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@@ -0,0 +1,88 @@
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+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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+From: Cheng Zhao <[email protected]>
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+Date: Thu, 4 Oct 2018 14:57:02 -0700
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+Subject: fix: drop SkTextBlobs with > 2M glyphs
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+
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+[1080481] [Medium] [CVE-2020-6523]: Security: Skia: Integer Overflow in GrTextBlob::Make
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+Backport https://skia.googlesource.com/skia.git/+/8d2ebfffaf6ece9a7e9839dca2d7907f241c3460
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+
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+diff --git a/src/core/SkCanvas.cpp b/src/core/SkCanvas.cpp
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+index 31dfff18337c260c5905f1e1843a1cc27ebead5b..0e145b998f81be223cc7256ca402cbb8d384f7f5 100644
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+--- a/src/core/SkCanvas.cpp
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++++ b/src/core/SkCanvas.cpp
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+@@ -2654,6 +2654,19 @@ void SkCanvas::drawTextBlob(const SkTextBlob* blob, SkScalar x, SkScalar y,
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+ TRACE_EVENT0("skia", TRACE_FUNC);
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+ RETURN_ON_NULL(blob);
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+ RETURN_ON_FALSE(blob->bounds().makeOffset(x, y).isFinite());
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++
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++ // Overflow if more than 2^21 glyphs stopping a buffer overflow latter in the stack.
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++ // See chromium:1080481
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++ // TODO: can consider unrolling a few at a time if this limit becomes a problem.
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++ int totalGlyphCount = 0;
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++ constexpr int kMaxGlyphCount = 1 << 21;
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++ SkTextBlob::Iter i(*blob);
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++ SkTextBlob::Iter::Run r;
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++ while (i.next(&r)) {
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++ int glyphsLeft = kMaxGlyphCount - totalGlyphCount;
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++ RETURN_ON_FALSE(r.fGlyphCount <= glyphsLeft);
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++ totalGlyphCount += r.fGlyphCount;
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++ }
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+ this->onDrawTextBlob(blob, x, y, paint);
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+ }
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+
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+diff --git a/tests/TextBlobCacheTest.cpp b/tests/TextBlobCacheTest.cpp
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+index 536b2c1273eeef0eac0e2018d5d438687832203d..c0cdcfebdd96d210112835fee0ae63d69312105b 100644
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+--- a/tests/TextBlobCacheTest.cpp
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++++ b/tests/TextBlobCacheTest.cpp
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+@@ -229,6 +229,51 @@ static sk_sp<SkTextBlob> make_blob() {
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+ return builder.make();
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+ }
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+
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++// Turned off to pass on android and ios devices, which were running out of memory..
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++#if 0
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++static sk_sp<SkTextBlob> make_large_blob() {
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++ auto tf = SkTypeface::MakeFromName("Roboto2-Regular", SkFontStyle());
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++ SkFont font;
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++ font.setTypeface(tf);
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++ font.setSubpixel(false);
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++ font.setEdging(SkFont::Edging::kAlias);
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++ font.setSize(24);
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++
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++ const int mallocSize = 0x3c3c3bd; // x86 size
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++ std::unique_ptr<char[]> text{new char[mallocSize + 1]};
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++ if (text == nullptr) {
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++ return nullptr;
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++ }
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++ for (int i = 0; i < mallocSize; i++) {
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++ text[i] = 'x';
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++ }
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++ text[mallocSize] = 0;
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++
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++ static const int maxGlyphLen = mallocSize;
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++ std::unique_ptr<SkGlyphID[]> glyphs{new SkGlyphID[maxGlyphLen]};
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++ int glyphCount =
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++ font.textToGlyphs(
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++ text.get(), mallocSize, SkTextEncoding::kUTF8, glyphs.get(), maxGlyphLen);
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++ SkTextBlobBuilder builder;
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++ const auto& runBuffer = builder.allocRun(font, glyphCount, 0, 0);
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++ for (int i = 0; i < glyphCount; i++) {
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++ runBuffer.glyphs[i] = glyphs[i];
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++ }
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++ return builder.make();
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++}
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++
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++DEF_GPUTEST_FOR_RENDERING_CONTEXTS(TextBlobIntegerOverflowTest, reporter, ctxInfo) {
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++ auto grContext = ctxInfo.grContext();
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++ const SkImageInfo info =
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++ SkImageInfo::Make(kScreenDim, kScreenDim, kN32_SkColorType, kPremul_SkAlphaType);
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++ auto surface = SkSurface::MakeRenderTarget(grContext, SkBudgeted::kNo, info);
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++
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++ auto blob = make_large_blob();
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++ int y = 40;
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++ SkBitmap base = draw_blob(blob.get(), surface.get(), {40, y + 0.0f});
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++}
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++#endif
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++
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+ static const bool kDumpPngs = true;
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+ // dump pngs needs a "good" and a "bad" directory to put the results in. This allows the use of the
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+ // skdiff tool to visualize the differences.
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