Commit Graph

2 Commits

Author SHA1 Message Date
ignacionelson f1b35cc9f6 Stop a deleted file locking a scoped staff member out of a group for good
#1701 closed a real hole: group membership decides what a client reaches,
and through File::scopeVisibleToClient it decides what the staff member
holding that client reaches, so `edit_groups` alone was never a boundary.
The predicate it added asks whether everything shared with a group is
already inside the actor's library.

It asked by counting: pluck the group's assignment rows, count how many
of those ids the library query returns, and require the two to match. An
assignment row outlives the thing it points at — nothing clears them when
a file or folder is deleted — while files() and folders() exclude trashed
rows by construction. So one deleted file left a count that could never
balance again, and the group closed permanently: the scoped staff member
could no longer add their own client to it, or remove anybody from it,
with a 403 and nothing to explain it. Every group accumulates dead
assignments over time, so groups would have gone quiet one at a time.

Asked the other way round — is there anything live, shared with this
group, that is outside my library — the dead rows drop out by
construction, because the query starts from File/Folder rather than from
the assignment. That is also the truer question: a deleted file is not
reach, since nobody can reach it.

Three tests. A group stays usable after a file shared with it is deleted,
including removing a member; the same for a deleted folder assignment;
and the half that must not soften — a live file still out of reach is
still refused, deleted siblings or not.
2026-08-26 15:21:30 -03:00
denkfabrik-li 8a6543073b Group membership is a library boundary, not just a list
The four routes that edit a group's membership -- add and remove, web
and API -- contain no authorization call of any kind. `can:edit_groups`
in front of them is the whole of it, and a permission is not a boundary.

The authorization sweep looked at these and let them stand, on the
grounds that groups are installation-wide by design: GroupsController
::index lists every group unfiltered, so list and single-object access
agree, and there is no listing/direct-access mismatch to fix. That is
true, and it is the answer to the question of who may *see* a group.
This is a different question: what a write to one *does*.

Joining a group hands the new member everything shared with it. When
that member is one of a client-scoped staff member's own clients,
File::scopeVisibleToClient hands the same content straight back to them
-- that scope is what StaffLibraryScope::files() is built out of. So the
one write turns a file they get a 403 on into a file in their library,
and the download that follows is a 200. ResolvesShareTargets draws that
line on the sharing path through canAssignGroup(); nobody drew it on the
membership path, and canAssignGroup() is *derived from membership*, so
whoever may edit the list also decides what the list entitles them to.

StaffLibraryScope::allowsGroupMembership answers it directly instead of
through the derived predicate, which is the wrong tool here twice over.
Membership asks about reach, so it checks reach: the client must be one
this staff member holds, and the group must not already reach past their
library -- no file assigned to it, and no folder shared with it, outside
StaffLibraryScope. A group nothing has been shared with passes trivially,
which matters, because canAssignGroup() would have said no to a group
that has no members yet and left a scoped staff member unable to put the
first client into one they had just created.

The same write has a second door. MembershipRequestsController::approve
joins a client to a group with identical consequences, under
`approve_groups_memberships_requests`, and deny() decides about somebody
else's client and emails them about it. Both go through the same
boundary, answering 404 to match the guard already above approve().

The queue and its sidebar badge are narrowed to the clients the viewer
holds, through one scope on the model that both read -- the rule the
comment badge in HandleInertiaRequests already states two branches down
("a client-scoped staff member is not shown a number they cannot act
on"), and the reason VisibleCommentScope owns its own pendingTotal()
rather than leaving the middleware to count for itself. Each row carries
the client's name and email, so an unnarrowed queue was also handing
those over for clients outside the roster. Unscoped staff still see every
pending request.

That narrowing is on the client, not on the group: whether a group is
reachable depends on what is shared with it, which is not a question to
ask row by row in a listing. A scoped viewer may therefore still be
shown a request they would be refused on -- one of their own clients
asking to join a group out of their reach. The names were the part that
leaked.

Unscoped staff are unaffected throughout -- both halves of the predicate
are true for them by construction. No seeded role reaches this: Client
Manager is the only client-scoped role that ships, and it holds no group
permissions, so a custom role is needed to get here at all.

The published API document gains a 403 on both member routes.
Regenerated with php artisan scramble:export; Scramble reads abort_unless
out of the method body but not out of a private helper, which is why the
guard is written out at each of the four call sites rather than shared.
2026-08-26 08:49:48 +02:00