Re: [Vserver] kernel bug

From: Andreas Baetz <lac01_at_web.de>
Date: Wed 06 Dec 2006 - 11:11:44 GMT
Message-Id: <200612061211.44933.lac01@web.de>

> On Tuesday 28 November 2006 15:54, Herbert Poetzl wrote:
> > On Tue, Nov 28, 2006 at 08:11:35AM +0100, Andreas Baetz wrote:
> > > On Sunday 26 November 2006 23:22, Herbert Poetzl wrote:
> > > > On Fri, Nov 24, 2006 at 08:11:39AM +0100, Andreas Baetz wrote:
> > > > > On Thursday 23 November 2006 18:49, Herbert Poetzl wrote:
> > > > > > On Thu, Nov 23, 2006 at 02:43:13AM +0100, Herbert Poetzl wrote:
> > > > > > >
> > > > > > > thanks, should be fixed in the next release
> > > > > >
> > > > > > vs2.0.2.2-rc8 is out ...
> > > > >
> > > > > I tried vs2.0.2.2-rc8 with 2.6.18.3, the vserver starts ok, no
> > > > > errors, but when I stopped it, the whole system freezed.
> > > > > Right after "Deconfiguring network interfaces...done."
> > > >
> > > > okay, maybe you get around, the stack trace of
> > > > all processes would probably tell us more ...
> > > I wrote down some of the trace output by hand:
> >
> > hmm, the numbers of those dumps would be interesting,
> > especially if you have an unstripped kernel (vmlinux)
> > available, so we can figure _where_ this happens
> >
> > so a serial console or some other means of recording
> > them would be very helpful, if not available, try
> > with a photo camera ...
> >
>
> I did some more tests:
> At console 1:
> host:~# vserver deb4 enter
> deb4:/#
>
> .. Then I stopped all services in deb4 ..
>
> deb4:/# ps ax
> PID TTY STAT TIME COMMAND
> 1 ? Ss 0:00 init [2]
> 4999 ? S+ 0:00 login
> 5023 pts/0 Ss 0:00 /bin/bash -login
> 5043 pts/0 R+ 0:00 ps ax
>
> At console 2:
> host:~# vps ax|grep 8004
> 4999 8004 deb4 tty3 S+ 0:00 login
>
> 5023 8004 deb4 pts/0 Ss+ 0:00 /bin/bash -login
> 5049 0 MAIN tty2 S+ 0:00 grep 8004
>
> At console 1:
> deb4:/# <hit CTRL-D>
>
> EIP: [<e2fd8894>] 0xe2fd8894 SS:ESP 0068:e4711f20
> <1>Fixing recursive fault but reboot is needed!
> host kernel: Oops: 0002 [#1]
> host kernel: PREEMPT
> host kernel: CPU: 0
> host kernel: EIP is at 0xe2fd8894
> host kernel: eax: e2fd8888 ebx: e2fd8930 ecx: 00000001 edx: 00000001
> host kernel: esi: 00000000 edi: e2fd8890 ebp: e4711f48 esp: e4711f20
> host kernel: ds: 007b es: 007b ss: 0068
> host kernel: Process vcontext (pid: 4638[#8004], ti=e4710000 task=e4334ab0 task.ti=e4710000)
> host kernel: Stack: c01195e3 e2fd8888 00000001 00000000 00000000 00000001 00000001 00000000
> host kernel: 00000001 00000286 e4711f6c c011b1af 00000000 00000000 00000001 e2fd8890
> host kernel: e4711f9c e4334ab0 00000010 c17efa90 c01224b9 00000000 00000000 c011ac30
> host kernel: Call Trace:
> host kernel: Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 94 88 fd e2 <30> 89 fd e2 02 00 00 00 00 00 00 00 2f 65 74 63 2f 76 73 65 72
> host kernel: EIP: [<e2fd8894>] 0xe2fd8894 SS:ESP 0068:e4711f20

some more info:
I copied the / of a working vserver and used it as / of deb4.
"vserver deb4 stop" now works.
It seems that something inside the / of the old deb4 is causing
the system to crash when no more processes are running with that xid.

So if a user of a certain vserver manages to create that condition in a vserver,
then ending all processes in that vserver, the user could manage to crash the host.

Andreas

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