Re: v2.6.31-rc6: BUG: unable to handle kernel NULL pointer dereference at 0000000000000008

[Dave Young <hidave.darkstar@gmail.com>]

On Thu, Aug 20, 2009 at 4:00 PM, Eric W. Biederman<ebiederm@xmission.com> wrote:
> Dave Young <hidave.darkstar@gmail.com> writes:
>
>> On Thu, Aug 20, 2009 at 2:07 PM, Eric W. Biederman<ebiederm@xmission.com> wrote:
>>>
>>> ebiederm@xmission.com (Eric W. Biederman) writes:
>>>
>>>> I'm not certain who I should route this too, but I just had 2.6.31-rc6
>>>> fall over on me.  I don't know how reproducible this will be but
>>>> I have a full crash dump if someone is interested in looking into this.
>>>
>>> Looks like I was wrong.  This is appears trivial to reproduce,
>>> I have just reproduced it two more times in a row.  I think
>>> the problem is pty related.
>>>
>>> I was looking into a change in behavior on 2.6.31-rc6 where
>>> data was being lost, and it appears one variant of my test program
>>> kills the kernel.
>>>
>>> The following program run as an unprivileged user causes a kernel
>>> panic in about a minute:
>>>
>>> aka
>>>
>>> while :; do ./KernelTtyTest ; done
>>
>> The test app failed for me:
>>
>> read failed: Input/output error
>> lastbytes: '\r\nprocess_cmd read failed: Interrupted system
>> call\r\necho _2_\r\n'
>> Aborted
>
>
> Oh.  It definitely fails.  I just found that when it failed
> about 600 times in a row it took my kernel with it.  I was
> developing it to understand tty interactions, and when I realized
> that the version I had was killing my kernel I sent it out
> as it was a nice self contained test case.

Confirm: I can reproduce on i386 machine.

>
> Eric
>



-- 
Regards
dave