diff --git a/include/core/SkPicture.h b/include/core/SkPicture.h
index 1a5ecb3..f0e9e0e 100644
--- a/include/core/SkPicture.h
+++ b/include/core/SkPicture.h
@@ -174,6 +174,8 @@
     static const uint32_t     MIN_PICTURE_VERSION = 56;     // august 2017
     static const uint32_t CURRENT_PICTURE_VERSION = 62;
 
+    static_assert(MIN_PICTURE_VERSION <= 62, "Remove kFontAxes_bad from SkFontDescriptor.cpp");
+
     static bool IsValidPictInfo(const SkPictInfo& info);
     static sk_sp<SkPicture> Forwardport(const SkPictInfo&,
                                         const SkPictureData*,
diff --git a/include/core/SkStream.h b/include/core/SkStream.h
index 75fef12..2d9f9db 100644
--- a/include/core/SkStream.h
+++ b/include/core/SkStream.h
@@ -83,17 +83,22 @@
      */
     virtual bool isAtEnd() const = 0;
 
-    int8_t   readS8();
-    int16_t  readS16();
-    int32_t  readS32();
+    bool SK_WARN_UNUSED_RESULT readS8(int8_t*);
+    bool SK_WARN_UNUSED_RESULT readS16(int16_t*);
+    bool SK_WARN_UNUSED_RESULT readS32(int32_t*);
 
-    uint8_t  readU8() { return (uint8_t)this->readS8(); }
-    uint16_t readU16() { return (uint16_t)this->readS16(); }
-    uint32_t readU32() { return (uint32_t)this->readS32(); }
+    bool SK_WARN_UNUSED_RESULT readU8(uint8_t* i) { return this->readS8((int8_t*)i); }
+    bool SK_WARN_UNUSED_RESULT readU16(uint16_t* i) { return this->readS16((int16_t*)i); }
+    bool SK_WARN_UNUSED_RESULT readU32(uint32_t* i) { return this->readS32((int32_t*)i); }
 
-    bool     readBool() { return this->readU8() != 0; }
-    SkScalar readScalar();
-    size_t   readPackedUInt();
+    bool SK_WARN_UNUSED_RESULT readBool(bool* b) {
+        uint8_t i;
+        if (!this->readU8(&i)) { return false; }
+        *b = (i != 0);
+        return true;
+    }
+    bool SK_WARN_UNUSED_RESULT readScalar(SkScalar*);
+    bool SK_WARN_UNUSED_RESULT readPackedUInt(size_t*);
 
 //SkStreamRewindable
     /** Rewinds to the beginning of the stream. Returns true if the stream is known
@@ -247,16 +252,16 @@
 
     bool newline() { return this->write("\n", strlen("\n")); }
 
-    bool    writeDecAsText(int32_t);
-    bool    writeBigDecAsText(int64_t, int minDigits = 0);
-    bool    writeHexAsText(uint32_t, int minDigits = 0);
-    bool    writeScalarAsText(SkScalar);
+    bool writeDecAsText(int32_t);
+    bool writeBigDecAsText(int64_t, int minDigits = 0);
+    bool writeHexAsText(uint32_t, int minDigits = 0);
+    bool writeScalarAsText(SkScalar);
 
-    bool    writeBool(bool v) { return this->write8(v); }
-    bool    writeScalar(SkScalar);
-    bool    writePackedUInt(size_t);
+    bool writeBool(bool v) { return this->write8(v); }
+    bool writeScalar(SkScalar);
+    bool writePackedUInt(size_t);
 
-    bool    writeStream(SkStream* input, size_t length);
+    bool writeStream(SkStream* input, size_t length);
 
     /**
      * This returns the number of bytes in the stream required to store
diff --git a/src/core/SkFontDescriptor.cpp b/src/core/SkFontDescriptor.cpp
index 14b0318..ccc19eb 100644
--- a/src/core/SkFontDescriptor.cpp
+++ b/src/core/SkFontDescriptor.cpp
@@ -11,6 +11,8 @@
 #include "SkData.h"
 
 enum {
+    kInvalid        = 0x00,
+
     // these must match the sfnt 'name' enums
     kFontFamilyName = 0x01,
     kFullName       = 0x04,
@@ -18,40 +20,45 @@
 
