In #385 we just skip errors related to /proc/sys but for those kinds of mounts it should be fine to permit mountpoint crossings if the mountpoint and the overmount root are the same filesystem (fsid) as that means that the overlay is the exact same contents just a different set of vfs flags -- which are safe.
Of course, this implies we will need it for openat2 as well.
In #385 we just skip errors related to
/proc/sysbut for those kinds of mounts it should be fine to permit mountpoint crossings if the mountpoint and the overmount root are the same filesystem (fsid) as that means that the overlay is the exact same contents just a different set of vfs flags -- which are safe.Of course, this implies we will need it for
openat2as well.