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Date: Sun, 24 Aug 2014 21:31:14 +0200
From: Peter Lieven <pl@kamp.de>
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Subject: Re: [Qemu-devel] [Fwd: [PATCH v4 07/21] iscsi: Handle failure for
 potentially large allocations]
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To: Paolo Bonzini <pbonzini@redhat.com>, Kevin Wolf <kwolf@redhat.com>
Cc: benoit.canet@irqsave.net, maxa@catit.be, qemu-devel@nongnu.org, stefanha@redhat.com

Am 24.08.2014 um 18:30 schrieb Paolo Bonzini:
> Il 22/08/2014 10:42, Kevin Wolf ha scritto:
>>> Unfortunately, I missed that one. The zeroblock is typicalls 512 Byte or 4K depending
>>> on the blocksize.
>> I don't remember the details, but I think when I went through all
>> drivers, I couldn't convince myself that a reasonable block size is
>> enforced somewhere. So I just went ahead and converted the call to be on
>> the safe side. It can never hurt anyway.
> Yeah, a malicious iSCSI target could have unreasonable block sizes.
Maybe we should just allow 512b or 4kb blocksize and refuse
all other?

Peter

>
> This means the minimum transfer size for SCSI devices could be on the
> order of half a GiB, and that could cause other unbounded allocations in
> the read-modify-write code.  Are those protected too?
>
> Paolo