fix: chmod mkdtempSync dirs and add file-permissions-checker CI by lpcox · Pull Request #6311 · github/gh-aw-firewall

lpcox · 2026-07-16T19:41:45Z

Problem

[ERROR] Fatal error: Error: EACCES: permission denied, open '/tmp/awf-chroot-v7CTUn/hosts'

PR #6285 (merged today) added a diagnostic + fallback for the initial EACCES, but the fallback itself uses the same broken mkdtempSync pattern — creating a new temp dir that also gets mode=600 from the runner's restrictive umask (0177).

Root Cause

On Ubuntu 24.04 runners (ubuntu24/20260714.240), the process umask is 0177. Node.js mkdtempSync applies the umask to the default 0700 mode, resulting in directories with 0600 (missing the execute bit). Without the execute bit, no files can be created inside the directory → EACCES.

Fix

1. `src/services/agent-volumes/hosts-file.ts`

Added fs.chmodSync(dir, 0o700) after both mkdtempSync calls (primary path and fallback). chmodSync is not affected by umask — it sets the exact mode.

2. New CI: `.github/workflows/file-permissions-checker.yml`

Comprehensive checker that prevents this entire class of bug from recurring:

Static analysis (errors = CI fails):

mkdtempSync without a following chmodSync

Static analysis (warnings = informational):

mkdirSync with mode but no chmodSync backup
Cleanup file operations without try/catch (identifies 19 instances)
execa.sync('chmod') without error handling

Runtime tests (8 tests, run under simulated umask 0177):

mkdtemp + chmod works
mkdtemp WITHOUT chmod fails (validates threat model)
mkdirSync + chmod works
Exact hosts-file.ts pattern end-to-end
Nested 3-level directory creation
Artifact preservation (rename + readdir + rm)
Cross-UID cleanup (chmod-repair-retry pattern)
Chroot-home mountpoint loop

Runs on both ubuntu-latest and ubuntu-24.04 matrices and under forced restrictive umask.

Testing

All 9 existing hosts-file tests pass
New permissions checker passes locally (8/8 runtime tests, 0 static errors)
23 warnings identified for future hardening (non-blocking)

The EACCES fallback in hosts-file.ts (PR #6285) still crashed because the fallback path also used mkdtempSync without overriding the restrictive umask (0177) that some Ubuntu 24.04 runners apply. Both the primary and fallback mkdtempSync now get an explicit chmodSync(dir, 0o700). Additionally, adds a comprehensive file-permissions-checker CI workflow that catches this class of bug via: - Static analysis: detects mkdtempSync without chmod, mkdirSync mode without chmod, unguarded cleanup file ops, execa chmod without error handling - Runtime tests: validates all critical directory creation patterns under a simulated restrictive umask (0177) Closes github/gh-aw#46062 Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 8bef4805-c013-4d25-908f-125577735990

The cross-uid-cleanup-resilience test creates a directory then writes a file into it. Under umask 0177 (as set by the CI step), mkdirSync creates the dir with mode 0600 (no execute bit), so the writeFileSync fails before we even get to restrict the dir to 0555. Fix: chmod the dir to 0755 immediately after creation, then restrict it after writing the test file. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 8bef4805-c013-4d25-908f-125577735990

github-actions · 2026-07-16T19:44:07Z

✅ Coverage Check Passed

Overall Coverage

Metric	Base	PR	Delta
Lines	99.01%	99.04%	📈 +0.03%
Statements	98.95%	98.98%	📈 +0.03%
Functions	99.35%	99.35%	➡️ +0.00%
Branches	95.15%	95.15%	➡️ +0.00%

📁 Per-file Coverage Changes (1 files)

File	Lines (Before → After)	Statements (Before → After)
`src/log-directory-setup.ts`	96.2% → 100.0% (+3.78%)	96.3% → 100.0% (+3.71%)

Coverage comparison generated by scripts/ci/compare-coverage.ts

Copilot

Pull request overview

Fixes restrictive-umask failures when creating chroot hosts files and adds CI permission checks.

