Fix Heap-buffer-overflow in Q3DImporter::InternReadFile (#6370)

Checks if multiplying texture width and height would overflow before
performing the operation. This avoids incorrect memory allocations and
potential crashes with very large textures.

Fixes #6358

Co-authored-by: Kim Kulling <kimkulling@users.noreply.github.com>

code/AssetLib/Q3D/Q3DLoader.cpp

@@ -55,6 +55,8 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <assimp/DefaultLogger.hpp>
 #include <assimp/IOSystem.hpp>
 
+#include <limits>
+
 namespace Assimp {
 
 static constexpr aiImporterDesc desc = {
@@ -309,6 +311,11 @@ void Q3DImporter::InternReadFile(const std::string &pFile,
                     throw DeadlyImportError("Quick3D: Invalid texture. Width or height is zero");
                 }
 
+                const unsigned int uint_max = std::numeric_limits<unsigned int>::max();
+                if (tex->mWidth > (uint_max / tex->mHeight)) {
+                    throw DeadlyImportError("Quick3D: Texture dimensions are too large, resulting in overflow.");
+                }
+
                 unsigned int mul = tex->mWidth * tex->mHeight;
                 aiTexel *begin = tex->pcData = new aiTexel[mul];
                 aiTexel *const end = &begin[mul - 1] + 1;