lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Wed, 05 Nov 2008 10:16:49 -0600
From:	Eric Sandeen <>
To:	Cryptooctoploid <>
CC:	Theodore Tso <>, Roc Valles <>,
Subject: Re: data corruption with ext4 (from exposed by rtorrent

Cryptooctoploid wrote:
> On Mon, Nov 3, 2008 at 2:40 PM, Theodore Tso <> wrote:
>> On Mon, Nov 03, 2008 at 12:42:11PM +0000, Roc Valles wrote:
>>> Some person already reported this. I'm having the same problem.
>>> rtorrent is a bittorrent client that makes heavy use of mmap instead
>>> of read/write to avoid needless duplication of data. It has exposed
>>> other bugs in the past (mmap bug in 2.6.19).
>>> Downloading a big torrent (>2GB) with rtorrent triggers it more times
>>> than not. The bigger the torrent, the higher the likeliness of
>>> failure. When the torrent is finished, if a hash check is forced by
>>> pressing control-r on the torrent, some blocks will fail.
>> Can both of you send the output of "dumpe2fs -h /dev/<disk device>" of
>> the filesystem in question?  The thing which I'm most interested in is
>> whether the extents feature was enabled or not.  (i.e., was this a
>> freshly made ext4 filesystem, or a ext3 filesystem mounted under ext4,
>> and with which features eanbled?)
> I tested this further and it turned out that this bug is not extents
> related. I get the same hash failures on a partition formatted with:
> -O "^extent".

Thanks, that's good information.

> Besides the torrent failures,  ext4 also managed to corrupt two
> dspam sqlite3 databases on my system. (After the corruption I
> get the following error:
> *** glibc detected *** dspam: free(): invalid pointer: 0x0000000001e71c58 ***
> ======= Backtrace: =========
> /lib/[0x7fcd1f941af6]
> /lib/[0x7fcd1f942f3d]
> /usr/lib64/dspam/[0x7fcd1ea03075]
> /usr/lib/[0x7fcd1fc3c710]
> /usr/lib/[0x7fcd1fc3cf49]
> dspam(process_message+0xb49)[0x408579]
> dspam(process_users+0x57d)[0x40902d]
> dspam(main+0x2c2)[0x409832]
> /lib/[0x7fcd1f8e848d]
> dspam[0x402f79
> and the only solution is to restore the database from ext3 backup)

I think this would more likely indicate a userspace bug, though, not
something related to ext4.


> My conclusion is that ext4 is not yet ready for prime time.
> I moved all my data back to ext3.
> --
> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
> the body of a message to
> More majordomo info at

To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists