CVE-2020-15900: Ghostscript zbitshift integer overflow via off-by-one shift range check

CVE-2020-15900 — rsearch post-string size off-by-one in Ghostscript 9.52

Ghostscript CVE-2020-15900: Integer Overflow in PostScript Calculator bitshift Operator

CVE-2020-15900: Integer overflow (signed left-shift UB) in Ghostscript bitshift PostScript operator

CVE-2020-15900: Ghostscript zbitshift signed integer overflow / UB in PostScript bitshift operator

CVE-2020-15900: Integer Underflow in Ghostscript rsearch Operator