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Message-ID: <84144f020703190135t40e7cebnfa4f8443f514c24d@mail.gmail.com>
Date: Mon, 19 Mar 2007 10:35:46 +0200
From: "Pekka Enberg" <penberg@cs.helsinki.fi>
To: "Andrew Morton" <akpm@linux-foundation.org>
Subject: Re: 2.6.20.3: kernel BUG at mm/slab.c:597 try#2
Cc: "Andreas Steinmetz" <ast@domdv.de>,
       "Linux Kernel Mailinglist" <linux-kernel@vger.kernel.org>,
       linux-scsi@vger.kernel.org
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On 3/19/07, Pekka Enberg <penberg@cs.helsinki.fi> wrote:
> You can see that mempool_free is passing a NULL pointer to
> kmem_cache_free() which doesn't handle it properly. The NULL pointer
> comes from bio_free() where ->bi_io_vec is  NULL because nr_iovecs
> passed to bio_alloc_bioset() was zero.
>
> The question is, why is nr_pages zero in scsi_req_map_sg()?

Note that the following patch I posted only addresses the part where
slab is clearly failing here:

http://lkml.org/lkml/2007/3/19/42

So, while it should fix the oops, there might be a bug lurking in the
SCSI or block layer still.