On Wed, 25 Jan 2023 16:28:49 +0100 Alexey Gladkov <legion@xxxxxxxxxx> wrote: > If, after creating a container and mounting procfs, the system > configuration may change and new files may appear in procfs. Files > including writable root or any other users. > > In most cases, it is known in advance which files in procfs the user > needs in the container. It is much easier to control the list of what > you want than to control the list of unwanted files. > > To do this, subset=allowlist is added to control the visibility of > static files in procfs (not process pids). After that, the control file > /proc/allowlist appears in the root of the filesystem. This file > contains a list of files and directories that will be visible in this > vmountpoint. Immediately after mount, this file contains only one > name - the name of the file itself. > > The admin can add names, read this file to get the current state of the > allowlist. The file behaves almost like a regular file. Changes are > applied when the file is closed. "the admin" is a bit vague. Precisely which capabilities are required for this? > To prevent changes to allowlist, admin should remove its name from the > list of allowed files. After this change, the file will disappear.
