misc/116722: ntpd core dumps if hostnames are not specifed with "-4" option

[Warren Block]

>Number:         116722
>Category:       misc
>Synopsis:       ntpd core dumps if hostnames are not specifed with "-4" option
>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 Sep 28 21:50:01 GMT 2007
>Closed-Date:
>Last-Modified:
>Originator:     Warren Block
>Release:        6.2-STABLE
>Organization:
>Environment:
FreeBSD speedy.wonkity.com 6.2-STABLE FreeBSD 6.2-STABLE #0: Fri Sep 28 13:51:02 MDT 2007     root at speedy.wonkity.com:/usr/obj/usr/src/sys/SPEEDY  i386
>Description:
Client system using ntpd has a kernel with only IPv4.  ntpd core dumps if hostnames are used without specific IPv4 notation.
>How-To-Repeat:
Compile/install kernel with INET but without INET6 kernel option.  In /etc/ntp.conf, use only server name:

# bad /etc/ntp.conf
server wonkity.com

This causes ntpd to core dump on startup:

speedy kernel: pid 1276 (ntpd), uid 0: exited on signal 11 (core dumped)


ntpd starts and runs normally if an IP address is used or if hostnames are preceded with the poorly-documented "-4" option:

# good /etc/ntp.conf
server 10.0.0.1
server -4 wonkity.com
>Fix:
Workaround: when running ntpd on clients with only IPv4, use IP addresses or precede hostnames with "-4" in /etc/ntp.conf.

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