What causes "too many levels of symbolic links" in crowdsecurity/crowdsec?

Find and remove the symlink cycle: 'find /path/to/hub -type l -exec ls -l {} \;' and delete the looping link

too many levels of symbolic links

Error message

too many levels of symbolic links

What it means

resolveSymlink walks a path resolving symlinks with an iteration cap; if it exceeds the maximum number of link levels without reaching a real file it returns 'too many levels of symbolic links'. This guards against symlink loops during plugin/hub item installation.

Source

Thrown at pkg/cwhub/path.go:42

		if fi.Mode()&os.ModeSymlink == 0 {
			// found the target
			return cur, nil
		}

		target, err := os.Readlink(cur)
		if err != nil {
			return "", err
		}

		// relative to the link's directory?
		if !filepath.IsAbs(target) {
			target = filepath.Join(filepath.Dir(cur), target)
		}
		cur = target
	}

	return "", errors.New("too many levels of symbolic links")
}

// isPathInside checks if a path is inside the given directory
func isPathInside(path, dir string) (bool, error) {
	absFile, err := filepath.Abs(path)
	if err != nil {
		return false, err
	}

	absDir, err := filepath.Abs(dir)
	if err != nil {
		return false, err
	}

	rel, err := filepath.Rel(absDir, absFile)
	if err != nil {
		return false, err
	}

View on GitHub (pinned to 909b515798)

Solutions

Find and remove the symlink cycle: 'find /path/to/hub -type l -exec ls -l {} \;' and delete the looping link
Replace the circular symlink with the real file or a direct path
Reinstall the affected hub item ('cscli hub item reinstall <item>')

Example fix

// before
ln -s /etc/crowdsec/hub/parsers/syslog /etc/crowdsec/hub/parsers/syslog
// after
ln -s /etc/crowdsec/hub/parsers/syslog/remote_syslog.yaml /etc/crowdsec/hub/parsers/syslog-current

Defensive patterns

Strategy: validation

Validate before calling

// detect symlink loops before installing items
resolved, err := filepath.EvalSymlinks(targetPath)
if err != nil { return fmt.Errorf("bad symlink at %s: %w", targetPath, err) }

Type guard

func isSymlinkLoop(p string) bool { _, err := filepath.EvalSymlinks(p); return err != nil }

Try / catch

spec, err := cwhub newItemSpec(...)
if err != nil && strings.Contains(err.Error(), "too many levels of symbolic links") {
    return fmt.Errorf("symlink loop in hub item path %s", path)
}

Prevention

Never create symlinks pointing at their own parent directory inside hub dirs
Audit hub directories for circular links after restores or manual edits
Reinstall items via cscli rather than hand-symlinking

When it happens

Trigger: newItemSpec resolving an item path whose symlink chain loops (A -> B -> A) or is longer than the iteration limit; called during item loading and exercised by TestResolveSymlink_Relative.

Common situations: Hand-made symlink cycles in the hub directory; a user symlinked a data dir onto itself via bind mounts or misconfigured dotfiles; restoring a backup that recreated circular links.

Related errors

AI-assisted analysis of crowdsecurity/crowdsec@909b515798 (2026-09-06). Data as JSON: /api/errors/a5d1b4cc092c5c5f. Report an issue: GitHub.