Quoting Serge E. Hallyn (serue@xxxxxxxxxx): > Quoting Tetsuo Handa (penguin-kernel@xxxxxxxxxxxxxxxxxxx): > > Hello. > > > > Serge E. Hallyn wrote: > > > CAP_MKNOD will be removed from its capability > > I think it is not enough because the root can rename/unlink device files > > (mv /dev/sda1 /dev/tmp; mv /dev/sda2 /dev/sda1; mv /dev/tmp /dev/sda2). > > Sure but that doesn't bother us :) > > The admin in the container has his own /dev directory and can do what he > likes with the devices he's allowed to have. He just shouldn't have > access to others. If he wants to rename /dev/sda1 to /dev/sda5 that's > his choice. > > > > To use your approach, i guess we would have to use selinux (or tomoyo) > > > to enforce that devices may only be created under /dev? > > Everyone can use this filesystem alone. > > Sure but it is worthless alone. > > No? Oh, no, I'm sorry - I was thinking in terms of my requirements again. But your requirements are to ensure that an application accessing a device at a well-known location get what it expect. So then the main quesiton is still the one I think Al had asked - what keeps a rogue CAP_SYS_MOUNT process from doing mount --bind /dev/hda1 /dev/null ? thanks, -serge > What will keep the container admin from doing 'mknod /root/hda1 b 3 1'? > > > But use with MAC (or whatever access control mechanisms that prevent > > attackers from unmounting/overlaying this filesystem) is recomennded. > > -serge - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
