Arch Linux

abarur

Member

Registered: 2020-03-14

Posts: 3

[SOLVED] Login freeze with memory overflow

I have installed archlinux on a Lenovo Thinkstation. The installation was straightforward without issue, and could log into local accounts normally. Because this machine is on my workplace, I installed NIS accounts and added NFS disks to automount on startup in /etc/fstab.

After setting up the NIS client, I could log into NIS accounts normally. However I cannot log into local account, whether from tty or from a login manager. The symptoms are as follows:
1. In tty, I enter the local account username, press enter, then the password and press enter
2. Then the machine freezes for several minutes
3. After that, it prints timeout error and, while still being laggy for sometime, I get control back

I realized afterwards that as I press enter after entering the password, memory gets filled up rapidly, until it causes the freeze.

Things to note:
- I can still use su command to log into local user account with no problem. Only loging in from tty or login manager causes this issue
- I can log into root account just fine, via tty or su.
- SSH into local account also causes this issue. SSH into NIS account is fine.
- I could link to issue to a similar freeze I had when running CUPS, with out of memory causing a freeze. I believe this is due to CUPS trying to use local account cups.

Here are config files related to NIS configuration, as the issue might come from these.

# /etc/nsswitch.conf
passwd: files nis mymachines systemd
group: files nis mymachines systemd
shadow: files

publickey: files

hosts: files myhostname dns nis
networks: files

protocols: files
services: files
ethers: files
rpc: files

netgroup: files

# /etc/host.conf
order hosts,bind,nis
multi on

Things I tried:
- I tested several NIS configurations. When NIS accounts are ok, local accounts (except root) have this issue. When NIS accounts are disabled, local accounts become fine.
- A thread from linuxquestions.org (cant find again the url) talked about /etc/.pwd.lock causing the out of memory issue. Removing the file then rebooting did not solve the issue.

So I am suspecting the problem comes from PAM or polkit, but cannot pinpoint it yet.
I ask for help in debugging this mysterious problem, so that I log into local account as well as NIS account, for using a Window manager for example. I had already installed NIS on another computer without problem (I use the same config from this computer).

Thanks you very much for your feedback and help.
Cheers.

Last edited by abarur (2020-03-19 09:41:33)

Zod

Member

From: Hoosiertucky

Registered: 2019-03-10

Posts: 636

Re: [SOLVED] Login freeze with memory overflow

You might have a look at these...especially the first one..

https://bugzilla.redhat.com/show_bug.cgi?id=1705641
https://bugzilla.redhat.com/show_bug.cgi?id=1716382

abarur

Member

Registered: 2020-03-14

Posts: 3

Re: [SOLVED] Login freeze with memory overflow

It looks very similar to my issue indeed! Thanks a lot for the pointers.
I am testing this as soon as I can and will be back.

abarur

Member

Registered: 2020-03-14

Posts: 3

Re: [SOLVED] Login freeze with memory overflow

Huge thanks Zod! Enabling NSCD solved it!

# systemctl start nscd

I had searched much on this issue before posting but never found anything related to NSCD.
All material I read on NIS installation, including Arch wiki, never mentioned NSCD, that is quite surprising.