System info and instances fail with 500 when pg_stat_activity hides backend_start (Temporal.Instant.from on null)

[dfridenhour]

Summary

GET /_api/system/info returns 500, and the admin dashboard shows zero counts, when the database role Wiki.js runs as can't see full rows in pg_stat_activity. The instances list uses the same code, so it fails too.

Cause

getInstances() in backend/api/system.ts reads backend_start and state_change from pg_stat_activity and passes them straight to Temporal.Instant.from(). Postgres returns NULL for those columns on any session whose role the querying role isn't a member of, unless it has pg_read_all_stats. Temporal.Instant.from(null) throws, so the whole route fails.

This happens even for Wiki.js's own connections when the login role differs from the role Wiki.js acts as. A common least-privilege setup does exactly that: a login with ALTER ROLE ... SET role = app_role, where app_role owns the schema. The session's user is the login, the current user is app_role, and app_role isn't a member of the login. Postgres treats the session as another user's and leaves those columns NULL. Granting pg_read_all_stats would expose every session on the cluster, so it isn't a good workaround.

Reproduce

1. Create a login role wiki_login and a NOLOGIN role wiki_app that owns the database. Grant wiki_app to wiki_login WITH INHERIT FALSE, SET TRUE, and run ALTER ROLE wiki_login SET role = 'wiki_app'.
2. Run Wiki.js 3.0.2 as wiki_login.
3. Open the admin dashboard. /_api/system/info returns {"ok":false,"statusCode":500,"message":"Internal Server error"}.

With sqlLog on, the last query before the error is:

SELECT usename, client_addr, application_name, backend_start, state_change FROM pg_stat_activity WHERE datname = $1 AND application_name LIKE 'Wiki.js%'

Suggested fix

Skip, or count without timestamps, rows where backend_start or state_change is NULL, for example:

inst.backend_start = inst.backend_start ? Temporal.Instant.from(inst.backend_start).toString({ smallestUnit: 'millisecond' }) : null
inst.state_change = inst.state_change ? Temporal.Instant.from(inst.state_change).toString({ smallestUnit: 'millisecond' }) : null

Alternatively, compare usename with session_user in the query, so only the instance's own sessions are read, and handle NULL either way.

Environment

• Wiki.js 3.0.2, the official container image
• PostgreSQL 18.6, managed, without superuser
• Pages, sign-in, editing and storage are unaffected. Only the dashboard counts and the instances list fail.

[NGPixel]

Fixed via fe75227. Will land in next release.