Manage /etc/subuid and /etc/subgid#48
Open
r-vdp wants to merge 1 commit into
Open
Conversation
Subordinate id ranges have the same reuse risk as normal user ids: files
created by a user's unprivileged containers are owned by ids in their
range, so reassigning the range to another user grants access to those
files.
We cannot precompute suitable ranges outside of userborn because we need
to take into account existing ranges, and with only 31 bits of usable
id space, assigning a static range to each user can quickly run out of
space (especially with some tools like incus assigning massive ranges by
default).
So we treat sub{u,g}id in the same way as normal {u,g}ids: read the
existing file, allocate non-overlapping ranges for users that need one,
and never remove entries.
Closes nikstur#7
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Subordinate id ranges have the same reuse risk as normal user ids: files
created by a user's unprivileged containers are owned by ids in their
range, so reassigning the range to another user grants access to those
files.
We cannot precompute suitable ranges outside of userborn because we need
to take into account existing ranges, and with only 31 bits of usable id
space, assigning a static range to each user can quickly run out of space
(especially with some tools like incus assigning massive ranges by
default).
So we treat sub{u,g}id in the same way as normal {u,g}ids: read the
existing file, allocate non-overlapping ranges for users that need one,
and never remove entries.
This is one of the missing pieces for making userborn the default
user/group management tool in NixOS, where the perl activation script
currently handles
users.users.<name>.subUidRanges/subGidRangesandautoSubUidGidRange.Closes #7
CC: @nikstur