Merge pull request #835 from barnabasdomozi/fix_heap_use_after_free

Fix heap use-after-free in shared object loading

Author: mcserep

parser/src/pluginhandler.cpp

@@ -52,8 +52,17 @@ void PluginHandler::loadPlugins(std::vector<std::string>& skipParserList_)
         skipParserList_.end())
       {
         std::string dynamicLibraryPath = dirIter->path().string();
+        int dlopenFlags = RTLD_NOW;
+        if (filename == "pythonparser")
+        {
+          // RTLD_GLOBAL:
+          // The symbols defined by this shared object will be made available for
+          // symbol resolution of subsequently loaded shared objects.
+          dlopenFlags |= RTLD_GLOBAL;
+        }
+
         _dynamicLibraries[filename] = util::DynamicLibraryPtr(
-          new util::DynamicLibrary(dynamicLibraryPath));
+          new util::DynamicLibrary(dynamicLibraryPath, dlopenFlags));
       }
       else
       {

util/include/util/dynamiclibrary.h

@@ -21,7 +21,7 @@ class DynamicLibrary
 {
 public:
   DynamicLibrary(void* handle_);
-  DynamicLibrary(const std::string& path_);
+  DynamicLibrary(const std::string& path_, int dlopen_flags_ = RTLD_NOW);
 
   ~DynamicLibrary();
 

util/src/dynamiclibrary.cpp

@@ -16,7 +16,7 @@ std::string DynamicLibrary::extension()
 
 DynamicLibrary::DynamicLibrary(void* handle_) : _handle(handle_){}
 
-DynamicLibrary::DynamicLibrary(const std::string& path_)
+DynamicLibrary::DynamicLibrary(const std::string& path_, int dlopen_flags_)
 {
   if (path_.empty())
   {
@@ -37,7 +37,7 @@ DynamicLibrary::DynamicLibrary(const std::string& path_)
     throw std::runtime_error(ss.str());
   }
 #else
-  _handle = ::dlopen(path_.c_str(), RTLD_NOW | RTLD_GLOBAL);
+  _handle = ::dlopen(path_.c_str(), dlopen_flags_);
   if (!_handle)
   {
     const char *dlError = ::dlerror();