OSV-2020-2068 Heap-buffer-overflow in WelsDec::Update8x8RefIdx

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=26328 Crash type: Heap-buffer-overflow WRITE 1 Crash state: WelsDec::Update8x8RefIdx WelsDec::ParseInterBMotionInfoCabac WelsDec::WelsDecodeMbCabacBSliceBaseMode0...

OSV-2020-1258 Heap-use-after-free in WelsDec::MapColToList0

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=13457 Crash type: Heap-use-after-free READ 4 Crash state: WelsDec::MapColToList0 WelsDec::PredBDirectTemporal WelsDec::ParseInterBMotionInfoCabac...