From: Ewan Milne <emilne@redhat.com>
To: Joe Lawrence <Joe.Lawrence@stratus.com>
Cc: linux-scsi@vger.kernel.org,
"James E.J. Bottomley" <JBottomley@parallels.com>
Subject: Re: [PATCH] st: Take additional queue ref in st_probe
Date: Mon, 04 Mar 2013 13:13:31 -0500 [thread overview]
Message-ID: <1362420811.18372.143.camel@localhost.localdomain> (raw)
In-Reply-To: <alpine.DEB.2.02.1303041101450.1736@jlaw-desktop.mno.stratus.com>
On Mon, 2013-03-04 at 11:14 -0500, Joe Lawrence wrote:
> These changes were applied to scsi.git, branch "misc". This patch
> fixes a reference count bug in the SCSI tape driver which can be
> reproduced with the following:
>
> * Boot with slub_debug=FZPU, tape drive attached
> * echo 1 > /sys/devices/... tape device pci path .../remove
> * Wait for device removal
> * echo 1 > /sys/kernel/slab/blkdev_queue/validate
> * Slub debug complains about corrupted poison pattern
The incorrect reference count fixed by this patch is almost certainly
responsible for OOPSes seen with tape devices connected using zfcp
on the s390x architecture due to a use-after-free. I was able to
reproduce the problem with scsi_debug ptype=1 and slub_debug enabled.
So, st device support is broken. With the patch, the problem no longer
appears.
-Ewan <emilne@redhat.com>
next prev parent reply other threads:[~2013-03-04 18:13 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-04 16:14 [PATCH] st: Take additional queue ref in st_probe Joe Lawrence
2013-03-04 18:13 ` Ewan Milne [this message]
2013-03-04 23:42 ` Seymour, Shane M
2013-03-05 12:39 ` Jan Vesely
2013-03-05 15:57 ` [PATCH v2] " Joe Lawrence
2013-03-05 17:17 ` Kai Makisara
2013-03-05 17:34 ` James Bottomley
2013-03-15 9:13 ` Jan Vesely
2013-03-15 12:51 ` Ewan Milne
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