Re: [patch] to add device+inode check to ipt_owner.c - HACKED UP

From: Luke Kenneth Casson Leighton
Date: Fri Sep 10 2004 - 04:52:35 EST


On Fri, Sep 10, 2004 at 08:49:28AM +0100, Gianni Tedesco wrote:
> On Wed, 2004-09-08 at 11:39 +0100, Luke Kenneth Casson Leighton wrote:
> > ... did i sent a patch?
> >
> > did i send a patch?? i don't _think_ so *lol* :)
>
> heh :)
>
> IMO the number of constraints involed here make using this patch fairly
> involved (for something security related at least) in that, as you said,
> you have to:
>
> - be careful to use ACCEPT rules only
> - be careful that you do:
> 1. remove fw rules
> 2. upgrade software
> 3. replace rules

i've since replaced the code with use of d_path() which stephen
smalley kindly pointed out, negating the need for doing a
commit-replace-thing.

> plus the fastpath code looks very hairy with at least 3 locks taken and
> O(num_tasks * max_fds) unpreemptable in softirq...

*shrug*. that's the way ipt_owner works...

> There has to be a simpler approach, perhaps passing in a path, looking
> up the dentry in current namespace and setting an unused flag in
> d_vfs_flags? That way you could just match on skb->sk->sk_socket->file-
> >f_dentry.

ooo...

> I don't know enough about VFS to know if that's really possible. I mean
> would you need vfsmnt too to make it accurate across namespaces?


well you need vfsmnt in order to trackdown the full path name.

l.

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