Avoid integer overflow in SkIcoCodec and SkImageInfo

Original Commit Message:
"""
Avoid integer overflow in SkIcoCodec

Definitely good to avoid overflow here.

FWIW, this looks to be harmless for Android's current use.
They will just fail later on when trying to allocate the
bitmap.

BUG=skia:5857
"""

With the new test, ASAN also caught an integer overflow
bug in SkImageInfo.  Fix this as well.

CQ_INCLUDE_TRYBOTS=master.client.skia:Test-Ubuntu-Clang-GCE-CPU-AVX2-x86_64-Debug-ASAN;master.client.skia.android:Test-Android-Clang-AndroidOne-CPU-MT6582-arm-Debug-GN_Android

BUG=skia:5857

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=3568

Change-Id: I0d777a547850474ea6cea87e36efa05434e33635
Reviewed-on: https://skia-review.googlesource.com/3568
Reviewed-by: Kevin Lubick <kjlubick@google.com>

4 files changed, 18 insertions, 6 deletions

diff --git a/include/core/SkImageInfo.h b/include/core/SkImageInfo.h
index cf50acacae..8498f583fa 100644
--- a/include/core/SkImageInfo.h
+++ b/include/core/SkImageInfo.h
@@ -277,7 +277,11 @@ public:
     }
 
     size_t minRowBytes() const {
-        return (size_t)this->minRowBytes64();
+        uint64_t minRowBytes = this->minRowBytes64();
+        if (!sk_64_isS32(minRowBytes)) {
+            return 0;
+        }
+        return sk_64_asS32(minRowBytes);
     }
 
     size_t computeOffset(int x, int y, size_t rowBytes) const {
@@ -302,7 +306,7 @@ public:
         if (0 == fHeight) {
             return 0;
         }
-        return sk_64_mul(fHeight - 1, rowBytes) + fWidth * this->bytesPerPixel();
+        return sk_64_mul(fHeight - 1, rowBytes) + sk_64_mul(fWidth, this->bytesPerPixel());
     }
 
     size_t getSafeSize(size_t rowBytes) const {
diff --git a/resources/invalid_images/int_overflow.ico b/resources/invalid_images/int_overflow.ico
new file mode 100644
index 0000000000..ba675666b6
--- /dev/null
+++ b/resources/invalid_images/int_overflow.ico
diff --git a/src/codec/SkIcoCodec.cpp b/src/codec/SkIcoCodec.cpp
index 63b72c4039..d01904dc1b 100644
--- a/src/codec/SkIcoCodec.cpp
+++ b/src/codec/SkIcoCodec.cpp
@@ -157,11 +157,12 @@ SkCodec* SkIcoCodec::NewFromStream(SkStream* stream) {
     }
 
     // Use the largest codec as a "suggestion" for image info
-    uint32_t maxSize = 0;
-    uint32_t maxIndex = 0;
-    for (int32_t i = 0; i < codecs->count(); i++) {
+    size_t maxSize = 0;
+    int maxIndex = 0;
+    for (int i = 0; i < codecs->count(); i++) {
         SkImageInfo info = codecs->operator[](i)->getInfo();
-        uint32_t size = info.width() * info.height();
+        size_t size = info.getSafeSize(info.minRowBytes());
+
         if (size > maxSize) {
             maxSize = size;
             maxIndex = i;
diff --git a/tests/CodecTest.cpp b/tests/CodecTest.cpp
index 4d18c61860..a6058a9c35 100644
--- a/tests/CodecTest.cpp
+++ b/tests/CodecTest.cpp
@@ -1362,3 +1362,10 @@ DEF_TEST(Codec_rowsDecoded, r) {
     REPORTER_ASSERT(r, result == SkCodec::kIncompleteInput);
     REPORTER_ASSERT(r, rowsDecoded == 0);
 }
+
+DEF_TEST(Codec_IcoIntOverflow, r) {
+    // ASAN will complain if there is an issue.
+    SkBitmap bitmap;
+    const bool success = GetResourceAsBitmap("invalid_images/int_overflow.ico", &bitmap);
+    REPORTER_ASSERT(r, !success);
+}