Function posix_directory_parent_secure

src/daemon/ipc.c:1379–1388

}

static bool posix_directory_parent_secure(int directory_fd) {
    struct stat status;
    if (directory_fd < 0 || fstat(directory_fd, &status) != 0 || !S_ISDIR(status.st_mode) ||
        !posix_directory_owner_trusted(status.st_uid) ||
        !cbm_macos_extended_acl_fd_is_deny_only(directory_fd)) {
        return false;
    }
    return (status.st_mode & 0022) == 0 ||
           (status.st_uid == (uid_t)0 && (status.st_mode & S_ISVTX) != 0);
}

/* Validate a path transition only through the two already-open directory
 * handles.  A group/other-writable parent is unsafe unless it is the standard