crash due to assertion failure on busy VM host

[Paul Collins]

Version: 1:4.2.8p4+dfsg-3ubuntu5.9

We've observed the following crash on an Ubuntu 16.04 s390x nova-compute host, apparently related to the VMs network interfaces coming and going:

Nov 11 01:40:34 s0lp3 ntpd[2426]: Listen normally on 542170 qvo8dd4fc29-b8 [fe80::2c99:58ff:fefa:b081%616530]:123
Nov 11 01:40:34 s0lp3 ntpd[2426]: Listen normally on 542171 qvb8dd4fc29-b8 [fe80::b809:4ff:fefc:1b17%616531]:123
Nov 11 01:40:34 s0lp3 ntpd[2426]: Listen normally on 542172 tap3ca379f2-d1 [fe80::fc16:3eff:fe6e:5ef7%616532]:123
Nov 11 01:40:34 s0lp3 ntpd[2426]: Listen normally on 542173 tap8dd4fc29-b8 [fe80::fc16:3eff:fedf:c527%616533]:123
Nov 11 01:40:34 s0lp3 ntpd[2426]: Listen normally on 542174 qvo92509b39-cf [fe80::a489:5ff:fe82:d27%616535]:123
Nov 11 01:40:34 s0lp3 ntpd[2426]: Listen normally on 542175 qvb92509b39-cf [fe80::d8b1:d4ff:fe48:a44d%616536]:123
Nov 11 01:40:34 s0lp3 ntpd[2426]: Deleting interface #542166 tap3ca379f2-d1, fe80::fc16:3eff:fe6e:5ef7%616526#123, interface stats: received=0, sent=0, dropped=0, active_time=57 secs
Nov 11 01:40:34 s0lp3 ntpd[2426]: new interface(s) found: waking up resolver
Nov 11 01:40:37 s0lp3 ntpd[2426]: bind(122) AF_INET6 fe80::fc16:3eff:fea1:a01c%616537#123 flags 0x11 failed: Cannot assign requested address
Nov 11 01:40:37 s0lp3 ntpd[2426]: unable to create socket on tap92509b39-cf (542176) for fe80::fc16:3eff:fea1:a01c%616537#123
Nov 11 01:40:37 s0lp3 ntpd[2426]: failed to init interface for address fe80::fc16:3eff:fea1:a01c%616537
Nov 11 01:40:39 s0lp3 ntpd[2426]: Listen normally on 542177 tap92509b39-cf [fe80::fc16:3eff:fea1:a01c%616537]:123
Nov 11 01:40:39 s0lp3 ntpd[2426]: new interface(s) found: waking up resolver
Nov 11 01:40:52 s0lp3 ntpd[2426]: Deleting interface #542172 tap3ca379f2-d1, fe80::fc16:3eff:fe6e:5ef7%616532#123, interface stats: received=0, sent=0, dropped=0, active_time=18 secs
Nov 11 01:40:54 s0lp3 ntpd[2426]: Deleting interface #542163 qvo3ca379f2-d1, fe80::14ad:deff:fe5b:4165%616523#123, interface stats: received=0, sent=0, dropped=0, active_time=81 secs
Nov 11 01:40:54 s0lp3 ntpd[2426]: Deleting interface #542164 qvb3ca379f2-d1, fe80::7cf6:4dff:fe23:b119%616524#123, interface stats: received=0, sent=0, dropped=0, active_time=81 secs
Nov 11 01:41:05 s0lp3 ntpd[2426]: ./../lib/isc/unix/ifiter_getifaddrs.c:163: INSIST(ifa->ifa_name != ((void *)0)) failed
Nov 11 01:41:05 s0lp3 ntpd[2426]: exiting (due to assertion failure)

[Christian Ehrhardt  (paelzer)]

I'm so glad we switched to chrony after 18.04 as ntp server (and systemd-timesyncd as default ntp client) as this is just a pain in NTP.
I think this is the same (a newer version of) bug 1069543 therefore marking it as a dup.