Simultaneous cat and external keyboard input causing kernel panic (2011) | Hacker News Reader

Simultaneous cat and external keyboard input causing kernel panic (2011)

lore.kernel.org

141 pointsjosephcsible25 comments

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The best photo story I've ever seen!

> > > 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.

Think I'm seeing and reading this for the second time (or am I confusing this with that bug report about a toddler breaking the gnome login screen..?).

But anyway, this bug report is great.

Multiple times, my cat has managed hit a key combination on my desktop that swaps WASD and the arrow keys, which I never knew existed before the first time she did it. I think it's something like Fn+w, but every time it's happened I always forget exactly what it is, and it takes a bit of effort to search for it because I need to actually use the arrow keys to type those letters, which are a pretty important part of the query...

> The similar but black input weight was not in use.

> (or am I confusing this with that bug report about a toddler breaking the gnome login screen..?)

If you can still find this, please share!

I misremembered some detail, it was this one about the cinnamon desktop and its cinnamon-screensaver:

https://github.com/linuxmint/cinnamon-screensaver/issues/354

Regarding the "screensaver as lock screen", there is also this interesting writeup by jwz:

https://www.jwz.org/blog/2021/01/i-told-you-so-2021-edition/

(open in new tab ^^)

But yeah, it wasn't the Gnome login screen.

While searching I also found some issues with cat in the Ubuntu bug tracker:

https://bugs.launchpad.net/ubuntu/+source/unity-greeter/+bug...

https://bugs.launchpad.net/ubuntu/+source/unity/+bug/1463112

Discussed at the time:

Simultaneous cat and external keyboard input causing kernel panic - https://news.ycombinator.com/item?id=3196682 - Nov 2011 (3 comments)

The link to the pictures of the (not useless) use of cat still work! Cool URLs don’t change.

Useful use of cat

All uses of cat are useful.

Some are useful because they actually serve a purpose in the script.

The rest are useful because trolling merlyn is hilarious.

Due to being disabled, to carry the laptop without closing the lid, I must hold it under my armpit, with the screen locked.

Apparently my armpit's input often sends the screen locker process in a busy loop, taking 100% CPU. So I must go to a tty and kill the process to continue.

I've abused slock quite a bit, it seems to endure accidentally extremely large input attempts from inanimate or even animate object sitting on the keyboard for extended periods (although it's faster to fail entry than delete).

The problem with cat-induced bugs is that they are non-reproducible even when the report contains all the steps, because of a cat's non-deterministic nature.

My cat is a born bug-squasher

Ah, another entry for my list: https://gwern.net/review/cat#fuzz-testing

I've been warning for some time about the potential vulnerabilities involving felinus inputtus sources. It should be noted that Apple has already solved this problem some time ago in Catalina, and I believe their fixes even made it into the Darwin codebase. Even though it's BSD, there should still be some interesting insights gleaned from all that fuzzing.

One potential workaround I've found that works with my own white input weight (that looks very similar to the one in the photos) is to use a can opener. I know it sounds strange, but there appears to be some sort of resonant frequency involved that resolves the downward pressure in very short order. YMMV.

I really wanna make a Yarn pun but I safly have no idea what it is or if its relevant to the context

support engineers really appreciate screenshots, but this reporter took it to another level https://people.debian.org/~timo/kernelpaniccat/

I some times help Non native English IT professionals improve their language skills. I would love if anyone had a list or could offer any recommendations of this kid of fluffy but still technical texts to use as reading materials.

TIL, if sufficiently motivated (nice and hot laptop?), cats are also excellent at fuzzing input...

I've been using cats as a source of fuzz for testing code since the 90s.

A case I had when I was a World of Warcraft GM, many years ago:

Them: I want my character undeleted please.

Me: As a policy, we cannot always recover deleted characters. How was it deleted?

Them: My cat deleted it.

Me: Your cat pressed the delete button on the UI, then typed “DELETE” and pressed enter?

Them: Yes

Me: … Okay then.

Should've asked for photographic proof that they have a cat.

All cats are lil babies.

So was a CVE filed for this exploit? Or was it patched in time?

Would that make this a Schrödinger kernel panic?

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