From: Vincent Hanquez <vincent.hanquez@eu.citrix.com>
To: Keir Fraser <keir@xen.org>
Cc: Olaf Hering <olaf@aepfle.de>,
"xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>
Subject: Re: [PATCH] xenstored: allow guests to reintroduce themselves
Date: Tue, 9 Aug 2011 11:50:47 +0100 [thread overview]
Message-ID: <4E411107.20103@eu.citrix.com> (raw)
In-Reply-To: <CA66C71E.300C3%keir@xen.org>
On 08/09/2011 11:14 AM, Keir Fraser wrote:
> On 09/08/2011 11:08, "Vincent Hanquez"<vincent.hanquez@eu.citrix.com>
> wrote:
>
>>> xenstored: allow guests to reintroduce themselves
>>>
>>> During kexec all old watches have to be removed, otherwise the new
>>> kernel will receive unexpected events. Allow a guest to introduce itself
>>> and cleanup all of its watches.
>>
>> What about security wise ?
>>
>> Guest userspace suddenly becomes able to do this operation (and DoS themself)
>> where they used to be limited to normal read/write/.. operations.
>
> Guest userspace can already DoS the guest if it has access to xenstore, by
> messing with xenbus I/O connections, for example.
How so ?
It seems we validate userspace packets (at least on linux) before actually putting them on the ring.
--
Vincent
next prev parent reply other threads:[~2011-08-09 10:50 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-01 12:38 [PATCH] xenstored: allow guests to reintroduce themselves Olaf Hering
2011-08-09 8:59 ` Ian Campbell
2011-08-09 9:17 ` Olaf Hering
2011-08-09 9:25 ` Ian Campbell
2011-08-09 9:34 ` Olaf Hering
2011-08-09 10:08 ` Vincent Hanquez
2011-08-09 10:14 ` Keir Fraser
2011-08-09 10:50 ` Vincent Hanquez [this message]
2011-08-09 11:00 ` Keir Fraser
2011-08-09 11:18 ` Vincent Hanquez
2011-08-09 11:31 ` Keir Fraser
2011-08-09 12:33 ` Vincent Hanquez
2011-08-09 11:07 ` Vincent Hanquez
2011-08-09 10:49 ` Olaf Hering
2011-08-09 16:34 ` Ian Jackson
2011-08-09 16:38 ` Ian Jackson
2011-08-09 16:49 ` Ian Jackson
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