From: Sasha Levin <levinsasha928@gmail.com>
To: kvm <kvm@vger.kernel.org>
Subject: KVM device assignment and user privileges
Date: Sun, 20 Nov 2011 16:58:32 +0200 [thread overview]
Message-ID: <1321801112.3231.8.camel@lappy> (raw)
Hi all,
I've been working on adding device assignment to KVM tools, and started
with the basics of just getting a device assigned using the
KVM_ASSIGN_PCI_DEVICE ioctl.
What I've figured is that unprivileged users can request any PCI device
to be assigned to him, including devices which he shouldn't be touching.
In my case, it happened with the VGA card, where an unprivileged user
simply called KVM_ASSIGN_PCI_DEVICE with the bus, seg and fn of the VGA
card and caused the display on the host to go apeshit.
Was it supposed to work this way? I couldn't find any security checks in
the code paths of KVM_ASSIGN_PCI_DEVICE and it looks like any user can
invoke it with any parameters he'd want - enabling him to kill the host.
--
Sasha.
next reply other threads:[~2011-11-20 15:00 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-20 14:58 Sasha Levin [this message]
2011-11-20 15:15 ` KVM device assignment and user privileges Avi Kivity
2011-11-21 4:42 ` Chris Wright
2011-11-21 8:32 ` Avi Kivity
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