Changes:

Explicitly applies 0700 permissions to primary and fallback temporary directories.
Adds static permission analysis and runtime checks.
Adds a dedicated CI workflow.

Show a summary per file

File	Description
`src/services/agent-volumes/hosts-file.ts`	Hardens temporary directory permissions.
`scripts/ci/check-file-permissions.ts`	Adds static and runtime permission checks.
`.github/workflows/file-permissions-checker.yml`	Runs the new checker in CI.

Review details

Tip

Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

Files reviewed: 3/3 changed files
Comments generated: 5
Review effort level: Medium

+jobs:
+  file-permissions-check:
+    name: Check File Permission Patterns
+    runs-on: ubuntu-latest


+      // Extract the variable name assigned from mkdtempSync
+      const assignMatch = line.match(/(?:const|let|var)\s+(\w+)\s*=\s*(?:fs\.)?mkdtempSync/);
+      if (!assignMatch) continue;


+      fs.unlinkSync(testFile);
+      return {
+        name: 'mkdtempSync-without-chmod-fails (umask enforcement)',
+        passed: true,


+            // Create a chroot subdir like hosts-file.ts does
+            const chrootDir = fs.mkdtempSync(path.join(workDir, 'chroot-'));
+            fs.chmodSync(chrootDir, 0o700);


+    // Create a subdirectory and remove write permission (simulates root-owned dir)
+    const restrictedDir = path.join(testDir, 'restricted');
+    fs.mkdirSync(restrictedDir);
+    fs.writeFileSync(path.join(restrictedDir, 'file.txt'), 'data');
+    fs.chmodSync(restrictedDir, 0o555); // read+execute only


- Wire matrix.os to runs-on so ubuntu-24.04 actually runs on that image - Handle multiline mkdtempSync assignments in static analysis (look back up to 3 lines for split const/let declarations) - Negative test now fails on Linux if EACCES can't be reproduced (validates the threat model is testable on the CI environment) - Integration test imports actual built generateHostsFileMount function instead of reimplementing the pattern inline - Rename cross-uid test to chmod-repair-retry-pattern (honest about what it tests: the local chmod+retry logic, not Docker-based repair) - Add explicit mode to all writeFileSync calls (fixes CodeQL js/insecure-temporary-file alert) Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 8bef4805-c013-4d25-908f-125577735990

github-actions · 2026-07-16T19:58:49Z

✅ Copilot review passed with no inline comments.

@lpcox Add the ready-for-aw label to this PR to trigger agentic CI smoke tests.

github-actions · 2026-07-16T20:18:09Z

✅ Smoke Copilot BYOK completed. Copilot BYOK mode operational. 🔓

github-actions · 2026-07-16T20:18:10Z

✅ Smoke Gemini completed. All facets verified. 💎

github-actions · 2026-07-16T20:18:10Z

✅ Build Test Suite completed successfully!

github-actions · 2026-07-16T20:18:11Z

📰 VERDICT: Smoke Docker Sbx has concluded. All systems operational. This is a developing story. 🎤

github-actions · 2026-07-16T20:18:12Z

❌ Smoke Copilot BYOK AOAI (api-key) reports failed. AOAI BYOK (api-key) mode investigation needed...

github-actions · 2026-07-16T20:18:13Z

Chroot tests passed! Smoke Chroot - All security and functionality tests succeeded.

github-actions · 2026-07-16T20:18:13Z

🔑 Smoke Copilot PAT PAT auth validated. All systems operational. ✅

github-actions · 2026-07-16T20:18:14Z

✅ Contribution Check completed successfully!