     // These count backwards from 0xFF, so as not to collide with the SFNT
     // defines for names in its 'name' table.
-    kFontAxes       = 0xFC,
+    kFontAxes       = 0xFB,
+    kFontAxes_bad   = 0xFC, // Broken negative axes, remove when MIN_PICTURE_VERSION > 62.
     kFontIndex      = 0xFD,
     kSentinel       = 0xFF,
 };
 
 SkFontDescriptor::SkFontDescriptor() { }
 
-static void read_string(SkStream* stream, SkString* string) {
-    const uint32_t length = SkToU32(stream->readPackedUInt());
+static bool SK_WARN_UNUSED_RESULT read_string(SkStream* stream, SkString* string) {
+    size_t length;
+    if (!stream->readPackedUInt(&length)) { return false; }
     if (length > 0) {
         string->resize(length);
-        stream->read(string->writable_str(), length);
+        if (stream->read(string->writable_str(), length) != length) { return false; }
     }
+    return true;
 }
 
-static void write_string(SkWStream* stream, const SkString& string, uint32_t id) {
-    if (!string.isEmpty()) {
-        stream->writePackedUInt(id);
-        stream->writePackedUInt(string.size());
-        stream->write(string.c_str(), string.size());
-    }
+static bool write_string(SkWStream* stream, const SkString& string, uint32_t id) {
+    if (string.isEmpty()) { return true; }
+    return stream->writePackedUInt(id) &&
+           stream->writePackedUInt(string.size()) &&
+           stream->write(string.c_str(), string.size());
 }
 
-static size_t read_uint(SkStream* stream) {
-    return stream->readPackedUInt();
+static bool write_uint(SkWStream* stream, size_t n, uint32_t id) {
+    return stream->writePackedUInt(id) &&
+           stream->writePackedUInt(n);
 }
 
-static void write_uint(SkWStream* stream, size_t n, uint32_t id) {
-    stream->writePackedUInt(id);
-    stream->writePackedUInt(n);
+static size_t SK_WARN_UNUSED_RESULT read_id(SkStream* stream) {
+    size_t i;
+    if (!stream->readPackedUInt(&i)) { return kInvalid; }
+    return i;
 }
 
 bool SkFontDescriptor::Deserialize(SkStream* stream, SkFontDescriptor* result) {
-    size_t styleBits = stream->readPackedUInt();
+    size_t styleBits;
+    if (!stream->readPackedUInt(&styleBits)) { return false; }
     result->fStyle = SkFontStyle((styleBits >> 16) & 0xFFFF,
                                  (styleBits >> 8 ) & 0xFF,
                                  static_cast<SkFontStyle::Slant>(styleBits & 0xFF));
@@ -59,26 +66,35 @@
     SkAutoSTMalloc<4, SkFixed> axis;
     size_t axisCount = 0;
     size_t index = 0;
-    for (size_t id; (id = stream->readPackedUInt()) != kSentinel;) {
+    for (size_t id; (id = read_id(stream)) != kSentinel;) {
         switch (id) {
             case kFontFamilyName:
-                read_string(stream, &result->fFamilyName);
+                if (!read_string(stream, &result->fFamilyName)) { return false; }
                 break;
             case kFullName:
-                read_string(stream, &result->fFullName);
+                if (!read_string(stream, &result->fFullName)) { return false; }
                 break;
             case kPostscriptName:
-                read_string(stream, &result->fPostscriptName);
+                if (!read_string(stream, &result->fPostscriptName)) { return false; }
                 break;
             case kFontAxes:
-                axisCount = read_uint(stream);
+                if (!stream->readPackedUInt(&axisCount)) { return false; }
                 axis.reset(axisCount);
                 for (size_t i = 0; i < axisCount; ++i) {
-                    axis[i] = read_uint(stream);
+                    if (!stream->readS32(&axis[i])) { return false; }
+                }
+                break;
+            case kFontAxes_bad:
+                if (!stream->readPackedUInt(&axisCount)) { return false; }
+                axis.reset(axisCount);
+                for (size_t i = 0; i < axisCount; ++i) {
+                    size_t packedAxis;
+                    if (!stream->readPackedUInt(&packedAxis)) { return false; }
+                    axis[i] = packedAxis;
                 }
                 break;
             case kFontIndex:
-                index = read_uint(stream);
+                if (!stream->readPackedUInt(&index)) { return false; }
                 break;
             default:
                 SkDEBUGFAIL("Unknown id used by a font descriptor");
@@ -86,16 +102,16 @@
         }
     }
 
