And some are obviously correct... But others would require a lot more understanding of the code to be sure they're correct.
Someone should go through this with a keen eye to check the fixes are actually correct, and aren't just making the fuzzer stop alerting while leaving a more subtle vulnerability open.
Edit: Looks like GCC removed the warning because it was unreliable. Clang and MSVC seem to be in better shape. https://gcc.gnu.org/legacy-ml/gcc-help/2011-05/msg00360.html
That is an odd position when -Wstringop-overflow also highly depends on the optimizer (and will frequently generate false positives!) but not only remains in GCC but is enabled by default (even without any -Wall/-Wextra).
Things like this are why its pays to compile your project with as many compilers as possible (as well as static analysis tools).