closes https://github.com/assimp/assimp/issues/1459: fix out-of-boundary access error

code/SIBImporter.cpp

@@ -176,36 +176,29 @@ static void UnknownChunk(StreamReaderLE* stream, const SIBChunk& chunk)
 }
 
 // Reads a UTF-16LE string and returns it at UTF-8.
-static aiString ReadString(StreamReaderLE* stream, uint32_t numWChars)
-{
-    if ( 0 == numWChars ) {
+static aiString ReadString(StreamReaderLE *stream, uint32_t numWChars) {
+    if ( nullptr == stream || 0 == numWChars ) {
         static const aiString empty;
         return empty;
     }
+
     // Allocate buffers (max expansion is 1 byte -> 4 bytes for UTF-8)
-    //UTF16* temp = new UTF16[numWChars];
     std::vector<unsigned char> str;
-    str.reserve(numWChars * 4 + 1);
-    //unsigned char* str = new unsigned char[numWChars * 4 + 1];
-    uint16_t *temp = new uint16_t[numWChars];
-    for (uint32_t n=0;n<numWChars;n++)
-        temp[n] = stream->GetU2();
+    str.reserve( numWChars * 4 + 1 );
+    uint16_t *temp = new uint16_t[ numWChars ];
+    for ( uint32_t n = 0; n < numWChars; ++n ) {
+        temp[ n ] = stream->GetU2();
+    }
 
     // Convert it and NUL-terminate.
-    //const UTF16 *start = temp, *end = temp + numWChars;
+    const uint16_t *start( temp ), *end( temp + numWChars );
+    utf8::utf16to8( start, end, back_inserter( str ) );
+    str[ str.size() - 1 ] = '\0';
 
-    const uint16_t *start = temp, *end = temp + numWChars;
-    utf8::utf16to8(start, end, back_inserter(str));
-
-    //UTF8 *dest = str, *limit = str + numWChars*4;
-    //ConvertUTF16toUTF8(&start, end, &dest, limit, lenientConversion);
-    //*dest = '\0';
-
-    str[str.size()] = '\0';
     // Return the final string.
     aiString result = aiString((const char *)&str[0]);
-    //delete[] str;
     delete[] temp;
+
     return result;
 }
 
@@ -223,26 +216,26 @@ SIBImporter::~SIBImporter() {
 
 // ------------------------------------------------------------------------------------------------
 // Returns whether the class can handle the format of the given file.
-bool SIBImporter::CanRead( const std::string& pFile, IOSystem* /*pIOHandler*/, bool /*checkSig*/) const
-{
+bool SIBImporter::CanRead( const std::string& pFile, IOSystem* /*pIOHandler*/, bool /*checkSig*/) const {
     return SimpleExtensionCheck(pFile, "sib");
 }
 
 // ------------------------------------------------------------------------------------------------
-const aiImporterDesc* SIBImporter::GetInfo () const
-{
+const aiImporterDesc* SIBImporter::GetInfo () const {
     return &desc;
 }
 
 // ------------------------------------------------------------------------------------------------
-static void ReadVerts(SIBMesh* mesh, StreamReaderLE* stream, uint32_t count)
-{
-    mesh->pos.resize(count);
+static void ReadVerts(SIBMesh* mesh, StreamReaderLE* stream, uint32_t count) {
+    if ( nullptr == mesh || nullptr == stream ) {
+        return;
+    }
 
-    for (uint32_t n=0;n<count;n++) {
-        mesh->pos[n].x = stream->GetF4();
-        mesh->pos[n].y = stream->GetF4();
-        mesh->pos[n].z = stream->GetF4();
+    mesh->pos.resize(count);
+    for ( uint32_t n=0; n<count; ++n ) {
+        mesh->pos[ n ].x = stream->GetF4();
+        mesh->pos[ n ].y = stream->GetF4();
+        mesh->pos[ n ].z = stream->GetF4();
     }
 }
 

code/StreamReader.h

@@ -291,15 +291,11 @@ private:
             throw DeadlyImportError("End of file or stream limit was reached");
         }
 
-///*#ifdef __arm__
         T f;
         ::memcpy (&f, current, sizeof(T));
-//#else*/
-//        T f = *((const T*)current);
-//#endif
-        Intern :: Getter<SwapEndianess,T,RuntimeSwitch>() (&f,le);
-
+        Intern::Getter<SwapEndianess,T,RuntimeSwitch>() (&f,le);
         current += sizeof(T);
+
         return f;
     }