick McHardy <kaber@trash.net> wrote: > >>>> Jon Masters wrote: > >>>>> On Wed, 2010-02-03 at 21:09 +0200, Alexey Dobriyan wrote: > >>>>>> On Wed, Feb 03, 2010 at 01:38:09PM -0500, Jon Masters wrote: > >>>>>>> *). Per namespace cacheing allocation (the cachep bits). We know it's > >>>>>>> still possible for weirdness to happen in the SLAB cache here. > >>>>>> Tiny race, needs reproducer. > >>>>> Maybe. I think it's worth fixing anyway. > >>>> Absolutely, I'll also apply Eric's patch with the %p fix for the > >>>> slab name. > >>> This would show kernel pointers in userspace ;-) > >>> So, net->id is required. > >> I don't see the problem. But yes, it would be nicer to have an ID. > > > > This is done (or rather, not done) to not show attackers > > where data structures are. > > That's news to me, my /proc is full of kernel space pointers, > including data.
And anyway, you can guess it in many cases. I don't think there's a huge problem, but you could of course just stash a global atomic somewhere to keep track of how many of these you've made if that's easier for now.
> In any case, we need a fix for this suitable for 2.6.33. If > you don't like using the pointer, please send a patch to add > an id to the network namespaces.
Right. I think the quick solution is fine for 2.6.33. So that makes the hashtable non-resize patch, the crash fix, and the cachep bits. I will try to get involved and help you out with the per-ns hashtable clean rather than just being a whiner :)
Thanks a bunch! Fedora kernels have already been built with this fix, since it will allow us to close a fair number of "KVM goes boom" bugs.
Jon.
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