PR #6311 follows the applicable CONTRIBUTING.md guidelines: clear description with related references, appropriate file organization, tests/runtime coverage for the permission fix, and no documentation update is required for this internal bug fix.

github-actions · 2026-07-16T20:18:14Z

✅ Smoke Claude passed

github-actions · 2026-07-16T20:18:15Z

📰 VERDICT: Smoke Copilot has concluded. All systems operational. This is a developing story. 🎤

github-actions · 2026-07-16T20:18:17Z

❌ Smoke Copilot BYOK AOAI (Entra) reports failed. AOAI BYOK (Entra) mode investigation needed...

github-actions · 2026-07-16T20:18:31Z

🔌 Smoke Services — All services reachable! ✅

github-actions · 2026-07-16T20:18:34Z

✨ The prophecy is fulfilled... Smoke Codex has completed its mystical journey. The stars align. 🌟

github-actions · 2026-07-16T20:18:34Z

🚀 Security Guard has started processing this pull request

github-actions · 2026-07-16T20:18:39Z

📡 Smoke OTel Tracing completed. All tracing scenarios validated. ✅

github-actions · 2026-07-16T20:21:37Z

Smoke Test: Claude Engine Validation

Check	Result
API Status	✅ PASS
GH Check	✅ PASS
File Status	✅ PASS

Overall Result: PASS

Warning

Firewall blocked 1 domain

The following domain was blocked by the firewall during workflow execution:

awmgmcpg

To allow these domains, add them to the network.allowed list in your workflow frontmatter:

network:
  allowed:
    - defaults
    - "awmgmcpg"

See Network Configuration for more information.

Generated by Smoke Claude for #6311 · 56.1 AIC · ⊞ 3.3K · ◷
_{Add label ready-for-aw to run again}

github-actions · 2026-07-16T20:21:37Z

Smoke Test: PAT Auth Validation

Test	Result
GitHub MCP connectivity	✅
GitHub.com HTTP	✅ (200)
File write/read	⚠️ (template vars unexpanded in runner)

Overall: PASS
Auth mode: PAT (COPILOT_GITHUB_TOKEN) | @lpcox

Warning

Firewall blocked 1 domain

The following domain was blocked by the firewall during workflow execution:

awmgmcpg

To allow these domains, add them to the network.allowed list in your workflow frontmatter:

network:
  allowed:
    - defaults
    - "awmgmcpg"

See Network Configuration for more information.

🔑 PAT report filed by Smoke Copilot PAT
_{Add label ready-for-aw to run again}

github-actions · 2026-07-16T20:21:46Z

🔬 Smoke Test Results

Test	Result
GitHub MCP Connectivity	✅
GitHub.com HTTP	⚠️ pre-step vars unexpanded
File Write/Read	⚠️ pre-step vars unexpanded

Overall: PASS (engine reachable; template vars not resolved in this run)

@lpcox — smoke test complete.

Warning

Firewall blocked 1 domain

The following domain was blocked by the firewall during workflow execution:

awmgmcpg

To allow these domains, add them to the network.allowed list in your workflow frontmatter:

network:
  allowed:
    - defaults
    - "awmgmcpg"

See Network Configuration for more information.

📰 BREAKING: Report filed by Smoke Copilot
_{Add label ready-for-aw to run again}

github-actions · 2026-07-16T20:22:11Z

Smoke Test: Copilot BYOK (Direct) Mode

Test	Result
GitHub MCP (list PRs)	✅
GitHub.com connectivity	✅
File write/read	✅
BYOK inference (agent → api-proxy → api.githubcopilot.com)	✅

Running in direct BYOK mode (COPILOT_PROVIDER_API_KEY) via api-proxy → api.githubcopilot.com

Overall: PASS

@lpcox

Warning

Firewall blocked 1 domain

The following domain was blocked by the firewall during workflow execution:

awmgmcpg

To allow these domains, add them to the network.allowed list in your workflow frontmatter:

network:
  allowed:
    - defaults
    - "awmgmcpg"

See Network Configuration for more information.

