CentOS - Apr 2015 - CentOS 7.1 user login screen can't scroll up/down

After we upgraded our CentOS 7.0 desktops to CentOS 7.1, a critical 
error in the graphical login screen has appeared on all 7.1 machines:

We have 100+ users defined in /etc/passwd, and a list of names is 
presented on the initial login screen.  However, it's impossible to 
scroll up or down in this user list to select the desired user.  The 
middle mouse button seems to be disabled, so scrolling has become 
impossible!  One can use the left and right mouse buttons to select one 
of the users in view, but no one else.

This seems definitely to be a critical bug in CentOS 7.1.

Workarounds:

1. Log in non-graphically using Ctrl-Alt-F2, then run the command startx.

2. Trim down /etc/passwd to 1 (or a few) relevant users.

-- 
Ole Holm Nielsen
Department of Physics, Technical University of Denmark

On 2015-04-09, Ole Holm Nielsen
<Ole.H.Nielsen at fysik.dtu.dk> wrote:
> After we upgraded our CentOS 7.0 desktops to CentOS 7.1, a critical
> error in the graphical login screen has appeared on all 7.1 machines:
>
> We have 100+ users defined in /etc/passwd, and a list of names is
> presented on the initial login screen.  However, it's impossible to
> scroll up or down in this user list to select the desired user.  The
> middle mouse button seems to be disabled, so scrolling has become
> impossible!  One can use the left and right mouse buttons to select
> one of the users in view, but no one else.
>
> This seems definitely to be a critical bug in CentOS 7.1.
>
> Workarounds:
>
> 1. Log in non-graphically using Ctrl-Alt-F2, then run the command
> startx.
>
> 2. Trim down /etc/passwd to 1 (or a few) relevant users.
>
3. Disable the user list:
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Desktop_Migration_and_Administration_Guide/customizing-login-screen.html

-- 

Liam

Can you use the page-down and arrow keys to navigate the list? Which Display 
Manager ( [kxg]dm ) are you using? Try a different one if the keyboard 
navigation does not work.

On 04/09/2015 09:17 AM, Ole Holm Nielsen wrote:
> After we upgraded our CentOS 7.0 desktops to CentOS 7.1, a critical error
in
> the graphical login screen has appeared on all 7.1 machines:
>
> We have 100+ users defined in /etc/passwd, and a list of names is presented
on
> the initial login screen.  However, it's impossible to scroll up or
down in
> this user list to select the desired user.  The middle mouse button seems
to
> be disabled, so scrolling has become impossible!  One can use the left and 
> right mouse buttons to select one of the users in view, but no one else.
>
> This seems definitely to be a critical bug in CentOS 7.1.
>
> Workarounds:
>
> 1. Log in non-graphically using Ctrl-Alt-F2, then run the command startx.
>
> 2. Trim down /etc/passwd to 1 (or a few) relevant users.
>
>
> -- 
>
>
> *********************************************************
> David P. Both, RHCE
> Millennium Technology Consulting LLC
> Raleigh, NC, USA
> 919-389-8678
>
> dboth at millennium-technology.com
>
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> www.databook.bz - Home of the DataBook for Linux
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On 04/09/2015 08:17 AM, Ole Holm Nielsen wrote:
> After we upgraded our CentOS 7.0 desktops to CentOS 7.1, a critical
> error in the graphical login screen has appeared on all 7.1 machines:
> 
> We have 100+ users defined in /etc/passwd, and a list of names is
> presented on the initial login screen.  However, it's impossible to
> scroll up or down in this user list to select the desired user.  The
> middle mouse button seems to be disabled, so scrolling has become
> impossible!  One can use the left and right mouse buttons to select one
> of the users in view, but no one else.
> 
> This seems definitely to be a critical bug in CentOS 7.1.
> 
> Workarounds:
> 
> 1. Log in non-graphically using Ctrl-Alt-F2, then run the command startx.
> 
> 2. Trim down /etc/passwd to 1 (or a few) relevant users.
> 
This is an upstream bug:

https://bugzilla.redhat.com/show_bug.cgi?id=1184802

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> This is an upstream bug:
>
> https://bugzilla.redhat.com/show_bug.cgi?id=1184802
Great, thanks for the info!  Now we just need a bug fix :-)

/Ole

> Can you use the page-down and arrow keys to navigate the list? Which
Display
> Manager ( [kxg]dm ) are you using? Try a different one if the keyboard
> navigation does not work.
No, page up/down and arrows don't work either.

Display Manager: Whatever comes with CentOS 7.1 (cannot be changed at 
the login screen).

Johnny Hughes informed us that an upstream bug has been reported:
https://bugzilla.redhat.com/show_bug.cgi?id=1184802

/Ole

> 3. Disable the user list:
>
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Desktop_Migration_and_Administration_Guide/customizing-login-screen.html
I mentioned two other workarounds myself. I prefer to wait for the 
upstream bug to be solved: 
https://bugzilla.redhat.com/show_bug.cgi?id=1184802

/Ole

Liam O'Toole wrote:
> On 2015-04-09, Ole Holm Nielsen
> <Ole.H.Nielsen at fysik.dtu.dk> wrote:
>> After we upgraded our CentOS 7.0 desktops to CentOS 7.1, a critical
>> error in the graphical login screen has appeared on all 7.1 machines:
>>
>> We have 100+ users defined in /etc/passwd, and a list of names is
>> presented on the initial login screen.  However, it's impossible to
>> scroll up or down in this user list to select the desired user.  The
>> middle mouse button seems to be disabled, so scrolling has become
>> impossible!  One can use the left and right mouse buttons to select
>> one of the users in view, but no one else.
>>
>> This seems definitely to be a critical bug in CentOS 7.1.
<snip>
Isn't there a way to open a box for "other user"?
> 3. Disable the user list:
>
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Desktop_Migration_and_Administration_Guide/customizing-login-screen.html
This, in fact, *is* the correct answer. That it's enabled is bad.

1. Security. Having the username, which someone being nasty wants to
     break into, but doesn't know it, this is just that much easier.
2. You have over 100 users. That's annoying to scroll through. Certainly,
     each user *ought* to know their own username, and it's faster to
     type it in, than scroll down 5 or so names at a time through 100+.
3. See 1.

         mark