SUMMARY: inetd/discard bug in 4.0d

From: John P . Speno <speno_at_isc.upenn.edu>
Date: Wed, 20 May 1998 15:37:21 -0400

This is a SUMMARY w/o a question.

There is a bug in the behavior of inetd in
Digital UNIX 4.0D (only tested with patch kit 1 installed).

To see this bug in action, telnet to the system's discard port
(tcp port 9), then close the connection from telnet (C-[ quit
RETURN).

Then notice that there is an inetd process spinning away, chewing
up CPU.

Repeat until you get bored.

I've reported this to Digital, and they have a workaround until
a real solution is available.

The workaround is to turn off tcp_keepalive.

        sysconfig -r inet tcp_keepalive_default=1

[of course you can set that in your /etc/sysconfigtab]

Or, you can disable discard in your /etc/inetd.conf file and restart
inetd. Unless you need it for something, I suggest you do this on all
of your systems. Turn off time, daytime, echo, and chargen while you
are at it. Why stop there? Don't run inetd at all. :-)

Take care.
Received on Wed May 20 1998 - 21:39:17 NZST

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