bin/123065: inetd takes 100% cpu

[Tim Hogard]

>Number:         123065
>Category:       bin
>Synopsis:       inetd takes 100% cpu
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Apr 25 04:00:06 UTC 2008
>Closed-Date:
>Last-Modified:
>Originator:     Tim Hogard
>Release:        6.3 Stable
>Organization:
>Environment:
FreeBSD t0.abnormal.com 6.3-STABLE FreeBSD 6.3-STABLE #5: Mon Apr  7 11:00:07 UTC 2008     thogard at t0.abnormal.com:/usr/obj/usr/src/sys/TIM  amd64


>Description:
I'm running inetd from init by a config line in /etc/ttys as an attempt to get telnet access to a remote server  that likes to reboot into single user mode (i.e. the whole remote console problem)

This solution works however inetd to wants to take all the CPU after this starts and I suspect that is a result of some bug that might have larger implications.

in /etc/ttys:

none    "/usr/sbin/inetd -d -a 64.27.26.118 -p /tmp/foo2.pid /etc/inetd.single.conf" unknown on secure

Then in /etc/inetd.single.conf:
telnet    stream  tcp     nowait  root    /usr/libexec/telnetd    telnetd


>How-To-Repeat:
1) add below "console" in /etc/ttys
none    "/usr/sbin/inetd -d -p /tmp/foo2.pid /etc/inetd.single.conf" unknown on secure


2) then create /etc/inetd.single.conf
telnet    stream  tcp     nowait  root    /usr/libexec/telnetd    telnetd

3) tell init to look at /etc/ttys again:
# init q

4) from some other server
$ telnet host 
Login as a general user, then log out

5) Use top or ps to see inetd is taking 100% of the CPU

>Fix:
A fix to the problem my be a adding a "don't go in background" flag for inetd but this could just by a symptom of a different problem.

>Release-Note:
>Audit-Trail:
>Unformatted: