inetd fd leak?

[Doug Graham]

Cathey, Jim wrote:
>> Let's try to simplify it. Try some (or all) of these:
>>     
>
> Wilco.
>
>   
>> * Run inetd with the same config on your own x?86 desktop.
>>     
>
> That would be hard.  Not impossible, but hard.  (Not using
> busybox at all there, is my development system and don't
> want to screw it up.)  Might do that a bit later.
>
>   
I can reproduce this in UML.  My image is Fedora Core 5 with glibc-2.4-11
installed, and I built busybox 1.3.2 against glibc (not uClibc).  The 
leak appears
to be related to syslog.  For example, descriptor 6 was leaked, and 
strace shows
only these operations on that descriptor:

socket(PF_FILE, SOCK_DGRAM, 0)          = 6
fcntl64(6, F_SETFD, FD_CLOEXEC)         = 0
connect(6, {sa_family=AF_FILE, path="/dev/log"}, 110) = 0
send(6, "<27>Sep  3 17:49:45 inetd[1938]:"..., 75, MSG_NOSIGNAL) = 75

After another run of bury.sh, the same thing happens on descriptor 7 
(without 6
being closed first).  The message being logged is this one:

Sep  3 17:49:45 uml0 inetd[1938]: telnet/tcp: too many connections, pausing

This is so totally weird that I figured it had to have something to do with
vfork (just because vfork is so totally weird itself).  Replacing the 
vfork in
inetd.c with a fork instead does fix my leak.

--Doug.