🔑 BYOK report filed by Smoke Copilot BYOK
_{Add label ready-for-aw to run again}

github-actions · 2026-07-16T20:22:27Z

Gemini Smoke Test Results

PR Reviews: ❌ (Access Denied by Secrecy Policy)
Connectivity: ❌ (No Internet Access)
File Writing: ✅
Bash Tool: ✅

Overall Status: FAIL

Warning

Firewall blocked 1 domain

The following domain was blocked by the firewall during workflow execution:

localhost

To allow these domains, add them to the network.allowed list in your workflow frontmatter:

network:
  allowed:
    - defaults
    - "localhost"

See Network Configuration for more information.

💎 Faceted by Smoke Gemini
_{Add label ready-for-aw to run again}

github-actions · 2026-07-16T20:22:28Z

Smoke Test: GitHub Actions Services Connectivity

Redis PING: ❌ (host.docker.internal DNS fails; 172.17.0.1 unreachable)
PostgreSQL pg_isready: ❌ (no response)
PostgreSQL SELECT 1: ❌ (cannot connect)

Overall: FAIL — service containers are not reachable from this runner environment.

Warning

Firewall blocked 1 domain

The following domain was blocked by the firewall during workflow execution:

awmgmcpg

To allow these domains, add them to the network.allowed list in your workflow frontmatter:

network:
  allowed:
    - defaults
    - "awmgmcpg"

See Network Configuration for more information.

🔌 Service connectivity validated by Smoke Services
_{Add label ready-for-aw to run again}

github-actions · 2026-07-16T20:23:21Z

🔍 Smoke Test: API Proxy OpenTelemetry Tracing

Scenario	Result	Details
Module Loading	✅ Pass	`otel.js` loads successfully; exports: `startRequestSpan`, `setTokenAttributes`, `setBudgetAttributes`, `endSpan`, `endSpanError`, `shutdown`, `isEnabled` + internal helpers
Test Suite	✅ Pass	39/39 tests passed in `otel.test.js` — covers ProxyAwareOtlpExporter, FileSpanExporter, FanOutSpanExporter, shutdown, span lifecycle
Env Var Forwarding	✅ Pass	`src/services/api-proxy-env-config.ts` forwards `GH_AW_OTLP_ENDPOINTS`, `OTEL_EXPORTER_OTLP_ENDPOINT`, `OTEL_EXPORTER_OTLP_HEADERS`, `GITHUB_AW_OTEL_TRACE_ID`, `GITHUB_AW_OTEL_PARENT_SPAN_ID`, `OTEL_SERVICE_NAME` to api-proxy container
Token Tracker Integration	✅ Pass	`onUsage` callback exists at line 343 of `token-tracker-http.js` — OTEL hook point is wired
OTEL Diagnostics	⚠️ N/A	DinD not available in sandbox; file-based fallback (`/var/log/api-proxy/otel.jsonl`) is the graceful-degradation path when no OTLP endpoint is configured

Summary: All 4 directly testable scenarios pass. Scenario 5 (live span export) requires a running container and is expected-pending in this sandbox. No unexpected failures.

Warning

Firewall blocked 1 domain

The following domain was blocked by the firewall during workflow execution:

awmgmcpg

To allow these domains, add them to the network.allowed list in your workflow frontmatter:

network:
  allowed:
    - defaults
    - "awmgmcpg"

See Network Configuration for more information.

📡 OTel tracing validated by Smoke OTel Tracing
_{Add label ready-for-aw to run again}

github-actions · 2026-07-16T20:24:02Z

🔍 Smoke Test: Docker Sbx Validation

Test	Result
GitHub MCP	✅ Connected (filtered by secrecy policy — expected)
GitHub.com HTTP	⚠️ N/A — template vars not substituted
File Write/Read	⚠️ N/A — template vars not substituted

Overall: PARTIAL — MCP connectivity confirmed; pre-computed step outputs were not injected (template substitution failed in workflow).

