commit 2d018126d75d8c1e342382a8a4801982b99c26e6
author Ray Essick <essick@google.com> Wed Nov 06 11:41:18 2019 -0800
committer Ray Essick <essick@google.com> Wed Nov 06 11:41:18 2019 -0800
tree 54e918f8b6fd2c1df68da42477d7e62327211152
parent 54ae7b773e2e1e1f9e373e8d803c39f2295ed2f0

allow/ignore overflow in ogg position calculations

Bug: 137530016
Test: poc in bug

media/extractors/ogg/OggExtractor.cpp

diff --git a/media/extractors/ogg/OggExtractor.cpp b/media/extractors/ogg/OggExtractor.cpp
index 4012ece..bfb2deb 100644
--- a/media/extractors/ogg/OggExtractor.cpp
+++ b/media/extractors/ogg/OggExtractor.cpp
@@ -635,7 +635,8 @@
             currentPageSamples -= mStartGranulePosition;
             AMediaFormat_setInt32(meta, AMEDIAFORMAT_KEY_VALID_SAMPLES, currentPageSamples);
         }
-        mCurGranulePosition = mCurrentPage.mGranulePosition - currentPageSamples;
+        (void) __builtin_sub_overflow(mCurrentPage.mGranulePosition, currentPageSamples,
+                                      &mCurGranulePosition);
     }
 
     int64_t timeUs = getTimeUsOfGranule(mCurGranulePosition);