Re: Warning and BUG with btrfs and corrupted image

[Eric Sesterhenn <snakebyte@gmx.de>]

* Chris Mason (chris.mason@oracle.com) wrote:
> On Tue, 2009-01-20 at 07:31 +0100, Eric Sesterhenn wrote:
> > Hi,
> > 
> > * Pavel Machek (pavel@suse.cz) wrote:
> >  
> > > Does ext2/3 and vfat survive that kind of attacks? Those are 'in
> > > production' and should survive it...
> > 
> > I regularly (once or twice a week) test 100 corrupted images of 
> > vfat, udf, msdos, swap, iso9660, ext2, ext3, ext4, minix, bfs, befs,
> > hfs, hfs+, qnx4, affs and cramfs on each of my two test machines.
> > 
> > They are all pretty stable, one remaining thing on my list i didnt have
> > time to look into was an issue with fat (msdos) triggering a bug in
> > buffer.c the other is a warning with ext4 in jbd2/checkpoint.c:166
> > 
> > If there is a filesystem you are interested in thats not on the list
> > or that you want me to test a bit more, just let me know
> > 
> 
> squashfs is in the kernel now, that would be good to see as well.  I
> didn't realize you were doing such extensive tests, thanks for doing
> them.

I already tested squashfs. One issue is basically a problem with
the zlib-api for which i just posted a patch here
http://marc.info/?t=123212807300003&r=1&w=2

The other is an overwritten redzone (also reported in this thread
http://marc.info/?l=linux-fsdevel&m=123212794425497&w=2)
Looks like a length parameter is passed to squashfs_read_data
which is bigger than ((msblk->block_size >> msblk->devblksize_log2) +
1), so the kcalloced buffer gets overwritten later. Maybe you want to
take a look at this issue. Those are the only two problems i have
seen so far with ~8000 tested squashfs images.

Greetings, Eric