PR #6311 author: @lpcox

📰 BREAKING: Report filed by Smoke Docker Sbx
_{Add label ready-for-aw to run again}

github-actions · 2026-07-16T20:24:16Z

Chroot Version Comparison Results

Runtime	Host Version	Chroot Version	Match?
Python	Python 3.12.13	Python 3.12.3	❌ NO
Node.js	v24.18.0	v22.23.1	❌ NO
Go	go1.22.12	go1.22.12	✅ YES

ALL_TESTS_PASSED: false — Python and Node.js versions differ between host and chroot environments.

Warning

Firewall blocked 1 domain

The following domain was blocked by the firewall during workflow execution:

awmgmcpg

To allow these domains, add them to the network.allowed list in your workflow frontmatter:

network:
  allowed:
    - defaults
    - "awmgmcpg"

See Network Configuration for more information.

Tested by Smoke Chroot
_{Add label ready-for-aw to run again}

github-actions · 2026-07-16T20:24:22Z

🏗️ Build Test Suite Results

Ecosystem	Project	Build/Install	Tests	Status
Bun	elysia	✅	1/1 passed	✅ PASS
Bun	hono	✅	1/1 passed	✅ PASS
C++	fmt	✅	N/A	✅ PASS
C++	json	✅	N/A	✅ PASS
Deno	oak	N/A	1/1 passed	✅ PASS
Deno	std	N/A	1/1 passed	✅ PASS
.NET	hello-world	✅	N/A	✅ PASS
.NET	json-parse	✅	N/A	✅ PASS
Go	color	✅	1/1 passed	✅ PASS
Go	env	✅	1/1 passed	✅ PASS
Go	uuid	✅	1/1 passed	✅ PASS
Java	gson	✅	1/1 passed	✅ PASS
Java	caffeine	✅	1/1 passed	✅ PASS
Node.js	clsx	✅	passed	✅ PASS
Node.js	execa	✅	passed	✅ PASS
Node.js	p-limit	✅	passed	✅ PASS
Rust	fd	✅	1/1 passed	✅ PASS
Rust	zoxide	✅	1/1 passed	✅ PASS

Overall: 8/8 ecosystems passed — ✅ PASS

Warning

Firewall blocked 1 domain

The following domain was blocked by the firewall during workflow execution:

awmgmcpg

To allow these domains, add them to the network.allowed list in your workflow frontmatter:

network:
  allowed:
    - defaults
    - "awmgmcpg"

See Network Configuration for more information.

Generated by Build Test Suite for #6311 · 42.2 AIC · ⊞ 6.9K · ◷
_{Add label ready-for-aw to run again}

github-actions · 2026-07-16T20:24:59Z

Smoke Test

Deduplicate OIDC test env isolation across API proxy config suites ✅
Refactor duplicated hosts-file mount test harness setup ✅
GitHub page title check ❌
File write/cat ✅
Discussion comment ✅
Build ❌ (npm ci registry 403)
Overall: FAIL

Warning

Firewall blocked 2 domains

The following domains were blocked by the firewall during workflow execution:

awmgmcpg
registry.npmjs.org

To allow these domains, add them to the network.allowed list in your workflow frontmatter:

network:
  allowed:
    - defaults
    - "awmgmcpg"
    - "registry.npmjs.org"

See Network Configuration for more information.

🔮 The oracle has spoken through Smoke Codex
_{Add label ready-for-aw to run again}

