Fuzzing: Don't explicitly restrict sizes before loading images

Since Qt 6.0, QImageIOHandlers by default take care of this themselves
by not allocating more than 128 MiB for an image.

This change will not significantly reduce code coverage of the fuzzer
because QImage::loadFromData() calls QImageReader::read() which does
everything QImageReader::size() does except for returning the read size
in the end. On the other hand, it will speed up the execution because
the same image will not be read twice by different QImageReaders anymore.

Change-Id: Iab63d9e5ec02fbe5765fbf7ccb0b82896ec37692
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

1 files changed, 2 insertions, 11 deletions

diff --git a/tests/libfuzzer/gui/image/qimage/loadfromdata/main.cpp b/tests/libfuzzer/gui/image/qimage/loadfromdata/main.cpp
index 54d1ed0ee6..4a34d8fe5d 100644
--- a/tests/libfuzzer/gui/image/qimage/loadfromdata/main.cpp
+++ b/tests/libfuzzer/gui/image/qimage/loadfromdata/main.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2020 The Qt Company Ltd.
+** Copyright (C) 2022 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the test suite of the Qt Toolkit.
@@ -26,11 +26,8 @@
 **
 ****************************************************************************/
 
-#include <QBuffer>
 #include <QGuiApplication>
 #include <QImage>
-#include <QImageReader>
-#include <QSize>
 #include <QtGlobal>
 
 // silence warnings
@@ -44,12 +41,6 @@ extern "C" int LLVMFuzzerTestOneInput(const char *Data, size_t Size) {
     static char arg3[] = "minimal";
     static char *argv[] = {arg1, arg2, arg3, nullptr};
     static QGuiApplication qga(argc, argv);
-    QByteArray input(QByteArray::fromRawData(Data, Size));
-    QBuffer buf(&input);
-    const QSize size = QImageReader(&buf).size();
-    // Don't try to load huge valid images.
-    // They are justified in using huge memory.
-    if (!size.isValid() || uint64_t(size.width()) * size.height() < 64 * 1024 * 1024)
-        QImage().loadFromData(input);
+    QImage().loadFromData(QByteArray::fromRawData(Data, Size));
     return 0;
 }