From: Kevin Wolf <kwolf@redhat.com>
To: Alexander Popov <alex.popov@linux.com>
Cc: sstabellini@kernel.org, pmatouse@redhat.com,
mdroth@linux.vnet.ibm.com, qemu-block@nongnu.org, mst@redhat.com,
qemu-devel@nongnu.org, qemu-stable@nongnu.org,
John Snow <jsnow@redhat.com>,
pjp@redhat.com
Subject: Re: [Qemu-devel] [Qemu-block] [QEMU-SECURITY] ide: fix assertion in ide_dma_cb() to prevent qemu DoS from quest
Date: Tue, 16 Jul 2019 13:25:35 +0200 [thread overview]
Message-ID: <20190716112535.GB7297@linux.fritz.box> (raw)
In-Reply-To: <0bce1e99-fb98-6354-9426-391a3e9363f1@linux.com>
Am 15.07.2019 um 13:24 hat Alexander Popov geschrieben:
> On 05.07.2019 17:07, Alexander Popov wrote:
> > This assertion was introduced in the commit a718978ed58a in July 2015.
> > It implies that the size of successful DMA transfers handled in
> > ide_dma_cb() should be multiple of 512 (the size of a sector).
> >
> > But guest systems can initiate DMA transfers that don't fit this
> > requirement. Let's improve the assertion to prevent qemu DoS from quests.
>
> Hello!
>
> Just a friendly ping.
>
> Could you have a look at this patch?
John, I think this is for you.
I haven't reviewed this yet, but if we put an assertion there that the
request is aligned, we probably rely on this fact somewhere in the code.
So I suspect that just changing the assertion without changing other
code, too, might not be enough.
Kevin
next prev parent reply other threads:[~2019-07-16 11:26 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-05 14:07 [Qemu-devel] [QEMU-SECURITY] ide: fix assertion in ide_dma_cb() to prevent qemu DoS from quest Alexander Popov
2019-07-05 14:13 ` Alexander Popov
2019-07-15 11:24 ` Alexander Popov
2019-07-16 11:25 ` Kevin Wolf [this message]
2019-07-16 14:57 ` [Qemu-devel] [Qemu-block] " John Snow
2019-07-16 16:18 ` P J P
2019-07-26 0:25 ` [Qemu-devel] " John Snow
2019-07-26 21:09 ` Alexander Popov
2019-11-06 12:05 ` Michael S. Tsirkin
2019-11-06 22:05 ` Alexander Popov
2019-11-14 17:31 ` Alexander Popov
2019-11-06 10:17 ` Alexander Popov
2019-11-06 12:08 ` Michael S. Tsirkin
2019-11-06 22:01 ` Alexander Popov
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