Re: local DDOS? Kernel panic when accessing /proc/ioports

["linux-os \(Dick Johnson\)" <linux-os@analogic.com>]

On Fri, 5 Aug 2005, Martin Loschwitz wrote:

> On Fri, Aug 05, 2005 at 03:40:26PM -0400, linux-os (Dick Johnson) wrote:
>>
>> On Fri, 5 Aug 2005, Martin Loschwitz wrote:
>>
>>> Hi folks,
>>>
>>> I just ran into the following problem: Having updated my box to 2.6.12.3,
>>> I tried to start YaST2 and noticed a kernel panic (see below). Some quick
>>> debugging brought the result that the kernel crashes while some user (not
>>> even root ...) tries to access /proc/ioports. Is this a known problem and
>>> if so, is a fix available?
>>>
>>> Ooops and ksymoops-output is attached.
>>>
>>
>> This can happen if a module is unloaded that doesn't free its
>> resources! Been there, done that.
>>
>
> "This can happen" is not an acceptable explanation, I think. Modules should

Of course it is. You find the module that isn't freeing it's
resources, fix it, and you don't get the panic when you access
/proc/ioports. It's really that simple.

Thinking that modules shouldn't be able to kill the kernel isn't
goint to help. Everything that runs inside the kernel has the
necessary priviliges to destroy anything in the kernel.

> not be able to kill the kernel -- apart from that, I can trigger the bug in
> the very early "ash-system" that KNOPPIX provides. At that time, the modules
> listed below were the only ones loaded -- no others, and I am also sure that
> until that point, no modules were unloaded.
>
> sbp2 ohci1394 usb_storage ub ehci_hcd usbcore
>
> --
>  .''`.   Martin Loschwitz           Debian GNU/Linux developer
> : :'  :  madkiss@madkiss.org        madkiss@debian.org
> `. `'`   http://www.madkiss.org/    people.debian.org/~madkiss/
>   `-     Use Debian GNU/Linux 3.0!  See http://www.debian.org/
>

Cheers,
Dick Johnson
Penguin : Linux version 2.6.12 on an i686 machine (5537.79 BogoMips).
Warning : 98.36% of all statistics are fiction.
.
I apologize for the following. I tried to kill it with the above dot :

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