OSV-2021-871 Heap-use-after-free in jxl::ImageBlender::PrepareBlending

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35293 Crash type: Heap-use-after-free READ 8 Crash state: jxl::ImageBlender::PrepareBlending jxl::FinalizeFrameDecoding jxl::FrameDecoder::Flush...

OSV-2021-786 Heap-buffer-overflow in jxl::PerformAlphaWeightedAdd

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=34518 Crash type: Heap-buffer-overflow WRITE Crash state: jxl::PerformAlphaWeightedAdd jxl::PerformBlending jxl::ImageBlender::RectBlender::DoBlending...