---
id: "bug-1951"
status: "fixed"
status_updated: "2026-10-10"
status_note: ""
component: "apiserver"
severity: "crash"
timestamp: "2026-10-10T08:15:14Z"
last_seen: "2026-10-10T08:15:14Z"
occurrences: 1
files: ["src/frontend/apiserver/backend/auth/config_file.go"]
tags: ["apiserver", "auth", "config", "crash"]
related: []
fix_commits: ["d3ce2982"]
gitea_issue: 382
gitea_synced_status: "fixed"
gitea_synced_hash: "0590e8ff3114"
---

# bug-1951: apiserver crashes on an auth.yaml without a config_file block (nil pointer)

## Description
**Observed:** (source reading, `.kiro/reviews/project-gap-review-2026-10-10.md` (P0); to be confirmed by a failing test before the fix)
`backend/auth/config_file.go:39` reads `cfg.ConfigFile.Users` without checking `cfg.ConfigFile` for nil.

**Expected:** A missing block is a clear configuration error, not a panic.
**Impact:** Crash at startup or login with a minimal auth.yaml.
**Found by:** review: `.kiro/reviews/project-gap-review-2026-10-10.md` (P0)
## Environment
- OS: no /etc/os-release; Docker container; NixOS kernel; kernel Linux 6.18.33 x86_64
- libc: glibc 2.42-47 (interpreter /nix/store/wb6rhpznjfczwlwx23zmdrrw74bayxw4-glibc-2.42-47/lib/ld-linux-x86-64.so.2)
- Toolchain: gcc (GCC) 15.2.0, meson 1.9.1
- Build: asan (xce.build)
- Code: scheduler-framework @ 94472ee3-dirty
- Deployment: any (found by source reading; the failing test that confirms it is named in Verification)

## Reproduction
1. Start the apiserver with an `auth.yaml` that selects config-file auth but has no `config_file:` block.
- Frequency: deterministic (by code reading; confirmed by the RED test of the fix)
- Evidence: the code sites quoted in Description; no logs kept.
## Root cause
`NewConfigFileProvider` (`backend/auth/config_file.go:39`) dereferenced `cfg.ConfigFile` without a nil check.

## Fix
Returns a clear configuration error when the `config_file` block is missing.

## Verification
- Test: `TestNewConfigFileProvider_Errors/missing_config_file_block` (`backend/auth/config_file_test.go`): RED `panic: runtime error: invalid memory address or nil pointer dereference`, GREEN after.
- Suites: `xce-build.sh all asan xce.build --incremental` on the merged branch, 2026-10-10: all C suites Ok 155 / Fail 0, frontend Go unit tests ok, xceadmin tests ok; apiserver `CGO_ENABLED=0 go test ./...` (incl. middleware, router, cmd) ok
- Live: n/a: unit/fixture-level verification only; no live deployment was run (follow-up)

## References
- Fix commit: `d3ce2982` (on `scheduler-framework`; worker-branch original in the merge)
- Review: `.kiro/reviews/project-gap-review-2026-10-10.md`