bin/149363: tcsh cause situation when ssh connection closed

[napTu]

>Number:         149363
>Category:       bin
>Synopsis:       tcsh cause situation when ssh connection closed
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Aug 06 13:20:01 UTC 2010
>Closed-Date:
>Last-Modified:
>Originator:     napTu
>Release:        8.0
>Organization:
icenet
>Environment:
FreeBSD router5 8.0-STABLE FreeBSD 8.0-STABLE #1: Fri May  7 02:03:26 UTC 2010     root@:/buildscripts/frenzybuild/build/buildscripts/frenzybuild/src/sys/FRENZY  i386
>Description:
tcsh cause situation when after some work time, on any output,
message appears:
=============
router5:/etc@[15:44] # ./ngcarspd
50
11992000 bit/s
Connection to router5.icenet closed by remote host.
Connection to router5.icenet closed.
=============
ping is ok:
=============
icenet# ping 192.168.10.11
PING 192.168.10.11 (192.168.10.11): 56 data bytes
64 bytes from 192.168.10.11: icmp_seq=0 ttl=64 time=0.270 ms
64 bytes from 192.168.10.11: icmp_seq=1 ttl=64 time=2.156 ms
^C
--- 192.168.10.11 ping statistics ---
2 packets transmitted, 2 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 0.270/1.213/2.156/0.943 ms
=============
again connect request give:
=============
icenet# ssh router5
Connection closed by 192.168.10.11
=============
and again:
=============
icenet#
icenet# ssh router5
Last login: Fri Aug  6 10:30:59 2010 from hst.icenet
Copyright (c) 1980, 1983, 1986, 1988, 1990, 1991, 1993, 1994
        The Regents of the University of California.  All rights reserved.

Frenzy 1.2-standard 

router5:/root@[15:45] #
=============
- normal login
=============
messages show:
=============
Aug  6 15:44:42 router5 sshd[61168]: fatal: Write failed: Cannot allocate memory
Aug  6 15:44:47 router5 sshd[86877]: fatal: Write failed: Cannot allocate memory
=============

After some time I can't connect more to the host. On local shell work only combinations ALT+F1-F4,F12. Network subsystem continue processing traffic.

If I switch shell to /bin/sh, then this problem not appear.
Shell tcsh is configured in colorized format with time output and each hour DING: 
router5:/root@[15:45] # 

>How-To-Repeat:
Shell tcsh is configured in colorized format with time output and each hour DING: 
router5:/root@[15:45] #
>Fix:
switch shell to /bin/sh

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