[DUMB]: Is kernel oops always a kernel bug ???

[DUMB]: Is kernel oops always a kernel bug ???

[Linux Geek]

Hi all ,

If a kernel oops,  then is the problem always with the kernel ? Can't a 
user proggie ( running as root ) do something insane and make the
kernel oops ?

TIA

Re: [DUMB]: Is kernel oops always a kernel bug ???

[Jurriaan]

From: Linux Geek <bourne@ToughGuy.net>
Date: Fri, Jan 17, 2003 at 11:33:46AM +0530
> Hi all ,
> 
> If a kernel oops,  then is the problem always with the kernel ? Can't a 
> user proggie ( running as root ) do something insane and make the
> kernel oops ?
> 
That shouldn't happen - it's called DOS (Denial-Of-Service) if a user
program can make the kernel oops. Some of these probably still exist in
the linux kernel, nothing is perfect :-)

But another option exists: hardware failures. If your memory decides to
take a break, you will get an oops also.

Good luck,
Jurriaan
-- 
Holed up in your little room, we talk for hour on empty hour,
pacing up and down between the walls that we have built ourselves.
	New Model Army - Long Goodbye
GNU/Linux 2.5.58 SMP/ReiserFS 2x2752 bogomips load av: 0.16 0.61 0.61

Re: [DUMB]: Is kernel oops always a kernel bug ???

[Valdis.Kletnieks]

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On Fri, 17 Jan 2003 11:33:46 +0530, Linux Geek <bourne@ToughGuy.net>  said:
> If a kernel oops,  then is the problem always with the kernel ? Can't a 
> user proggie ( running as root ) do something insane and make the
> kernel oops ?

At least in theory, there should be *nothing* that can happen in user space
that will kill the kernel.  However, in practice, if a program is running
as root, it can definitely blortch things up.  This is mostly due to the
assumption that the root user has a clue, and that if they are (for instance)
opening /proc/kcore for writing, that they know what they're doing.  Similarly,
if a program opens /dev/hda1 for writing and scribbles over the superblock,
it may be a bit difficult to mount the filesystem.

So in general, yes, the root user can screw things up in the kernel.  On the
other hand, the root user can also 'rm -rf /' which doesn't require any
extraordinary kernel assistance, just the unlink() system call.  The only
solution here is to not give root to clueless bozos, and to take regular
backups. ;)
-- 
				Valdis Kletnieks
				Computer Systems Senior Engineer
				Virginia Tech


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