Bug 1923017 - Fix null ptr deref in CacheFileIOManager::Read a=diannaS

Original Revision: https://phabricator.services.mozilla.com/D253658

Differential Revision: https://phabricator.services.mozilla.com/D259939

netwerk/cache2/CacheFileIOManager.cpp

@@ -1953,6 +1953,10 @@ nsresult CacheFileIOManager::Read(CacheFileHandle* aHandle, int64_t aOffset,
     return NS_ERROR_NOT_INITIALIZED;
   }
 
+  if (!aHandle) {
+    return NS_ERROR_NULL_POINTER;
+  }
+
   nsresult rv;
   RefPtr<CacheFileIOManager> ioMan = gInstance;