OpenSSH -- Pre-authentication async signal safety issue

The FreeBSD Project reports:

    A signal handler in sshd(8) may call a logging function that is not async-
    signal-safe. The signal handler is invoked when a client does not
    authenticate within the LoginGraceTime seconds (120 by default).
    This signal handler executes in the context of the sshd(8)'s privileged
    code, which is not sandboxed and runs with full root privileges.

    This issue is another instance of the problem in CVE-2024-6387 addressed by
    FreeBSD-SA-24:04.openssh.  The faulty code in this case is from the
    integration of blacklistd in OpenSSH in FreeBSD.