[Bug 956655] Re: dnsmasq spams out thousands of queries

[Martin Pool]

So my machine had, every time I booted up, several instances:


mbp at joy% ps wwwax -o pid,ppid,cmd |grep dnsm
 1752     1 dnsmasq -u lxc-dnsmasq --strict-order --bind-interfaces --pid-file=/var/run/lxc/dnsmasq.pid --conf-file= --listen-address 10.0.3.1 --dhcp-range 10.0.3.2,10.0.3.254 --dhcp-lease-max=253 --dhcp-no-override --except-interface=lo --interface=lxcbr0
 1779     1 /usr/sbin/dnsmasq -u libvirt-dnsmasq --strict-order --bind-interfaces --pid-file=/var/run/libvirt/network/default.pid --conf-file= --except-interface lo --listen-address 192.168.122.1 --dhcp-range 192.168.122.2,192.168.122.254 --dhcp-leasefile=/var/lib/libvirt/dnsmasq/default.leases --dhcp-lease-max=253 --dhcp-no-override
 2780  1385 /usr/sbin/dnsmasq --no-resolv --keep-in-foreground --no-hosts --bind-interfaces --pid-file=/var/run/sendsigs.omit.d/network-manager.dnsmasq.pid --listen-address=127.0.0.1 --conf-file=/var/run/nm-dns-dnsmasq.conf --cache-size=0 --proxy-dnssec
 3242  3179 grep --color=auto dnsm
mbp at joy% ps 1385
  PID TTY      STAT   TIME COMMAND
 1385 ?        Ssl    0:00 NetworkManager

and it looks like 1752 and 2780 were furiously talking to each other,
and also flooding the network.  1752 was sending to 127.0.0.1:53 and
2780 received that message and echoed it back to 10.0.3.1 plus my
external DNS server:


2780  recvmsg(4, {msg_name(16)={sa_family=AF_INET, sin_port=htons(5269), sin_addr=inet_addr("127.0.0.1")}, msg_iov(1)=[{"\252\305\1\0\0\1\0\0\0\0\0\0\4talk\6google\3com\5fr
i"..., 4096}], msg_controllen=0, msg_flags=0}, 0) = 43
2780  sendto(12, "\270\25\1\0\0\1\0\0\0\0\0\0\4talk\6google\3com\5fri"..., 43, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.0.3.1")}, 16) = 43
2780  sendto(12, "\270\25\1\0\0\1\0\0\0\0\0\0\4talk\6google\3com\5fri"..., 43, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("192.168.178.1")}, 16) = 43
2780  sendto(12, "\270\25\1\0\0\1\0\0\0\0\0\0\4talk\6google\3com\5fri"..., 43, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("10.0.3.1")}, 16) = 43
2780  sendto(12, "\270\25\1\0\0\1\0\0\0\0\0\0\4talk\6google\3com\5fri"..., 43, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("192.168.178.1")}, 16) = 43
2780  select(19, [3 4 5 6 9 10 11 12 14 15 17 18], [], [], NULL) = 1 (in [4])


** Summary changed:

- dnsmasq spams out thousands of queries
+ libvirt dnsmasq causes runaway chain reaction

-- 
You received this bug notification because you are a member of Ubuntu
Server Team, which is subscribed to dnsmasq in Ubuntu.
https://bugs.launchpad.net/bugs/956655

Title:
  libvirt dnsmasq causes runaway chain reaction

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/dnsmasq/+bug/956655/+subscriptions