---
id: "bug-1868"
status: "fixed"
status_updated: "2026-09-26"
status_note: "7864a3da: xcecd_create_job_output() unlinks then creates with O_EXCL|O_NOFOLLOW|O_CLOEXEC."
component: "worker"
severity: "security"
timestamp: "2026-09-26T07:40:17Z"
last_seen: "2026-09-26T07:40:17Z"
occurrences: 1
files: ["src/worker/src/uv_proc.c"]
tags: ["security", "worker", "symlink", "tmp", "uv_proc"]
related: ["bug-1508"]
fix_commits: ["7864a3da"]
legacy: true
gitea_issue: 288
gitea_synced_status: "fixed"
gitea_synced_hash: "a6d6a8485b1c"
---

# bug-1868: uv_proc_exec (worker/src/uv_proc.c) creates each task's output file /tmp/job_<jobid>_task<N>.out…

## Description
uv_proc_exec (worker/src/uv_proc.c) creates each task's output file /tmp/job_<jobid>_task<N>.out as root with O_WRONLY|O_CREAT|O_TRUNC and no O_NOFOLLOW/O_EXCL: a local user who pre-plants a symlink at a predictable future job's output name makes the root worker truncate and write job output into the symlink target

## Environment
_Not recorded (migrated from buglog.json)._

## Reproduction
_Not recorded (migrated from buglog.json)._

## Root cause
Predictable name in world-writable /tmp opened by root following symlinks. Only mitigated by the host's fs.protected_symlinks / fs.protected_regular sysctls, not by the code. Sibling of bug-1508 (read side, fixed in 7723a4f4).

## Fix
_Not recorded (migrated from buglog.json)._

## Verification
_Not recorded (migrated from buglog.json)._

## References
- Related: bug-1508
- Gitea: #288