From eaf0587dd8b8bb2e66a7c83ef142eb5990f3839b Mon Sep 17 00:00:00 2001
From: Malcolm Tyrrell <matyrr@microsoft.com>
Date: Thu, 30 Jul 2020 14:56:01 +0100
Subject: [PATCH] FBX Version/Size Check

---
 code/AssetLib/FBX/FBXBinaryTokenizer.cpp | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/code/AssetLib/FBX/FBXBinaryTokenizer.cpp b/code/AssetLib/FBX/FBXBinaryTokenizer.cpp
index 719b928bc..bbb3e5434 100644
--- a/code/AssetLib/FBX/FBXBinaryTokenizer.cpp
+++ b/code/AssetLib/FBX/FBXBinaryTokenizer.cpp
@@ -54,6 +54,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <assimp/Exceptional.h>
 #include <assimp/ByteSwapper.h>
 #include <assimp/DefaultLogger.hpp>
+#include <assimp/StringUtils.h>
 
 namespace Assimp {
 namespace FBX {
@@ -456,11 +457,21 @@ void TokenizeBinary(TokenList& output_tokens, const char* input, size_t length)
 	ASSIMP_LOG_DEBUG_F("FBX version: ", version);
 	const bool is64bits = version >= 7500;
     const char *end = input + length;
-    while (cursor < end ) {
-		if (!ReadScope(output_tokens, input, cursor, input + length, is64bits)) {
-            break;
+    try
+    {
+        while (cursor < end ) {
+		    if (!ReadScope(output_tokens, input, cursor, input + length, is64bits)) {
+                break;
+            }
         }
     }
+    catch (const DeadlyImportError& e)
+    {
+        if ((sizeof(size_t) > 4) && !is64bits && (length > std::numeric_limits<std::uint32_t>::max())) {
+            throw DeadlyImportError("The FBX is invalid. This may be because the content is too big for this older version (" + to_string(version) + ") of the FBX format. (" + e.what() + ")");
+        }
+        throw;
+    }
 }
 
 } // !FBX