Silly Kernel Panic in Mac OS X 10.2.2

shibby tells us that it is easy to cause a kernel panic in Mac OS X 10.2.2, by attempting to move a directory into the same location as another one of the same name, using Terminal: mkdir ~/mydir; cd ~/mydir; mkdir mydir; mv mydir ... Kernel panic is instant. Save all your documents and quit your open apps if you feel the need to see it for yourself. Happy Thanksgiving!

Comments

Works just fine on my system.... (in Bash, though)

[ewwhite]

I was able to create a directory and move a directory of the same name into it. Bash is my default shell. Try the same thing in Bash. exx@eddy:~/mydir/mydir$

Re:Why?

[Elwood P Dowd]

Well, Avie Tevinian probably doesn't agree with your "OS people up at Carnegie Mellon", and he's running the show over at Apple. He also wrote some pertinent versions of Mach, up at Carnegie Mellon.

When it comes to questions like this, if you can get the best people, using their prefered tools is often a good idea. If Apple could have hired all the architects of the freebsd Kernel, then sure, maybe you'd be right.

Also, I don't know what the hell you mean that you've "heard nothing but bad things about" Mach. It's a well known and well inspected peice of code. It might have problems, but saying "bad things" doesn't mean anything. What are the problems? Message passing is slow? This is true. Whatever. It's an architectural choice. Some of those architectural choices are exactly what makes Mach good for Apple - Multiple OS hosting.

Re:I hope you submited to Apple

[JMZorko]

Awhile ago, before Jaguar, I (inadvertently) found a way to make Mac OS X 10.1.something kernel panic, by writing some absolutely horrid BSD sockets code (the kind you write when you're trying to help a fellow developer but you've not slept in far too long). I submitted it to Apple via the darwin-dev list, and they were very hip on fixing it. A software update including the fix was available I think two weeks later.

Now, i'm sure they had other things in that update, and it wasn't just on my account, but they thought it important enough to roll it in anyway. I thought that was the coolest thing :-)

Regards,

John

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Re:They know ....

[valmont]

you are missing the point here. It works this way:

1. user accidentally finds bug in OS
2. user talks about it on open-source forums and other places on the internet
3. Apple gets notified as well as open-source community at large
4. within minutes of its discovery, some geeks manage to find the root of the problem
5. apple developers are notified of geeks' findings, confirm, fix, and thoroughly test the fix.
6. within days apple users get a software update notification if bug is important, or fix is rolled into the next major sub-dot release if fairly inconsequential for the broader user base, as it might be the case for this one

You see, apple users don't need to do shit. All i know is that some bug that is fairly inconsequential to me was found, and that it's guna get fixed, fast, and my next OS X release will be all the stronger, and all i'll have to do is click the "install" button when prompted, and i will feel warm and fuzzy all over. I don't even need to what a fucking kernel is.

now that's just me. Yes, many geeks out there will gladly hunt-down the bug in the source code and recompile their kernel.

The point is, you know problems are addressed in an appropriate matter.

So yes, open-source, is, indeed, so much better than anything else, especially if you're dealing with what i consider in my little world, the mission-critical piece of software that is my tibook's operating system.

Such process shows me that a product that relies heavily on mature open-source components is less likely to cause productivity-killing crashes and loss of data such as the ones i've experienced with my previous dell laptop running win2k, as described in one of my journal entries.

And if was to direct an IT department, gee, i just may consider putting a flat-panel iMac on every employee's desktop. Shit i could mount user directories from a central location, enabling employees to switch work stations, i would uniformely configure all machines, prevent users from writing files or installing applications outside of their home directories, i could ssh in each box for sporadic debug work, i could create automated processes to create development environments based on users' needs, wether they're graphic artists or J2EE application developers.

OS X owns you.

this is it people. we are well on our way to reach the nirvana of computing, with symbiotic collaboration between a major hardware and software vendor and the open source community at large, market share gains in each camp benefits the other.

Re:Cool.

[Have Blue]

What's even slicker is that the diagnostic output that used to go all over the screen was instead written to NVRAM, and moved out to disk (~/Library/Logs IIRC) when you rebooted.

WARNING: SHUT DOWN YOUR FTP DAEMON

[Tokerat]

I just tested this over an FTP connection to a Mac OS X 10.2.2 box using Transmit (a Mac FTP client) from a MacOS 9 machine.

I was ABLE to panic the kernel remotely.

This has just taken a violent swing into serious, as ANY USER WITH FTP ACCESS can now drop your Mac OS X machine. Apple needs to patch this, and quickly. I don't care if the security update is 15k to replace /bin/mv, anyone who has an FTP cannot live like this.

Any idea what eactly could be wrong with either the kernel or mv that would cause such a problem? Branching to the wrong case (i.e. branching to the "same name" case as opposed to the "can't replace a directory with an item it contains" case)?

Is this a job for the Darwin team since it involves a BSD component?