Description: Possible lock upgrade pattern where a cached value is read under RLock and rechecked only
after acquiring Lock without verifying it wasn't updated concurrently, which could allow
multiple goroutines to enter the recomputation path unnecessarily (double-check without
revalidation).
webassets.go [41-50]

entryPointAssetsCacheMu.RLock()
ret := entryPointAssetsCache
entryPointAssetsCacheMu.RUnlock()

if cfg.Env != setting.Dev && ret != nil {
	return ret, nil
}
entryPointAssetsCacheMu.Lock()
defer entryPointAssetsCacheMu.Unlock()

• Create ticket/issue

Follow the guide to enable codebase context checks.

Objective: Ensure all identifiers clearly express their purpose and intent, making code
self-documenting

Status: Passed

Objective: Ensure all data inputs are validated, sanitized, and handled securely to prevent
vulnerabilities

Status: Passed

Objective: To create a detailed and reliable record of critical system actions for security analysis
and compliance.

Status:
Missing audit logs: The new cache read/write paths add concurrency control around serving web assets but do
not log critical actions (e.g., cache hits/misses or updates), making it unclear if these
actions are auditable.

entryPointAssetsCacheMu.RLock()
ret := entryPointAssetsCache
entryPointAssetsCacheMu.RUnlock()

if cfg.Env != setting.Dev && ret != nil {
	return ret, nil
}
entryPointAssetsCacheMu.Lock()
defer entryPointAssetsCacheMu.Unlock()

Objective: Ensure comprehensive error handling that provides meaningful context and graceful
degradation

Status:
Unclear error paths: The added locking and early return change control flow around caching without confirming
that cache-miss paths and potential errors during asset computation are logged or handled
with context in this diff.

entryPointAssetsCacheMu.RLock()
ret := entryPointAssetsCache
entryPointAssetsCacheMu.RUnlock()

if cfg.Env != setting.Dev && ret != nil {
	return ret, nil
}
entryPointAssetsCacheMu.Lock()
defer entryPointAssetsCacheMu.Unlock()

var err error
var result *dtos.EntryPointAssets

Objective: To prevent the leakage of sensitive system information through error messages while
providing sufficient detail for internal debugging.

Status:
Error exposure unknown: The diff does not show user-facing error handling changes; without visibility into
returned errors from this function, it is unclear whether sensitive details could be
exposed.

var err error
var result *dtos.EntryPointAssets

Objective: To ensure logs are useful for debugging and auditing without exposing sensitive
information like PII, PHI, or cardholder data.

Status:
No logging context: The new cache logic does not add structured logs for cache decisions or errors, and the
diff provides no evidence that logs (if any elsewhere) avoid sensitive data.

entryPointAssetsCacheMu.RLock()
ret := entryPointAssetsCache
entryPointAssetsCacheMu.RUnlock()

if cfg.Env != setting.Dev && ret != nil {
	return ret, nil
}
entryPointAssetsCacheMu.Lock()
defer entryPointAssetsCacheMu.Unlock()

The current RWMutex implementation has a double-checked locking bug, allowing
concurrent re-computation of assets. Replace it with sync.Once for a safer and
more idiomatic one-time initialization.

Examples:

func GetWebAssets(ctx context.Context, cfg *setting.Cfg, license licensing.Licensing) (*dtos.EntryPointAssets, error) {
	entryPointAssetsCacheMu.RLock()
	ret := entryPointAssetsCache
	entryPointAssetsCacheMu.RUnlock()

	if cfg.Env != setting.Dev && ret != nil {
		return ret, nil
	}
	entryPointAssetsCacheMu.Lock()
	defer entryPointAssetsCacheMu.Unlock()

 ... (clipped 22 lines)

Solution Walkthrough:

Before:

var (
  entryPointAssetsCacheMu sync.RWMutex
  entryPointAssetsCache   *dtos.EntryPointAssets
)

func GetWebAssets(...) (*dtos.EntryPointAssets, error) {
  entryPointAssetsCacheMu.RLock()
  ret := entryPointAssetsCache
  entryPointAssetsCacheMu.RUnlock()

  if cfg.Env != setting.Dev && ret != nil {
    return ret, nil
  }
  entryPointAssetsCacheMu.Lock()
  defer entryPointAssetsCacheMu.Unlock()

  // ... asset computation logic ...
  // This part is executed by multiple goroutines if they all miss the cache.
  entryPointAssetsCache = result
  return entryPointAssetsCache, err
}

After:

var (
  assetsOnce            sync.Once
  entryPointAssetsCache *dtos.EntryPointAssets
  initErr               error
)

func GetWebAssets(...) (*dtos.EntryPointAssets, error) {
  if cfg.Env == setting.Dev {
    return computeWebAssets(...) // Always recompute in dev
  }

  assetsOnce.Do(func() {
    // This function is guaranteed to run exactly once.
    entryPointAssetsCache, initErr = computeWebAssets(...)
  })

  return entryPointAssetsCache, initErr
}

To fix a race condition in the double-checked locking implementation, re-check
if the cache is populated immediately after acquiring the write lock.

pkg/api/webassets/webassets.go [41-70]

 	entryPointAssetsCacheMu.RLock()
 	ret := entryPointAssetsCache
 	entryPointAssetsCacheMu.RUnlock()
 
 	if cfg.Env != setting.Dev && ret != nil {
 		return ret, nil
 	}
 	entryPointAssetsCacheMu.Lock()
 	defer entryPointAssetsCacheMu.Unlock()
 
+	// Re-check after acquiring write lock to prevent race condition
+	if entryPointAssetsCache != nil {
+		return entryPointAssetsCache, nil
+	}
+
 	var err error
 	var result *dtos.EntryPointAssets
 ...
 	}
 
 	entryPointAssetsCache = result
 	return entryPointAssetsCache, err

[To ensure code accuracy, apply this suggestion manually]