Copilot AI review requested due to automatic review settings July 16, 2026 19:41

Copilot started reviewing on behalf of lpcox July 16, 2026 19:42 View session

Copilot AI reviewed Jul 16, 2026

View reviewed changes

github-advanced-security AI found potential problems Jul 16, 2026

View reviewed changes

Comment thread scripts/ci/check-file-permissions.ts Fixed

lpcox added the ready-for-aw label Jul 16, 2026

lpcox had a problem deploying to aoai-model July 16, 2026 20:18 — with GitHub Actions Failure

github-actions Bot added smoke-claude smoke-copilot-pat labels Jul 16, 2026

lpcox temporarily deployed to aoai-model July 16, 2026 20:21 — with GitHub Actions Inactive

lpcox temporarily deployed to aoai-model July 16, 2026 20:22 — with GitHub Actions Inactive

github-actions Bot mentioned this pull request Jul 16, 2026

[aw] Smoke Copilot BYOK AOAI (api-key) failed #6312

Closed

github-actions Bot added the smoke-copilot-byok label Jul 16, 2026

github-actions Bot mentioned this pull request Jul 16, 2026

[aw] No-Op Runs #5883

Open

github-actions Bot mentioned this pull request Jul 16, 2026

[aw] Smoke Copilot BYOK AOAI (Entra) failed #6313

Closed

github-actions Bot added the build-test label Jul 16, 2026

lpcox merged commit 8a12aca into main Jul 16, 2026
135 of 137 checks passed

lpcox deleted the fix/chmod-mkdtemp-and-permissions-ci branch July 16, 2026 21:05

github-actions Bot mentioned this pull request Jul 17, 2026

chore: update model-to-API mapping (2026-07-17) #6317

Merged

Uh oh!

Conversation

lpcox commented Jul 16, 2026

Problem

Root Cause

Fix

1. src/services/agent-volumes/hosts-file.ts

2. New CI: .github/workflows/file-permissions-checker.yml

Testing

Related

Uh oh!

github-actions Bot commented Jul 16, 2026

✅ Coverage Check Passed

Overall Coverage

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Review details

Uh oh!

Uh oh!

github-actions Bot commented Jul 16, 2026

Uh oh!

github-actions Bot commented Jul 16, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

github-actions Bot commented Jul 16, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

github-actions Bot commented Jul 16, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

github-actions Bot commented Jul 16, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

github-actions Bot commented Jul 16, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

github-actions Bot commented Jul 16, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

github-actions Bot commented Jul 16, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

github-actions Bot commented Jul 16, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

github-actions Bot commented Jul 16, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

github-actions Bot commented Jul 16, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

github-actions Bot commented Jul 16, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

github-actions Bot commented Jul 16, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

github-actions Bot commented Jul 16, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

github-actions Bot commented Jul 16, 2026

Uh oh!

github-actions Bot commented Jul 16, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

github-actions Bot commented Jul 16, 2026

Smoke Test: Claude Engine Validation

Uh oh!

github-actions Bot commented Jul 16, 2026

Smoke Test: PAT Auth Validation

Uh oh!

github-actions Bot commented Jul 16, 2026

🔬 Smoke Test Results

Uh oh!

github-actions Bot commented Jul 16, 2026

Smoke Test: Copilot BYOK (Direct) Mode

Uh oh!

github-actions Bot commented Jul 16, 2026

1. `src/services/agent-volumes/hosts-file.ts`

2. New CI: `.github/workflows/file-permissions-checker.yml`

github-actions Bot commented Jul 16, 2026 •

edited

Loading

github-actions Bot commented Jul 16, 2026 •

edited

Loading

github-actions Bot commented Jul 16, 2026 •

edited

Loading

github-actions Bot commented Jul 16, 2026 •

edited

Loading

github-actions Bot commented Jul 16, 2026 •

edited

Loading

github-actions Bot commented Jul 16, 2026 •

edited

Loading

github-actions Bot commented Jul 16, 2026 •

edited

Loading

github-actions Bot commented Jul 16, 2026 •

edited

Loading

github-actions Bot commented Jul 16, 2026 •

edited

Loading

github-actions Bot commented Jul 16, 2026 •

edited

Loading

github-actions Bot commented Jul 16, 2026 •

edited

Loading

github-actions Bot commented Jul 16, 2026 •

edited

Loading

github-actions Bot commented Jul 16, 2026 •

edited

Loading

github-actions Bot commented Jul 16, 2026 •

edited

Loading