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Date: Thu, 09 Sep 2010 08:16:49 -0500
From: Anthony Liguori <anthony@codemonkey.ws>
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Subject: Re: [Qemu-devel] [PATCH] raw: Fix image header protection
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To: Kevin Wolf <kwolf@redhat.com>
Cc: qemu-devel@nongnu.org

On 09/09/2010 08:02 AM, Kevin Wolf wrote:
>>>    Or instead of completely removing it, we could add
>>> a size limit, though I suspect that would mean violating some specs.
>>>
>>>        
>> One thing I was thinking of trying was splitting off the first sector
>> into a linear buffer, then allocating a new iovec and adjusting the new
>> iovec to cover the new request minus the first sector.
>>      
> That doesn't help any of the other use cases. Either we consider it a
> problem or not. If we do, it must be fixed everywhere.
>    

Yes, it's a problem.  In other places in the code base, we go to 
incredible lengths to avoid unbounded allocations.

I think we have to two choices: 1) refactor all of the code to not 
require qemu_iovec_to_buffer() or 2) cap the request size and fail a 
request if it's greater.

Regards,

Anthony Liguori

> Kevin
>