linux-kernel - Re: xfslogd-spinlock bug?

lists.openwall.net		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 linux-cve-announce 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:	Tue, 19 Dec 2006 09:36:37 +1100
From:	David Chinner <dgc@....com>
To:	Haar János <djani22@...center.hu>
Cc:	David Chinner <dgc@....com>, linux-xfs@....sgi.com,
	linux-kernel@...r.kernel.org
Subject: Re: xfslogd-spinlock bug?

On Mon, Dec 18, 2006 at 09:17:50AM +0100, Haar János wrote:
> From: "David Chinner" <dgc@....com>
> > > The NBD serves through eth1, and it is on the CPU3, but the ide0 is on
> the
> > > CPU0.
> >
> > I'd say your NBD based XFS filesystem is having trouble.
> >
> > > > Are you using XFS on a NBD?
> > >
> > > Yes, on the 3. source.
> >
> > Ok, I've never heard of a problem like this before and you are doing
> > something that very few ppl are doing (i.e. XFS on NBD). I'd start
> > Hence  I'd start by suspecting a bug in the NBD driver.
> 
> Ok, if you have right, this also can be in context with the following issue:
> 
> http://download.netcenter.hu/bughunt/20061217/messages.txt   (10KB)

Which appears to be a crash in wake_up_process() when doing memory
reclaim (waking the xfsbufd).

> > > > > Dec 16 12:08:36 dy-base RSP: 0018:ffff81011fdedbc0  EFLAGS: 00010002
> > > > > Dec 16 12:08:36 dy-base RAX: 0000000000000033 RBX: 6b6b6b6b6b6b6b6b
> RCX:
> > > >                                                      ^^^^^^^^^^^^^^^^
> > > > Anyone recognise that pattern?

Ok, I've found this pattern:

#define POISON_FREE 0x6b

Can you confirm that you are running with CONFIG_DEBUG_SLAB=y?

If so, we have a use after free occurring here and it would also
explain why no-one has reported it before.

FWIW, can you turn on CONFIG_XFS_DEBUG=y and see if that triggers
a different bug check prior to the above dump?

Cheers,

Dave.
-- 
Dave Chinner
Principal Engineer
SGI Australian Software Group
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/