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

- From: David Miller \<hidden\>
- Date: 2016-07-26 02:58:40 
- List: linux-api
- Page: https://ratatoskr.run/linux-api/2016/07/109792
- Thread: https://ratatoskr.run/netdev/2016/07/109793/t.md

```text
From: <redacted> (Eric W. Biederman)
Date: Mon, 25 Jul 2016 19:44:50 -0500

> 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.

When we give a new namespace to unprivileged users, we honestly should
make the sysctl settings we give to them become "limits".  They can
further constrain the sysctl settings but may not raise them.
```