Avoid UB when reading Wii volume names

4 files changed, 15 insertions, 16 deletions

diff --git a/Source/Core/DiscIO/Volume.cpp b/Source/Core/DiscIO/Volume.cpp
index 9ae87466e2..e95a2b746f 100644
--- a/Source/Core/DiscIO/Volume.cpp
+++ b/Source/Core/DiscIO/Volume.cpp
@@ -26,17 +26,15 @@ namespace DiscIO
 const IOS::ES::TicketReader Volume::INVALID_TICKET{};
 const IOS::ES::TMDReader Volume::INVALID_TMD{};
 
-std::map<Language, std::string> Volume::ReadWiiNames(const std::vector<u8>& data)
+std::map<Language, std::string> Volume::ReadWiiNames(const std::vector<char16_t>& data)
 {
   std::map<Language, std::string> names;
   for (size_t i = 0; i < NUMBER_OF_LANGUAGES; ++i)
   {
-    size_t name_start = NAME_BYTES_LENGTH * i;
-    size_t name_end = name_start + NAME_BYTES_LENGTH;
-    if (data.size() >= name_end)
+    const size_t name_start = NAME_CHARS_LENGTH * i;
+    if (name_start + NAME_CHARS_LENGTH <= data.size())
     {
-      std::string name = UTF16BEToUTF8(reinterpret_cast<const char16_t*>(data.data() + name_start),
-                                       NAME_STRING_LENGTH);
+      const std::string name = UTF16BEToUTF8(data.data() + name_start, NAME_CHARS_LENGTH);
       if (!name.empty())
         names[static_cast<Language>(i)] = name;
     }
diff --git a/Source/Core/DiscIO/Volume.h b/Source/Core/DiscIO/Volume.h
index 67609ddabe..f7172db6cc 100644
--- a/Source/Core/DiscIO/Volume.h
+++ b/Source/Core/DiscIO/Volume.h
@@ -116,11 +116,12 @@ protected:
   }
 
   virtual u32 GetOffsetShift() const { return 0; }
-  static std::map<Language, std::string> ReadWiiNames(const std::vector<u8>& data);
+  static std::map<Language, std::string> ReadWiiNames(const std::vector<char16_t>& data);
 
   static const size_t NUMBER_OF_LANGUAGES = 10;
-  static const size_t NAME_STRING_LENGTH = 42;
-  static const size_t NAME_BYTES_LENGTH = NAME_STRING_LENGTH * sizeof(u16);
+  static const size_t NAME_CHARS_LENGTH = 42;
+  static const size_t NAME_BYTES_LENGTH = NAME_CHARS_LENGTH * sizeof(char16_t);
+  static const size_t NAMES_TOTAL_CHARS = NAME_CHARS_LENGTH * NUMBER_OF_LANGUAGES;
   static const size_t NAMES_TOTAL_BYTES = NAME_BYTES_LENGTH * NUMBER_OF_LANGUAGES;
 
   static const IOS::ES::TicketReader INVALID_TICKET;
diff --git a/Source/Core/DiscIO/VolumeWad.cpp b/Source/Core/DiscIO/VolumeWad.cpp
index d09baf1f6a..2d98986f81 100644
--- a/Source/Core/DiscIO/VolumeWad.cpp
+++ b/Source/Core/DiscIO/VolumeWad.cpp
@@ -138,10 +138,10 @@ std::map<Language, std::string> VolumeWAD::GetLongNames() const
   if (!m_tmd.IsValid() || !IOS::ES::IsChannel(m_tmd.GetTitleId()))
     return {};
 
-  std::vector<u8> name_data(NAMES_TOTAL_BYTES);
-  if (!Read(m_opening_bnr_offset + 0x9C, NAMES_TOTAL_BYTES, name_data.data()))
+  std::vector<char16_t> names(NAMES_TOTAL_CHARS);
+  if (!Read(m_opening_bnr_offset + 0x9C, NAMES_TOTAL_BYTES, reinterpret_cast<u8*>(names.data())))
     return std::map<Language, std::string>();
-  return ReadWiiNames(name_data);
+  return ReadWiiNames(names);
 }
 
 std::vector<u32> VolumeWAD::GetBanner(int* width, int* height) const
diff --git a/Source/Core/DiscIO/VolumeWii.cpp b/Source/Core/DiscIO/VolumeWii.cpp
index 2158e71f1a..bc0c410c13 100644
--- a/Source/Core/DiscIO/VolumeWii.cpp
+++ b/Source/Core/DiscIO/VolumeWii.cpp
@@ -302,10 +302,10 @@ std::string VolumeWii::GetInternalName(const Partition& partition) const
 
 std::map<Language, std::string> VolumeWii::GetLongNames() const
 {
-  std::vector<u8> opening_bnr(NAMES_TOTAL_BYTES);
-  opening_bnr.resize(ReadFile(*this, GetGamePartition(), "opening.bnr", opening_bnr.data(),
-                              opening_bnr.size(), 0x5C));
-  return ReadWiiNames(opening_bnr);
+  std::vector<char16_t> names(NAMES_TOTAL_CHARS);
+  names.resize(ReadFile(*this, GetGamePartition(), "opening.bnr",
+                        reinterpret_cast<u8*>(names.data()), NAMES_TOTAL_BYTES, 0x5C));
+  return ReadWiiNames(names);
 }
 
 std::vector<u32> VolumeWii::GetBanner(int* width, int* height) const