-    size_t length = stream->readPackedUInt();
+    size_t length;
+    if (!stream->readPackedUInt(&length)) { return false; }
     if (length > 0) {
         sk_sp<SkData> data(SkData::MakeUninitialized(length));
-        if (stream->read(data->writable_data(), length) == length) {
-            result->fFontData = skstd::make_unique<SkFontData>(
-                                   SkMemoryStream::Make(std::move(data)), index, axis, axisCount);
-        } else {
+        if (stream->read(data->writable_data(), length) != length) {
             SkDEBUGFAIL("Could not read font data");
             return false;
         }
+        result->fFontData = skstd::make_unique<SkFontData>(
+            SkMemoryStream::Make(std::move(data)), index, axis, axisCount);
     }
     return true;
 }
@@ -114,7 +130,7 @@
         if (fFontData->getAxisCount()) {
             write_uint(stream, fFontData->getAxisCount(), kFontAxes);
             for (int i = 0; i < fFontData->getAxisCount(); ++i) {
-                stream->writePackedUInt(fFontData->getAxis()[i]);
+                stream->write32(fFontData->getAxis()[i]);
             }
         }
     }
diff --git a/src/core/SkPicture.cpp b/src/core/SkPicture.cpp
index 85b22ac..5993e49 100644
--- a/src/core/SkPicture.cpp
+++ b/src/core/SkPicture.cpp
@@ -80,24 +80,25 @@
 
     SkPictInfo info;
     SkASSERT(sizeof(kMagic) == sizeof(info.fMagic));
-    if (!stream->read(&info.fMagic, sizeof(kMagic))) {
+    if (stream->read(&info.fMagic, sizeof(kMagic)) != sizeof(kMagic)) {
         return false;
     }
 
-    info.setVersion(         stream->readU32());
-    info.fCullRect.fLeft   = stream->readScalar();
-    info.fCullRect.fTop    = stream->readScalar();
-    info.fCullRect.fRight  = stream->readScalar();
-    info.fCullRect.fBottom = stream->readScalar();
+    uint32_t version;
+    if (!stream->readU32(&version)) { return false; }
+    info.setVersion(version);
+    if (!stream->readScalar(&info.fCullRect.fLeft  )) { return false; }
+    if (!stream->readScalar(&info.fCullRect.fTop   )) { return false; }
+    if (!stream->readScalar(&info.fCullRect.fRight )) { return false; }
+    if (!stream->readScalar(&info.fCullRect.fBottom)) { return false; }
     if (info.getVersion() < SkReadBuffer::kRemoveHeaderFlags_Version) {
-        (void)stream->readU32();    // used to be flags
+        if (!stream->readU32(nullptr)) { return false; }
     }
 
-    if (IsValidPictInfo(info)) {
-        if (pInfo) { *pInfo = info; }
-        return true;
-    }
-    return false;
+    if (!IsValidPictInfo(info)) { return false; }
+
+    if (pInfo) { *pInfo = info; }
+    return true;
 }
 bool SkPicture_StreamIsSKP(SkStream* stream, SkPictInfo* pInfo) {
     return SkPicture::StreamIsSKP(stream, pInfo);
@@ -171,15 +172,17 @@
         procs = *procsPtr;
     }
 
-    switch (stream->readU8()) {
+    uint8_t trailingStreamByteAfterPictInfo;
+    if (!stream->readU8(&trailingStreamByteAfterPictInfo)) { return nullptr; }
+    switch (trailingStreamByteAfterPictInfo) {
         case kPictureData_TrailingStreamByteAfterPictInfo: {
             std::unique_ptr<SkPictureData> data(
                     SkPictureData::CreateFromStream(stream, info, procs, typefaces));
             return Forwardport(info, data.get(), nullptr);
         }
         case kCustom_TrailingStreamByteAfterPictInfo: {
-            int32_t ssize = stream->readS32();
-            if (ssize >= 0 || !procs.fPictureProc) {
+            int32_t ssize;
+            if (!stream->readS32(&ssize) || ssize >= 0 || !procs.fPictureProc) {
                 return nullptr;
             }
             size_t size = sk_negate_to_size_t(ssize);
diff --git a/src/core/SkPictureData.cpp b/src/core/SkPictureData.cpp
index efd4183..6be36dd 100644
--- a/src/core/SkPictureData.cpp
+++ b/src/core/SkPictureData.cpp
@@ -276,11 +276,12 @@
             break;
         case SK_PICT_FACTORY_TAG: {
             SkASSERT(!haveBuffer);
-            size = stream->readU32();
+            if (!stream->readU32(&size)) { return false; }
             fFactoryPlayback = skstd::make_unique<SkFactoryPlayback>(size);
             for (size_t i = 0; i < size; i++) {
                 SkString str;
-                const size_t len = stream->readPackedUInt();
+                size_t len;
+                if (!stream->readPackedUInt(&len)) { return false; }
                 str.resize(len);
                 if (stream->read(str.writable_str(), len) != len) {
                     return false;
@@ -480,12 +481,14 @@
                                 const SkDeserialProcs& procs,
                                 SkTypefacePlayback* topLevelTFPlayback) {
     for (;;) {
-        uint32_t tag = stream->readU32();
+        uint32_t tag;
+        if (!stream->readU32(&tag)) { return false; }
         if (SK_PICT_EOF_TAG == tag) {
             break;
         }
 
