Re: EXT3 fuzzing

[Eric Sandeen <sandeen@redhat.com>]

Eric Sesterhenn / Snakebyte wrote:
> hi,
> 
> after fsfuzz
> (http://www.securityfocus.com/archive/1/449568/30/0/threaded) was
> released i decided to give it a spin. So far I got two problematic
> images:
> 
> http://www.cobra-basket.de/ext3_ls_prozzy_hog.img.bz2
> 	which makes the kernel use as much cpu as it can get
> 
> http://www.cobra-basket.de/ext3_memhog.img.bz2
> 	eats all memory it can get
> 
> I enabled jbd debugging for a while, and the traces looked
> similar, but made not much sense to me. kmemleak
> locked my box, so I was not able to get some debugging
> info from there.
> To test the images, just mount them, and do an ls
> on the image.

Hi Eric, I recently posted a patch to LKML ([PATCH] handle ext3 directory 
corruption better) to handle the broken fuzz cases I found.  You might try again 
w/ that patch... I can also give your images a whirl.  With the patch I 
submitted, I had thousands of successful fsfuzz runs.  The only snag I hit was 
actually an fsfuzz bug; lost+found/ had been fuzzed so it looked like a pipe, 
and the "cat" part of the test hung up - not really an ext3 bug.

Thanks,

-Eric