Re: [PATCH -mm 5/7] add user namespace

[Dave Hansen <haveblue@us.ibm.com>]

On Thu, 2006-07-13 at 13:02 -0600, Eric W. Biederman wrote:
> All comparisons of a user equality need to be of the tuple (user namespace, user id).
> Any comparison that does not do that is an optimization.
...
> So my impression was that Cedric's patchset was overoptimized because
> it did not change most of the uid comparisons, to (user namespace, user id).

I might just be tempted to call them bugs so people understand what I'm
talking about ;)

> Because you can have access to files created in another user namespace it
> is very unlikely that optimization will apply very frequently.  The easy scenario
> to get access to a file descriptor from another context is to consider unix
> domain sockets.

OK, so you're saying that the lack of checks will cause problems rarely,
and that passing a fd across a unix domain sockets is one of the times
when you _could_ encounter this problem?

-- Dave

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