remote fonts: Validate format on deserialized glyph.

R=mtklein@google.com, herb@google.com

Bug: 949000
Change-Id: Ib17635ea34db80987a1f2b3c0e6fcc33ab2b7a6b
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/206173
Commit-Queue: Khushal Sagar <khushalsagar@chromium.org>
Reviewed-by: Mike Klein <mtklein@google.com>
Reviewed-by: Herb Derby <herb@google.com>
Auto-Submit: Khushal Sagar <khushalsagar@chromium.org>
This commit is contained in:
Khushal 2019-04-05 12:32:02 -07:00 committed by Skia Commit-Bot
parent 8cc424806e
commit add8cf90b2
4 changed files with 21 additions and 15 deletions

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@ -40,6 +40,8 @@ struct SkMask {
uint32_t fRowBytes; uint32_t fRowBytes;
Format fFormat; Format fFormat;
static bool IsValidFormat(uint8_t format) { return format < kCountMaskFormats; }
/** Returns true if the mask is empty: i.e. it has an empty bounds. /** Returns true if the mask is empty: i.e. it has an empty bounds.
*/ */
bool isEmpty() const { return fBounds.isEmpty(); } bool isEmpty() const { return fBounds.isEmpty(); }

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@ -174,6 +174,10 @@ bool read_path(Deserializer* deserializer, SkGlyph* glyph, SkStrike* cache) {
auto* path = deserializer->read(pathSize, kPathAlignment); auto* path = deserializer->read(pathSize, kPathAlignment);
if (!path) return false; if (!path) return false;
// Don't overwrite the path if we already have one. We could have used a fallback if the
// glyph was missing earlier.
if (glyph->fPathData != nullptr) return true;
return cache->initializePath(glyph, path, pathSize); return cache->initializePath(glyph, path, pathSize);
} }
@ -486,8 +490,9 @@ void SkStrikeServer::SkGlyphCacheState::writePendingGlyphs(Serializer* serialize
for (const auto& glyphID : fPendingGlyphImages) { for (const auto& glyphID : fPendingGlyphImages) {
SkGlyph glyph{glyphID}; SkGlyph glyph{glyphID};
fContext->getMetrics(&glyph); fContext->getMetrics(&glyph);
writeGlyph(&glyph, serializer); SkASSERT(SkMask::IsValidFormat(glyph.fMaskFormat));
writeGlyph(&glyph, serializer);
auto imageSize = glyph.computeImageSize(); auto imageSize = glyph.computeImageSize();
if (imageSize == 0u) continue; if (imageSize == 0u) continue;
@ -503,6 +508,8 @@ void SkStrikeServer::SkGlyphCacheState::writePendingGlyphs(Serializer* serialize
for (const auto& glyphID : fPendingGlyphPaths) { for (const auto& glyphID : fPendingGlyphPaths) {
SkGlyph glyph{glyphID}; SkGlyph glyph{glyphID};
fContext->getMetrics(&glyph); fContext->getMetrics(&glyph);
SkASSERT(SkMask::IsValidFormat(glyph.fMaskFormat));
writeGlyph(&glyph, serializer); writeGlyph(&glyph, serializer);
writeGlyphPath(glyphID, serializer); writeGlyphPath(glyphID, serializer);
} }
@ -680,6 +687,8 @@ static bool readGlyph(SkTLazy<SkGlyph>& glyph, Deserializer* deserializer) {
if (!deserializer->read<int16_t>(&glyph->fLeft)) return false; if (!deserializer->read<int16_t>(&glyph->fLeft)) return false;
if (!deserializer->read<int8_t>(&glyph->fForceBW)) return false; if (!deserializer->read<int8_t>(&glyph->fForceBW)) return false;
if (!deserializer->read<uint8_t>(&glyph->fMaskFormat)) return false; if (!deserializer->read<uint8_t>(&glyph->fMaskFormat)) return false;
if (!SkMask::IsValidFormat(glyph->fMaskFormat)) return false;
return true; return true;
} }
@ -764,9 +773,14 @@ bool SkStrikeClient::readStrikeData(const volatile void* memory, size_t memorySi
auto imageSize = glyph->computeImageSize(); auto imageSize = glyph->computeImageSize();
if (imageSize == 0u) continue; if (imageSize == 0u) continue;
auto* image = deserializer.read(imageSize, allocatedGlyph->formatAlignment()); auto* image = deserializer.read(imageSize, glyph->formatAlignment());
if (!image) READ_FAILURE if (!image) READ_FAILURE
strike->initializeImage(image, imageSize, allocatedGlyph);
// Don't overwrite the image if we already have one. We could have used a fallback if
// the glyph was missing earlier.
if (allocatedGlyph->fImage == nullptr) {
strike->initializeImage(image, imageSize, allocatedGlyph);
}
} }
uint64_t glyphPathsCount = 0u; uint64_t glyphPathsCount = 0u;

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@ -142,9 +142,7 @@ const void* SkStrike::findImage(const SkGlyph& glyph) {
} }
void SkStrike::initializeImage(const volatile void* data, size_t size, SkGlyph* glyph) { void SkStrike::initializeImage(const volatile void* data, size_t size, SkGlyph* glyph) {
// Don't overwrite the image if we already have one. We could have used a fallback if the SkASSERT(!glyph->fImage);
// glyph was missing earlier.
if (glyph->fImage) return;
if (glyph->fWidth > 0 && glyph->fWidth < kMaxGlyphWidth) { if (glyph->fWidth > 0 && glyph->fWidth < kMaxGlyphWidth) {
size_t allocSize = glyph->allocImage(&fAlloc); size_t allocSize = glyph->allocImage(&fAlloc);
@ -180,9 +178,7 @@ const SkPath* SkStrike::findPath(const SkGlyph& glyph) {
} }
bool SkStrike::initializePath(SkGlyph* glyph, const volatile void* data, size_t size) { bool SkStrike::initializePath(SkGlyph* glyph, const volatile void* data, size_t size) {
// Don't overwrite the path if we already have one. We could have used a fallback if the SkASSERT(!glyph->fPathData);
// glyph was missing earlier.
if (glyph->fPathData) return true;
if (glyph->fWidth) { if (glyph->fWidth) {
SkGlyph::PathData* pathData = fAlloc.make<SkGlyph::PathData>(); SkGlyph::PathData* pathData = fAlloc.make<SkGlyph::PathData>();

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@ -950,12 +950,6 @@ DEF_TEST(SkRemoteGlyphCache_ReWriteGlyph, reporter) {
REPORTER_ASSERT(reporter, fallbackCache.get() != nullptr); REPORTER_ASSERT(reporter, fallbackCache.get() != nullptr);
auto glyph = fallbackCache->getRawGlyphByID(lostGlyphID); auto glyph = fallbackCache->getRawGlyphByID(lostGlyphID);
REPORTER_ASSERT(reporter, glyph->fMaskFormat == fakeMask); REPORTER_ASSERT(reporter, glyph->fMaskFormat == fakeMask);
// Try overriding the image, it should stay the same.
REPORTER_ASSERT(reporter,
memcmp(glyph->fImage, glyphImage, glyph->computeImageSize()) == 0);
const uint8_t newGlyphImage[] = {0, 0};
fallbackCache->initializeImage(newGlyphImage, glyph->computeImageSize(), glyph);
REPORTER_ASSERT(reporter, REPORTER_ASSERT(reporter,
memcmp(glyph->fImage, glyphImage, glyph->computeImageSize()) == 0); memcmp(glyph->fImage, glyphImage, glyph->computeImageSize()) == 0);
} }