OSV-2020-913 Heap-buffer-overflow in sas_read4

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=12576 Crash type: Heap-buffer-overflow READ 4 Crash state: sasread4 sas7bdatparsepagepass1 sas7bdatparsemetapagespass1...