As seen in this mariadb bug report:

https://mariadb.atlassian.net/browse/MDEV-8743

grastate.dat seems not to be opened with the O_CLOEXEC flag (close on exec). This means that child processes of mysqld have access to that file.

I see that O_CLOEXEC is used in other places in the code, might be some benefit to add it for grastate.dat too?

I quickly checked for grastate.dat, it seems to be opened with std::ifstream in gcomm::ViewState::read_file() which does not support that flag directly. Maybe do an open(..., O_CLOEXEC) first and the create an ifstream from the opened fd (if that's possible)?