Re: 2.6.36-rc3: EIP is at scsi_init_io+...

From: Jens Axboe
Date: Thu Sep 09 2010 - 07:01:16 EST


On 2010-09-09 02:12, Linus Torvalds wrote:
> Hmm. No noise about this one.
>
> Jens, Fujita, James, any comments?
>
> On Mon, Aug 30, 2010 at 11:46 AM, Alexey Dobriyan <adobriyan@xxxxxxxxx> wrote:
>> Not much of a calltrace, it scrolled away because of hardlockup detector.
>> On the bright side, radeon KMS worked correctly and actually showed it.
>>
>> $ addr2line -e vmlinux ffffffff812d207b
>> drivers/scsi/scsi_lib.c:1015
>>
>> 1012 err_exit:
>> 1013 scsi_release_buffers(cmd);
>> 1014 scsi_put_command(cmd);
>> 1015 ===> cmd->request->special = NULL; <===
>> 1016 return error;
>> 1017 }
>> 1018 EXPORT_SYMBOL(scsi_init_io);
>
> I do have to say that it looks rather wrong that it accesses "cmd"
> after it has done the "scsi_put_command(cmd)" on it.
>
> I also note that that was introduced pretty recently by commit
> 610a63498f7 ("scsi: fix discard page leak"), merged during this merge
> window. That does look suspicious to me.

Agree, that's clearly a bug. That assignment should just go away.

--
Jens Axboe

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