Re: [PATCH v2 02/10] userns: Add per user namespace sysctls.

From	ebiederm@xmission.com (Eric W. Biederman)
Newsgroups	linux.kernel
Subject	Re: [PATCH v2 02/10] userns: Add per user namespace sysctls.
Date	2016-07-26 03:00 +0200
Message-ID	<rYYT0-3wo-5@gated-at.bofh.it> (permalink)
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David Miller <davem@davemloft.net> writes:

> From: ebiederm@xmission.com (Eric W. Biederman)
> Date: Mon, 25 Jul 2016 19:02:01 -0500
>
>>            Which means this change gets has to wait for next cycle.
>
> Ok.

For clarity I intend to merge these changes through the userns tree,
when the issues are resolved.

I Cc'd netdev as there is a limit on the number of network namespaces in
this set which may be of interest to networking folks.

I expect there will be some follow on about adding sanity checking
limits to other kernel data structures like a maximum number of mounts
in a mount namespace, and perhaps a maximum number of routes in a
network namespace.

User namespaces have enabled unprivileged users access to a lot more
data structures and so to catch programs that go crazy we need a lot
more limits.  I believe some of those limits make sense per namespace.
As it is easy in some cases to say any more than Y number of those
per namespace is excessive.   For example a limit of 1,000,000 ipv4
routes per network namespaces is a sanity check as there are
currently 621,649 ipv4 prefixes advertized in bgp.

But that is something to worry about after the merge window.

Eric

Thread

[PATCH v2 02/10] userns: Add per user namespace sysctls. "Eric W. Biederman" <ebiederm@xmission.com> - 2016-07-21 19:00 +0200
  Re: [PATCH v2 02/10] userns: Add per user namespace sysctls. ebiederm@xmission.com (Eric W. Biederman) - 2016-07-26 02:20 +0200
    Re: [PATCH v2 02/10] userns: Add per user namespace sysctls. David Miller <davem@davemloft.net> - 2016-07-26 02:30 +0200
      Re: [PATCH v2 02/10] userns: Add per user namespace sysctls. ebiederm@xmission.com (Eric W. Biederman) - 2016-07-26 03:00 +0200
        Re: [PATCH v2 02/10] userns: Add per user namespace sysctls. David Miller <davem@davemloft.net> - 2016-07-26 05:00 +0200
          Re: [PATCH v2 02/10] userns: Add per user namespace sysctls. ebiederm@xmission.com (Eric W. Biederman) - 2016-07-26 06:20 +0200

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