[Pdns-dev] segfault in recursor

[Sten Spans]

A simple misconfiguration revealed a segfault in the recursor.

root at ford:~# uname -a
Linux ford 2.6.15-26-amd64-server #1 SMP Thu Aug 3 03:32:26 UTC 2006 x86_64 GNU/Linux
root at ford:~# grep 127 /etc/powerdns/recursor.conf
allow-from=127.0.0.0/8, 192.168.0.0/16, ::1/128, fe80::/10
forward-zones=e.f.f.0.0.8.9.0.1.0.0.2.ip6.arpa=127.0.0.1
local-address=127.0.0.1,192.168.127.53,::1,2001:980:ffe:d::53

( aka, the resolver is talking to itself for an ipv6 reverse zone )

while true; do
 	dig -x 2001:980:ffe:3:2e0:81ff:fe2f:bb6a; 
done

this will lead to

kernel: [ 9906.383130] pdns_recursor[19101]: segfault at 0000000000676000 rip 000000000045af26 rsp 00000000006213e0 error 6
kernel: [10546.226961] pdns_recursor[24474]: segfault at 0000000000667000 rip 000000000045af20 rsp 00000000006215a0 error 4

It's reasonably easy to hit with a freshly restarted daemon.

-- 
Sten Spans

"There is a crack in everything, that's how the light gets in."
Leonard Cohen - Anthem