-        uint32_t size = stream->readU32();
+        uint32_t size;
+        if (!stream->readU32(&size)) { return false; }
         if (!this->parseStreamTag(stream, tag, size, procs, topLevelTFPlayback)) {
             return false; // we're invalid
         }
diff --git a/src/core/SkStream.cpp b/src/core/SkStream.cpp
index dfdc257..57fd7f5 100644
--- a/src/core/SkStream.cpp
+++ b/src/core/SkStream.cpp
@@ -20,50 +20,43 @@
 
 ///////////////////////////////////////////////////////////////////////////////
 
-int8_t SkStream::readS8() {
-    int8_t value;
-    SkDEBUGCODE(size_t len =) this->read(&value, 1);
-    SkASSERT(1 == len);
-    return value;
+bool SkStream::readS8(int8_t* i) {
+    return this->read(i, sizeof(*i)) == sizeof(*i);
 }
 
-int16_t SkStream::readS16() {
-    int16_t value;
-    SkDEBUGCODE(size_t len =) this->read(&value, 2);
-    SkASSERT(2 == len);
-    return value;
+bool SkStream::readS16(int16_t* i) {
+    return this->read(i, sizeof(*i)) == sizeof(*i);
 }
 
-int32_t SkStream::readS32() {
-    int32_t value;
-    SkDEBUGCODE(size_t len =) this->read(&value, 4);
-    SkASSERT(4 == len);
-    return value;
+bool SkStream::readS32(int32_t* i) {
+    return this->read(i, sizeof(*i)) == sizeof(*i);
 }
 
-SkScalar SkStream::readScalar() {
-    SkScalar value;
-    SkDEBUGCODE(size_t len =) this->read(&value, sizeof(SkScalar));
-    SkASSERT(sizeof(SkScalar) == len);
-    return value;
+bool SkStream::readScalar(SkScalar* i) {
+    return this->read(i, sizeof(*i)) == sizeof(*i);
 }
 
 #define SK_MAX_BYTE_FOR_U8          0xFD
 #define SK_BYTE_SENTINEL_FOR_U16    0xFE
 #define SK_BYTE_SENTINEL_FOR_U32    0xFF
 
-size_t SkStream::readPackedUInt() {
+bool SkStream::readPackedUInt(size_t* i) {
     uint8_t byte;
     if (!this->read(&byte, 1)) {
-        return 0;
+        return false;
     }
     if (SK_BYTE_SENTINEL_FOR_U16 == byte) {
-        return this->readU16();
+        uint16_t i16;
+        if (!this->readU16(&i16)) { return false; }
+        *i = i16;
     } else if (SK_BYTE_SENTINEL_FOR_U32 == byte) {
-        return this->readU32();
+        uint32_t i32;
+        if (!this->readU32(&i32)) { return false; }
+        *i = i32;
     } else {
-        return byte;
+        *i = byte;
     }
+    return true;
 }
 
 //////////////////////////////////////////////////////////////////////////////////////
diff --git a/src/utils/SkMultiPictureDocument.cpp b/src/utils/SkMultiPictureDocument.cpp
index b09db06..493e6d4 100644
--- a/src/utils/SkMultiPictureDocument.cpp
+++ b/src/utils/SkMultiPictureDocument.cpp
@@ -110,16 +110,16 @@
         stream = nullptr;
         return 0;
     }
-    uint32_t versionNumber = stream->readU32();
-    if (versionNumber != kVersion) {
+    uint32_t versionNumber;
+    if (!stream->readU32(&versionNumber) || versionNumber != kVersion) {
         return 0;
     }
-    uint32_t pageCount = stream->readU32();
-    if (pageCount > INT_MAX) {
+    uint32_t pageCount;
+    if (!stream->readU32(&pageCount) || pageCount > INT_MAX) {
         return 0;
     }
     // leave stream position right here.
-    return (int)pageCount;
+    return SkTo<int>(pageCount);
 }
 
