From 7e4fdf7669dcef193f27008a3022e3ab09904468 Mon Sep 17 00:00:00 2001
From: x1nixmzeng <x1nixmzeng@live.co.uk>
Date: Sat, 9 Jan 2016 01:19:05 +0000
Subject: [PATCH] Fixed rare crash when accessing library import by name

The library name index may only be 8-bits.

This bug was not present in the previous implementation due to a bitmask
(0xFF) - see
https://github.com/benvanik/xenia/blob/ea99ba8e3bbac03386c95efe1496d5f4b03f5456/src/xenia/kernel/util/xex2.cc#L272
---
 src/xenia/cpu/xex_module.cc     | 6 ++++--
 src/xenia/kernel/user_module.cc | 5 +++--
 src/xenia/kernel/util/xex2.cc   | 3 ++-
 3 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/xenia/cpu/xex_module.cc b/src/xenia/cpu/xex_module.cc
index 860b204b5..4d5e6801b 100644
--- a/src/xenia/cpu/xex_module.cc
+++ b/src/xenia/cpu/xex_module.cc
@@ -260,10 +260,12 @@ bool XexModule::Load(const std::string& name, const std::string& path,
   auto libraries_ptr = reinterpret_cast<uint8_t*>(opt_import_header) +
                        opt_import_header->string_table_size + 12;
   uint32_t library_offset = 0;
-  for (uint32_t i = 0; i < opt_import_header->library_count; i++) {
+  uint32_t library_count = opt_import_header->library_count;
+  for (uint32_t i = 0; i < library_count; i++) {
     auto library =
         reinterpret_cast<xex2_import_library*>(libraries_ptr + library_offset);
-    SetupLibraryImports(string_table[library->name_index], library);
+    SetupLibraryImports(string_table[library->name_index % library_count],
+                        library);
     library_offset += library->size;
   }
 
diff --git a/src/xenia/kernel/user_module.cc b/src/xenia/kernel/user_module.cc
index 07894984d..b831c8adb 100644
--- a/src/xenia/kernel/user_module.cc
+++ b/src/xenia/kernel/user_module.cc
@@ -475,10 +475,11 @@ void UserModule::Dump() {
             reinterpret_cast<const uint8_t*>(opt_import_libraries) +
             opt_import_libraries->string_table_size + 12;
         uint32_t library_offset = 0;
-        for (uint32_t l = 0; l < opt_import_libraries->library_count; l++) {
+        uint32_t library_count = opt_import_libraries->library_count;
+        for (uint32_t l = 0; l < library_count; l++) {
           auto library = reinterpret_cast<const xex2_import_library*>(
               libraries + library_offset);
-          auto name = string_table[library->name_index];
+          auto name = string_table[library->name_index % library_count];
           sb.AppendFormat("    %s - %d imports\n", name,
                           (uint16_t)library->count);
 
diff --git a/src/xenia/kernel/util/xex2.cc b/src/xenia/kernel/util/xex2.cc
index dbbea04f3..2bfe11ca3 100644
--- a/src/xenia/kernel/util/xex2.cc
+++ b/src/xenia/kernel/util/xex2.cc
@@ -285,7 +285,8 @@ int xe_xex2_read_header(const uint8_t* addr, const size_t length,
           library->version.value = src_library->version.value;
           library->min_version.value = src_library->version_min.value;
 
-          std::strncpy(library->name, string_table[src_library->name_index],
+          std::strncpy(library->name,
+                       string_table[src_library->name_index % count],
                        xe::countof(library->name));
 
           library->record_count = src_library->count;