What causes "systemdservice_create_none" in shadow1ng/fscan?

Run with write permission on the unit directory (root or writable ~/.config/systemd/user)

systemdservice_create_none

Error message

systemdservice_create_none

What it means

Guard in createSystemdServices: none of the candidate systemd unit files could be written to the system directory (every os.WriteFile failed, e.g. missing privileges or read-only filesystem). Since no service was planted, the function reports total failure instead of returning an empty list.

Source

Thrown at plugins/local/systemdservice.go:276

Type=oneshot
User=root
ExecStart=%s
StandardOutput=null
StandardError=null
`, execPath),
		},
	}

	var created []string
	for _, service := range services {
		servicePath := filepath.Join(systemDir, service.name)
		if err := os.WriteFile(servicePath, []byte(service.content), 0644); err == nil {
			created = append(created, service.name)
		}
	}

	if len(created) == 0 {
		return nil, fmt.Errorf("%s", i18n.GetText("systemdservice_create_none"))
	}

	return created, nil
}

// enableAndStartServices 启用并启动服务
func (p *SystemdServicePlugin) enableAndStartServices(serviceFiles []string) error {
	var errors []string

	for _, serviceName := range serviceFiles {
		// 重新加载systemd配置
		_ = exec.Command("systemctl", "daemon-reload").Run()

		// 启用服务
		if err := exec.Command("systemctl", "enable", serviceName).Run(); err != nil {
			errors = append(errors, fmt.Sprintf("enable %s: %v", serviceName, err))
		}

View on GitHub (pinned to 95cc12e753)

Solutions

Run with write permission on the unit directory (root or writable ~/.config/systemd/user)
Check disk space and mount status (df -h, mount | grep ro)
Log per-file WriteFile errors during the loop so the actual cause is visible instead of a generic none-created error

Example fix

// before
if err := os.WriteFile(servicePath, []byte(service.content), 0644); err == nil {
    created = append(created, service.name)
}
// after
if err := os.WriteFile(servicePath, []byte(service.content), 0644); err != nil {
    return nil, fmt.Errorf("write %s: %w", servicePath, err)
}
created = append(created, service.name)

Defensive patterns

Strategy: validation

Validate before calling

testPath := filepath.Join(unitDir, "writetest")
if err := os.WriteFile(testPath, []byte("x"), 0644); err != nil {
    return fmt.Errorf("unit dir not writable: %w", err)
}
_ = os.Remove(testPath)

Prevention

Verify write access to the unit directory before writing units
Log individual WriteFile errors instead of collapsing to a generic error
Ensure adequate disk space and rw mounts

When it happens

Trigger: All unit file writes failed — service directory exists but is not writable, wrong path, or disk full.

Common situations: Non-root user writing to /etc/systemd/system; typo'd unit directory from a previous failed step; read-only root filesystem in containers.

Understand the failure class

Background: "failed to write file", "Could not save figure", "Error saving remote file" — file write failed: causes and fixes across languages and libraries — this error's family across 38 libraries.

Related errors

AI-assisted analysis of shadow1ng/fscan@95cc12e753 (2026-09-06). Data as JSON: /api/errors/cd697c24e8ee78af. Report an issue: GitHub.