[lldb] Fix Scripted ProcessLaunchInfo Argument nullptr deref

This patch adds a new `StructuredData::Dictionary` constructor that
takes a `StructuredData::ObjectSP` as an argument. This is used to pass
the opaque_ptr from the `SBStructuredData` used to initialize a
ScriptedProecss, to the `ProcessLaunchInfo` class.

This also updates `SBLaunchInfo::SetScriptedProcessDictionary` to
reflect the formentionned changes which solves the nullptr deref.

Differential Revision: https://reviews.llvm.org/D112107

Signed-off-by: Med Ismail Bennani <[email protected]>

Author: medismailben

lldb/include/lldb/Core/StructuredDataImpl.h

@@ -152,6 +152,8 @@ class StructuredDataImpl {
     return (::snprintf(dst, dst_len, "%s", result.data()));
   }
 
+  StructuredData::ObjectSP GetObjectSP() const { return m_data_sp; }
+
 private:
   lldb::StructuredDataPluginWP m_plugin_wp;
   StructuredData::ObjectSP m_data_sp;

lldb/include/lldb/Utility/StructuredData.h

@@ -353,6 +353,17 @@ class StructuredData {
   public:
     Dictionary() : Object(lldb::eStructuredDataTypeDictionary), m_dict() {}
 
+    Dictionary(ObjectSP obj_sp)
+        : Object(lldb::eStructuredDataTypeDictionary), m_dict() {
+      if (!obj_sp || obj_sp->GetType() != lldb::eStructuredDataTypeDictionary) {
+        SetType(lldb::eStructuredDataTypeInvalid);
+        return;
+      }
+
+      Dictionary *dict = obj_sp->GetAsDictionary();
+      m_dict = dict->m_dict;
+    }
+
     ~Dictionary() override = default;
 
     size_t GetSize() const { return m_dict.size(); }

lldb/source/API/SBLaunchInfo.cpp

@@ -380,16 +380,18 @@ lldb::SBStructuredData SBLaunchInfo::GetScriptedProcessDictionary() const {
 void SBLaunchInfo::SetScriptedProcessDictionary(lldb::SBStructuredData dict) {
   LLDB_RECORD_METHOD(void, SBLaunchInfo, SetScriptedProcessDictionary,
                      (lldb::SBStructuredData), dict);
+  if (!dict.IsValid() || !dict.m_impl_up)
+    return;
 
-  SBStream stream;
-  SBError error = dict.GetAsJSON(stream);
+  StructuredData::ObjectSP obj_sp = dict.m_impl_up->GetObjectSP();
 
-  if (error.Fail())
+  if (!obj_sp)
     return;
 
-  StructuredData::DictionarySP dict_sp;
-  llvm::json::OStream s(stream.ref().AsRawOstream());
-  dict_sp->Serialize(s);
+  StructuredData::DictionarySP dict_sp =
+      std::make_shared<StructuredData::Dictionary>(obj_sp);
+  if (!dict_sp || dict_sp->GetType() == lldb::eStructuredDataTypeInvalid)
+    return;
 
   m_opaque_sp->SetScriptedProcessDictionarySP(dict_sp);
 }

lldb/source/Plugins/Process/scripted/ScriptedProcess.cpp

@@ -111,7 +111,7 @@ ScriptedProcess::ScriptedProcess(
 
   StructuredData::GenericSP object_sp = GetInterface().CreatePluginObject(
       m_scripted_process_info.GetClassName().c_str(), exe_ctx,
-      m_scripted_process_info.GetDictionarySP());
+      m_scripted_process_info.GetArgsSP());
 
   if (!object_sp || !object_sp->IsValid()) {
     error.SetErrorStringWithFormat("ScriptedProcess::%s () - ERROR: %s",

lldb/source/Plugins/Process/scripted/ScriptedProcess.h

@@ -25,17 +25,15 @@ class ScriptedProcess : public Process {
   public:
     ScriptedProcessInfo(const ProcessLaunchInfo &launch_info) {
       m_class_name = launch_info.GetScriptedProcessClassName();
-      m_dictionary_sp = launch_info.GetScriptedProcessDictionarySP();
+      m_args_sp = launch_info.GetScriptedProcessDictionarySP();
     }
 
     std::string GetClassName() const { return m_class_name; }
-    StructuredData::DictionarySP GetDictionarySP() const {
-      return m_dictionary_sp;
-    }
+    StructuredData::DictionarySP GetArgsSP() const { return m_args_sp; }
 
   private:
     std::string m_class_name;
-    StructuredData::DictionarySP m_dictionary_sp;
+    StructuredData::DictionarySP m_args_sp;
   };
 
 public:

lldb/source/Plugins/Process/scripted/ScriptedThread.cpp

@@ -55,7 +55,7 @@ ScriptedThread::ScriptedThread(ScriptedProcess &process, Status &error)
   StructuredData::GenericSP object_sp =
       scripted_thread_interface->CreatePluginObject(
           class_name->c_str(), exe_ctx,
-          process.m_scripted_process_info.GetDictionarySP());
+          process.m_scripted_process_info.GetArgsSP());
   if (!object_sp || !object_sp->IsValid()) {
     error.SetErrorString("Failed to create valid script object");
     return;