[Pdns-users] PowerDNS 2.9.7 released! Crash through misconfiguration!

[Steve Bromwich]

Hi,

I just installed 2.9.7 on a test machine and did a brain-dead cut and
paste config from another machine and found a bug (fortunately more of the
"admin screwed up" rather than "pdns fatally broken requiring an
immediate re-release" ;-):

Mar 20 16:28:26 quoth pdns[21547]: UDP server bound to 142.176.232.76:53
Mar 20 16:28:26 quoth pdns[21547]: TCP server bound to 142.176.232.76:53
Mar 20 16:28:26 quoth pdns[21547]: PowerDNS 2.9.7 (C) 2001-2003
PowerDNS.COM BV (Mar 20 2003, 13:23:48) starting up
Mar 20 16:28:26 quoth pdns[21547]: PowerDNS comes with ABSOLUTELY NO
WARRANTY. This is free software, and you are welcome to redistribute it
according to the terms of the GPL version 2.
Mar 20 16:28:26 quoth pdns[21547]: Set effective group id to 1003
Mar 20 16:28:26 quoth pdns[21547]: Set effective user id to 1003
Mar 20 16:28:26 quoth pdns[21547]: DNS Proxy launched, local port 44591,
remote 142.177.1.2:53
Mar 20 16:28:26 quoth pdns[21547]: Creating backend connection for TCP
Mar 20 16:28:26 quoth pdns[21547]: [bindbackend] Parsing 10 domain(s),
will report when done
Mar 20 16:28:26 quoth pdns[21547]: [bindbackend] Warning! Skipping 'hint'
zone '.'
Mar 20 16:28:26 quoth pdns[21547]: [bindbackend] parsing 'localhost' from
file '/etc/powerdns/domains/named.local'
Mar 20 16:28:26 quoth pdns[21547]: [bindbackend] parsing
'127.in-addr.arpa' from file '/etc/powerdns/domains/named.rev-local'
Mar 20 16:28:26 quoth pdns[21547]: [bindbackend] parsing
'232.176.142.in-addr.arpa' from file '/etc/powerdns/domains/named.rev-142.176'
Mar 20 16:28:26 quoth pdns[21547]: [bindbackend] parsing
'12.222.24.in-addr.arpa' from file '/etc/powerdns/domains/named.rev-24.222'
Mar 20 16:28:26 quoth pdns[21547]: [bindbackend] parsing 'impsolweb.ca'
from file '/etc/powerdns/domains/impsolweb.ca'
Mar 20 16:28:26 quoth pdns[21547]: [bindbackend] parsing 'impsolweb.com'
from file '/etc/powerdns/domains/impsolweb.com'
Mar 20 16:28:26 quoth pdns[21547]: [bindbackend] parsing
'impevolution.com' from file '/etc/powerdns/domains/impevolution.com'
Mar 20 16:28:26 quoth pdns[21547]: [bindbackend] parsing 'impsolutions.ca'
from file '/etc/powerdns/domains/impsolutions.ca'
Mar 20 16:28:26 quoth pdns[21547]: [bindbackend] parsing 'fop.ns.ca' from
file '/etc/powerdns/domains/fop.ns.ca'
Mar 20 16:28:26 quoth pdns[21547]: [bindbackend] Done parsing domains, 0
rejected, 9 new, 0 removed
Mar 20 16:28:26 quoth pdns[21547]: [bindbackend] Number of hash buckets:
193, number of entries: 58
Mar 20 16:28:26 quoth pdns[21551]: Fatal error in webserver: binding to
port 8765: Cannot assign requested address
Mar 20 16:28:26 quoth pdns[21553]: Master/slave communicator launching
Mar 20 16:28:26 quoth pdns[21553]: Got a signal 11, attempting to print
trace: 
Mar 20 16:28:26 quoth pdns[21553]: [0x80a9d3d]
Mar 20 16:28:26 quoth pdns[21553]: [0x8177218]
Mar 20 16:28:26 quoth pdns[21553]: [0x817f398]
Mar 20 16:28:26 quoth pdns[21553]: [0x80adfb5]
Mar 20 16:28:26 quoth pdns[21553]: [0x807a19e]
Mar 20 16:28:26 quoth pdns[21553]: [0x80c381c]
Mar 20 16:28:26 quoth pdns[21553]: [0x80d48a1]
Mar 20 16:28:26 quoth pdns[21553]: [0x8174aaa]
Mar 20 16:28:26 quoth pdns[21553]: [0x81b41aa]

pdns will keep looping over and over crashing with a sig11. Here's the
config:

module-dir=/usr/lib/powerdns
socket-dir=/var/run/
setuid=pdns
setgid=pdns
launch=bind,pipe
bind-config=/etc/powerdns/bind/named.conf
bind-check-interval=3600
pipe-command=/usr/local/scripts/pdnsbackend
pipe-regex=^lb.impsolweb.ca;(ANY|A)$
query-logging=off
allow-axfr-ips=24.222.12.2
allow-recursion=10.96.0.0/16
cache-ttl=1
config-dir=/etc/powerdns
default-soa-name=impsolweb.ca
disable-axfr=yes
disable-tcp=no
distributor-threads=20
pipe-timeout=5000
pipe-command=/usr/local/scripts/pdnsbackend
local-address=142.176.232.76
log-failed-updates=yes
loglevel=4
log-dns-details=no
master=yes
out-of-zone-additional-processing=no
recursor=142.177.1.2
slave=yes
soa-minimum-ttl=300
strict-rfc-axfrs=no
webserver=yes
webserver-address=142.176.232.74
webserver-password=somepassword
webserver-port=8765
wildcards=no

The bug here is that the server's IP is 142.176.232.76, but I forgot to
edit the webserver-address from .74 to .76. Once I updated that it all
worked fine. It'd be nice to check that IP addresses given that are to be
bound to exist on the machine before binding; if they don't exist, a
warning in the log would be preferable (for me) rather than halting
outright.

Cheers, Steve