This update for grub2 fixes the following issues: - Fix for CVE-2020-10713 - Fix for CVE-2020-14308 CVE-2020-14309, CVE-2020-14310, CVE-2020-14311 - Fix for CVE-2020-15706 - Fix for CVE-2020-15707 - Use overflow checking primitives where the arithmetic expression for buffer allocations may include unvalidated data - Use grub_calloc for overflow check and return NULL when it would occur - Use gcc-9 compiler for overflow check builtins - Backport gcc-9 build fixes