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authorweili <weili@chromium.org>2016-08-11 19:43:58 -0700
committerCommit bot <commit-bot@chromium.org>2016-08-11 19:43:58 -0700
commit229d05df5bc5deb3890b26b614113c25d9b6935e (patch)
tree1491fa61aab052ac7784ef90c8a7b60368daac27 /core/fxge/dib
parent2736276deff3abef9d6b226eb9f585abe1384591 (diff)
downloadpdfium-229d05df5bc5deb3890b26b614113c25d9b6935e.tar.xz
Fix an integer overflow in CStretchEngine constructor
When the source bitmap's width and height are large, the multiplication could easily overflow a signed integer. Change to use 'long long' type for calculation to avoid that. BUG=chromium:635663 Review-Url: https://codereview.chromium.org/2240723002
Diffstat (limited to 'core/fxge/dib')
-rw-r--r--core/fxge/dib/fx_dib_engine.cpp4
-rw-r--r--core/fxge/dib/fx_dib_engine_unittest.cpp30
2 files changed, 32 insertions, 2 deletions
diff --git a/core/fxge/dib/fx_dib_engine.cpp b/core/fxge/dib/fx_dib_engine.cpp
index 520148fc77..88b0d4b271 100644
--- a/core/fxge/dib/fx_dib_engine.cpp
+++ b/core/fxge/dib/fx_dib_engine.cpp
@@ -306,8 +306,8 @@ CStretchEngine::CStretchEngine(IFX_ScanlineComposer* pDestBitmap,
FX_BOOL bInterpol =
flags & FXDIB_INTERPOL || flags & FXDIB_BICUBIC_INTERPOL;
if (!bInterpol && FXSYS_abs(dest_width) != 0 &&
- FXSYS_abs(dest_height) <
- m_SrcWidth * m_SrcHeight * 8 / FXSYS_abs(dest_width)) {
+ FXSYS_abs(dest_height) / 8 < static_cast<long long>(m_SrcWidth) *
+ m_SrcHeight / FXSYS_abs(dest_width)) {
flags = FXDIB_INTERPOL;
}
m_Flags = flags;
diff --git a/core/fxge/dib/fx_dib_engine_unittest.cpp b/core/fxge/dib/fx_dib_engine_unittest.cpp
new file mode 100644
index 0000000000..d185adf49d
--- /dev/null
+++ b/core/fxge/dib/fx_dib_engine_unittest.cpp
@@ -0,0 +1,30 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <memory>
+
+#include "core/fpdfapi/fpdf_parser/include/cpdf_dictionary.h"
+#include "core/fpdfapi/fpdf_parser/include/cpdf_number.h"
+#include "core/fpdfapi/fpdf_parser/include/cpdf_stream.h"
+#include "core/fpdfapi/fpdf_render/render_int.h"
+#include "core/fxcrt/include/fx_memory.h"
+#include "core/fxge/dib/dib_int.h"
+#include "core/fxge/include/fx_dib.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+TEST(CStretchEngine, OverflowInCtor) {
+ FX_RECT clip_rect;
+ std::unique_ptr<CPDF_Dictionary, ReleaseDeleter<CPDF_Dictionary>> dict_obj(
+ new CPDF_Dictionary);
+ dict_obj->SetAt("Width", new CPDF_Number(71000));
+ dict_obj->SetAt("Height", new CPDF_Number(12500));
+ std::unique_ptr<CPDF_Stream, ReleaseDeleter<CPDF_Stream>> stream(
+ new CPDF_Stream(nullptr, 0, dict_obj.release()));
+ CPDF_DIBSource dib_source;
+ dib_source.Load(nullptr, stream.get(), nullptr, nullptr, nullptr, nullptr,
+ false, 0, false);
+ CStretchEngine engine(nullptr, FXDIB_8bppRgb, 500, 500, clip_rect,
+ &dib_source, 0);
+ EXPECT_EQ(FXDIB_INTERPOL, engine.m_Flags);
+}