OSV-2020-1809 UNKNOWN WRITE in Imf_2_5::copyIntoFrameBuffer

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=25770 Crash type: UNKNOWN WRITE Crash state: Imf25::copyIntoFrameBuffer Imf25::LineBufferTask::execute IlmThread25::NullThreadPoolProvider::addTask...