Simultaneous cat and external keyboard input causing kernel panic

Simultaneous cat and external keyboard input causing kernel panic

[Timo Jyrinki]

Hi,

I encountered a kernel panic with the 3.1.0 kernel on a Dell Latitude
E6410 while inputting simultaneously from the integrated keyboard with
a cat and from the external keyboard myself. I was trying to type my
password with the external keyboard (pw dialog already visible), but I
noticed that the computer didn't seem responsive to my typing. Then
suddenly the cat shifted his position and there was a kernel panic
involving input handling. I'm now using i8042.nokbd kernel parameter
as a workaround, something I've found useful also earlier.

I wonder if anyone else is experiencing similar problems? This didn't
seem to happen with 3.0, which was the first kernel version I used on
this E6410. Although it has to be noted that the internal keyboard
input was not yet as heavy either at that time. Please test if you can
reproduce the problem.

Photos of the panic at http://people.debian.org/~timo/kernelpaniccat/.
The first one was taken about ten seconds after the panic and shows
the original cat positioning. The two other ones show alternative
possible positions together with more of the panic text. There is also
one photo showing the pre-crash setup, which I happened to take
without anticipating a panic. The similar but black input weight was
not in use.

The kernel was tainted because the Intel "mei" module from staging was
loaded. The kernel used was the final 3.1 from the ubuntu mainline ppa
archives for amd64.

Thank you,

Timo Jyrinki

Re: Simultaneous cat and external keyboard input causing kernel panic

[Clemens Ladisch]

Timo Jyrinki wrote:
> Then suddenly the cat shifted his position and there was a kernel panic

Your cat wanted to find out what the magic in "magic SysRq key" means
and pressed Alt+SysRq+C.  The problem is that he did not consult
Documentation/sysrq.txt first; the "C" does _not_ stand for "catnip".


Regards,
Clemens

Re: Simultaneous cat and external keyboard input causing kernel panic

[Henrique de Moraes Holschuh]

On Thu, 03 Nov 2011, Clemens Ladisch wrote:
> Timo Jyrinki wrote:
> > Then suddenly the cat shifted his position and there was a kernel panic
> 
> Your cat wanted to find out what the magic in "magic SysRq key" means
> and pressed Alt+SysRq+C.  The problem is that he did not consult
> Documentation/sysrq.txt first; the "C" does _not_ stand for "catnip".

Yes, it was a catastrophe.

Truth is, cats are great panic generators and as fuzzy beings themselves,
they're also great fuzzers.  Only, normally they restrict themselves to
fuzzing clothes, computer fans, their owner's food, spreadsheets, the nose
of anyone alergic to catty fuzzy feelings in a 100m radius, word
processors, and IRS forms.

However, it is the first time I've seen documented proof that a cat
sucessfully fuzzed an input device into a panic.  Must be a lolcat's revenge
to the lack of mouses since touchpads took over.  And Linux has no
cat-proofing for the keyboard and touchpads[1], which will leave us
wide-open to surprise fuzzer attacks from the lolcats!  Maybe we should
issue a CVE about it?

;-)

[1] Windows _has_ third-party cat-proofing for keyboards, by detecting
clustered pressing of nearby keys.  I don't think it can yet figure out a
catpaw press on the touchpad, however.

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh