RESTRICT AUTOMERGE: Fix heap buffer overflow
Bug: b/118143775
Bug: oss-fuzz:11040
Test: I5fe66d06078f3bc674ceab4fbc8aae2ab67bfe1a
Because we're sampling, the offset ends up the same as the width. Back
up to the left enough to fit the bytes we will write.
Include SafetyNet logging from
https://skia-review.googlesource.com/c/skia/+/171227
Change-Id: Ie476a0191b66c2322446b9c0922f630d6e971645
Reviewed-on: https://skia-review.googlesource.com/c/164262
diff --git a/src/codec/SkSwizzler.cpp b/src/codec/SkSwizzler.cpp
index f88817f..ca82586 100644
--- a/src/codec/SkSwizzler.cpp
+++ b/src/codec/SkSwizzler.cpp
@@ -12,6 +12,10 @@
#include "SkSwizzler.h"
#include "SkTemplates.h"
+#ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
+ #include "SkAndroidFrameworkUtils.h"
+#endif
+
static void copy(void* dst, const uint8_t* src, int width, int bpp, int deltaSrc, int offset,
const SkPMColor ctable[]) {
// This function must not be called if we are sampling. If we are not
@@ -1186,6 +1190,18 @@
fSwizzleWidth = get_scaled_dimension(fSrcWidth, sampleX);
fAllocatedWidth = get_scaled_dimension(fDstWidth, sampleX);
+ if (fDstOffsetBytes > 0) {
+ const size_t dstSwizzleBytes = fSwizzleWidth * fDstBPP;
+ const size_t dstAllocatedBytes = fAllocatedWidth * fDstBPP;
+ if (fDstOffsetBytes + dstSwizzleBytes > dstAllocatedBytes) {
+#ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
+ SkAndroidFrameworkUtils::SafetyNetLog("118143775");
+#endif
+ SkASSERT(dstSwizzleBytes < dstAllocatedBytes);
+ fDstOffsetBytes = dstAllocatedBytes - dstSwizzleBytes;
+ }
+ }
+
// The optimized swizzler functions do not support sampling. Sampled swizzles
// are already fast because they skip pixels. We haven't seen a situation
// where speeding up sampling has a significant impact on total decode time.
