Subject: Re: [vserver] problem with devpts
From: Deniss <dg@sad.lv>
Date: Tue, 18 May 2010 13:54:20 +0300



Herbert Poetzl wrote:
> On Mon, May 17, 2010 at 05:36:17PM +0300, Deniss wrote:
> 
>> Herbert Poetzl wrote:
>>> On Fri, May 07, 2010 at 03:17:04PM +0300, Deniss wrote:
>>>> yeh, looks like the problem is in vprocunhide - when problem arise in
>>>> already open session to guest `ps` stop working
> 
>>>> www ~ # ps -efH
>>>> Error, do this: mount -t proc proc /proc
> 
>>>> when i enter to guset using 'vserver enter' the problem disappears - 
>>>> proc is mounted and ssh working
> 
>>> util-vserver version?
>> zavarka ~ # vserver-info
>> Versions:
>>                    Kernel: 2.6.32.12-vs2.3.0.36.29.4-vserver-intel
>>                    VS-API: 0x00020305
>>              util-vserver: 0.30.216-pre2883; Apr 15 2010, 14:13:08
>>
>> Features:
>>                        CC: i686-pc-linux-gnu-gcc, i686-pc-linux-gnu-gcc 
>> (Gentoo 4.3.4 p1.0, pie-10.1.5) 4.3.4
>>                       CXX: i686-pc-linux-gnu-g++, i686-pc-linux-gnu-g++ 
>> (Gentoo 4.3.4 p1.0, pie-10.1.5) 4.3.4
>>                  CPPFLAGS: ''
>>                    CFLAGS: '-O2 -mtune=native -march=native -pipe 
>> -fomit-frame-pointer -std=c99 -Wall -pedantic -W -funit-at-a-time'
>>                  CXXFLAGS: '-O2 -mtune=native -march=native -pipe 
>> -fomit-frame-pointer -ansi -Wall -pedantic -W -fmessage-length=0 
>> -funit-at-a-time'
>>                build/host: i686-pc-linux-gnu/i686-pc-linux-gnu
>>              Use dietlibc: yes
>>        Build C++ programs: yes
>>        Build C99 programs: yes
>>            Available APIs: v13,net,v21,v22,v23,netv2
>>             ext2fs Source: e2fsprogs
>>     syscall(2) invocation: alternative
>>       vserver(2) syscall#: 273/glibc
>>                crypto api: beecrypt
>>           python bindings: yes
>>    use library versioning: yes
>>
>> Paths:
>>                    prefix: /usr
>>         sysconf-Directory: /etc
>>             cfg-Directory: /etc/vservers
>>          initrd-Directory: $(sysconfdir)/init.d
>>        pkgstate-Directory: /var/run/vservers
>>           vserver-Rootdir: /vservers
> 
>>>> Deniss wrote:
>>>>> hello !
> 
>>>>> i have a problem with devpts on 2.6.32.12-vs2.3.0.36.29.4:
>>>>> sometimes sshd stop allowing to log in with errors:
> 
>>> does it happen on a more recent kernel/patch too?
> 
>> I running 
>> http://people.linux-vserver.org/~harry/patch-2.6.32.12-vs2.3.0.36.29.4-grsec2.1.14-20100503.diff
> 
> maybe the issue is grsec related?
> if you can easily reproduce it, please try without the
> grsec patch and let us know how that goes ...

which version you suggest to try ?

> 
> TIA,
> Herbert
> 
>> that is the latest one patch
> 
>> Note that the problem happens after some time after guest start, and
>> it is enough to run "vprocunhide" again to fix it
> 
>>> TIA,
>>> Herbert
> 
>>>>> May  7 11:01:28 www sshd[1520]: fatal: openpty returns device for which 
>>>>> ttyname fails.
>>>>> May  7 11:01:28 www sshd[1520]: error: chown  0 0 failed: No such file 
>>>>> or directory
>>>>> May  7 11:01:28 www sshd[1520]: error: chmod  0666 failed: No such file 
>>>>> or directory
>>>>> restarting sshd helps
>>>>> i think the problem may be in context leak between host and guest cos 
>>>>> they share /dev/pts as i understand
>>>>> probably the solution may be to use "newinstance" feature of devpts but 
>>>>> i cant manage to get it working.