Subject: bug#30396: nscd segfaults on attempt to ssh to .local host

From: George myglc2 Clemmer <[email-masked]>
Date: Thu, 08 Feb 2018 18:22:09 -0500

Hello, 

On 02/08/2018 at 22:30 Ludovic Courtès writes:

> Hi,
>
> George myglc2 Clemmer <[email-masked]> skribis:
>
>> g1@g1 /root/con/30$  ssh e3a.local ; date
>> ssh: Could not resolve hostname e3a.local: Name or service not known
>> Thu Feb  8 13:06:23 EST 2018
>>
>> g1@g1 /root/con/30$ cat /var/log/messages | tail
>> Feb  8 13:06:00 localhost dhclient: DHCPDISCOVER on enp4s0 to 255.255.255.255 port 67 interval 5
>> Feb  8 13:06:05 localhost dhclient: No DHCPOFFERS received.
>> Feb  8 13:06:05 localhost dhclient: No working leases in persistent database - sleeping.
>> Feb  8 13:06:23 localhost vmunix: [52360.780268] nscd[23423]: segfault at 0 ip 00007fb14a3c1606 sp 00007fb1446d82d8 error 4 in libc-2.25.so[7fb14a341000+196000]
>
> ‘nss-mdns’ was upgraded two weeks ago from 0.10 to 0.11.  I can
> reproduce the crash with 0.11 on x86_64.
>
> What does this print:
>
>   guix gc -R $(readlink -f /run/current-system) | grep nss-mdns

g1@g1 ~$   guix gc -R $(readlink -f /run/current-system) | grep nss-mdns
/gnu/store/ms17fp783xqngzad0b38q97q73f9kaii-nss-mdns-0.11

> Perhaps “ssh -6 e3a.local” works?

Nope ...

g1@g1 ~$ ssh -6 e3a.local ; date
ssh: Could not resolve hostname e3a.local: Name or service not known
Thu Feb  8 18:18:31 EST 2018
g1@g1 ~$ cat /var/log/messages | tail
Feb  8 18:18:19 localhost nscd: 580 monitoring directory `/etc` (2)
Feb  8 18:18:19 localhost nscd: 580 monitoring file `/etc/services` (4)
Feb  8 18:18:19 localhost nscd: 580 monitoring directory `/etc` (2)
Feb  8 18:18:31 localhost vmunix: [71087.823297] nscd[587]: segfault at 0 ip 00007f71cfc43606 sp 00007f71c9f5a2d8 error 4 in libc-2.25.so[7f71cfbc3000+196000]
Feb  8 18:18:32 localhost nscd: 591 monitoring file `/etc/hosts` (1)
Feb  8 18:18:32 localhost nscd: 591 monitoring directory `/etc` (2)
Feb  8 18:18:32 localhost nscd: 591 monitoring file `/etc/resolv.conf` (3)
Feb  8 18:18:32 localhost nscd: 591 monitoring directory `/etc` (2)
Feb  8 18:18:32 localhost nscd: 591 monitoring file `/etc/services` (4)
Feb  8 18:18:32 localhost nscd: 591 monitoring directory `/etc` (2)

Thanks - George