On 04/30/2013 03:45 AM, Rob Landley wrote: > On 04/29/2013 02:45:45 AM, richard -rw- weinberger wrote: >> On Thu, Mar 21, 2013 at 4:52 PM, Michael Kerrisk (man-pages) >> <mtk.manpa...@gmail.com> wrote: >> > Hi Serge, >> > >> > On Fri, Mar 15, 2013 at 4:38 PM, Serge Hallyn <serge.hal...@ubuntu.com> >> > wrote: >> >> Hi, >> >> >> >> you mention that after creating a new user namespace you at first have >> >> all capabilities in the new ns. You don't explicitly mention (or I >> >> missed it - I did see the mention of securebits) that if you want to >> >> keep those capabilities after doing an exec, you need to first have >> >> something mapped to uid 0 in the userns, and do setuid(0). >> > >> > Good point. I'll add something on that. >> > >> >> You might not want to list manpages from other projects, >> > >> > Actually, not a problem. Many of the pages in my set already do this. >> > >> >> but Eric's >> >> shadow patches introduce some good new manpages as well. Those aren't yet >> >> accepted upstream, but if/when they are then mention at least of >> >> subuid(5), subgid(5), and newuidmap(1) and newgidmap(1) might be good. >> > >> > I'll add those. >> > >> > Cheers, >> > >> > Michael >> >> Can we please also document which capabilities are useless within an >> user namespace? >> E.g. CAP_MKNOD. >> You get this capability but the kernel always checks it against the >> initial userns. > > Is there a device namespace? >
No,and I don't think we need device namespace now. > I vaguely recall OpenVZ implemented moving individual PCI devices into > containers so some large movie company could put one video card in each > container for render farms. There are lots of devices > that aren't _really_ privileged (/dev/zero, /dev/null, /dev/full, /dev/ram) > and more that could be emulated... You can create these devices on host for container, and use device cgroup to limit which container can use these devices. > > (Really this seems like a situation where devtmpfs needs -o newinstance and a > corresponding filtered event netlink feed to pass to udev/mdev. And that > might even have been feasible before Greg decided > that devtmpfs needed to have opinions about uids. Oh well.) > > Rob-- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