 bool SkMultiPictureDocumentReadPageSizes(SkStreamSeekable* stream,
diff --git a/tests/StreamTest.cpp b/tests/StreamTest.cpp
index 49810ae..7cf8d92 100644
--- a/tests/StreamTest.cpp
+++ b/tests/StreamTest.cpp
@@ -159,9 +159,12 @@
 
     std::unique_ptr<SkStreamAsset> rstream(wstream.detachAsStream());
     for (i = 0; i < SK_ARRAY_COUNT(sizes); ++i) {
-        size_t n = rstream->readPackedUInt();
+        size_t n;
+        if (!rstream->readPackedUInt(&n)) {
+            ERRORF(reporter, "[%d] sizes:%x could not be read\n", i, sizes[i]);
+        }
         if (sizes[i] != n) {
-            ERRORF(reporter, "sizes:%x != n:%x\n", i, sizes[i], n);
+            ERRORF(reporter, "[%d] sizes:%x != n:%x\n", i, sizes[i], n);
         }
     }
 }
diff --git a/tests/TypefaceTest.cpp b/tests/TypefaceTest.cpp
index 34fa357..fcef366 100644
--- a/tests/TypefaceTest.cpp
+++ b/tests/TypefaceTest.cpp
@@ -8,6 +8,7 @@
 #include "SkAdvancedTypefaceMetrics.h"
 #include "SkData.h"
 #include "SkFixed.h"
+#include "SkFontDescriptor.h"
 #include "SkFontMgr.h"
 #include "SkMakeUnique.h"
 #include "SkOTTable_OS_2.h"
@@ -109,6 +110,30 @@
     REPORTER_ASSERT(reporter, typeface2);
 }
 
+DEF_TEST(FontDescriptorNegativeVariationSerialize, reporter) {
+    SkFontDescriptor desc;
+    SkFixed axis = -SK_Fixed1;
+    auto font = skstd::make_unique<SkMemoryStream>("a", 1, false);
+    desc.setFontData(skstd::make_unique<SkFontData>(std::move(font), 0, &axis, 1));
+
+    SkDynamicMemoryWStream stream;
+    desc.serialize(&stream);
+    SkFontDescriptor descD;
+    SkFontDescriptor::Deserialize(stream.detachAsStream().get(), &descD);
+    std::unique_ptr<SkFontData> fontData = descD.detachFontData();
+    if (!fontData) {
+        REPORT_FAILURE(reporter, "fontData", SkString());
+        return;
+    }
+
+    if (fontData->getAxisCount() != 1) {
+        REPORT_FAILURE(reporter, "fontData->getAxisCount() != 1", SkString());
+        return;
+    }
+
+    REPORTER_ASSERT(reporter, fontData->getAxis()[0] == -SK_Fixed1);
+};
+
 DEF_TEST(TypefaceAxes, reporter) {
     std::unique_ptr<SkStreamAsset> distortable(GetResourceAsStream("fonts/Distortable.ttf"));
     if (!distortable) {
diff --git a/tools/skpinfo.cpp b/tools/skpinfo.cpp
index 865492d..93834bb 100644
--- a/tools/skpinfo.cpp
+++ b/tools/skpinfo.cpp
@@ -65,7 +65,9 @@
                  info.fCullRect.fRight, info.fCullRect.fBottom);
     }
 
-    if (!stream.readBool()) {
+    bool hasData;
+    if (!stream.readBool(&hasData)) { return kTruncatedFile; }
+    if (!hasData) {
         // If we read true there's a picture playback object flattened
         // in the file; if false, there isn't a playback, so we're done
         // reading the file.
@@ -73,12 +75,14 @@
     }
 
     for (;;) {
-        uint32_t tag = stream.readU32();
+        uint32_t tag;
+        if (!stream.readU32(&tag)) { return kTruncatedFile; }
         if (SK_PICT_EOF_TAG == tag) {
             break;
         }
 
-        uint32_t chunkSize = stream.readU32();
+        uint32_t chunkSize;
+        if (!stream.readU32(&chunkSize)) { return kTruncatedFile; }
         size_t curPos = stream.getPosition();
 
         // "move" doesn't error out when seeking beyond the end of file