oss-sec mailing list archives
Re: Linux/QEMU issue
From: "Steven M. Christey" <coley () linus mitre org>
Date: Wed, 23 Dec 2009 17:21:14 -0500 (EST)
On Tue, 8 Dec 2009, Jamie Strandboge wrote:
The bug is really two parts though: the qemu issue which crashes the guest, and the guest kernel writing garbage to the virtio net backend.
There are three options for how to handle this: - create separate CVEs, one for QEMU and one for virtio net - create one CVE, concentrating on QEMU, with virtio net as an example - create one CVE, concentrating on virtio new, mentioning the impact on QEMUIn the discussion in http://patchwork.kernel.org/patch/56479/, I don't see any clear resolution about whether it's a security problem that qemu exits in situations other than an ACPI shutdown. I don't know qemu/kvm so I can't be sure; if qemu can support multiple hosts at the same time, and a crash in one host triggers a qemu crash/exit that affects all the hosts, then I would call this an issue in qemu. If there's an attack angle to prevent forensics analysis, then that might be a reasonable argument, too.
If virtio net (whatever that is) exhibits this behavior in "normal" non-VM situations, then it should get a CVE itself. But if it's closely tied to qemu, or to VMs in general, then I'm less certain.
VMs can stretch our older notions about threat models, and I suspect that's why this is difficult to handle.
- Steve
We decided to fix it as a security update in qemu since a remote attacker could DoS an Ubuntu 8.04 LTS guest, possibly leading to data corruption within the guest. 2.6.26 and later kernels should not be affected. Jamie -- Jamie Strandboge | http://www.canonical.com
Current thread:
- Linux/QEMU issue Jamie Strandboge (Dec 08)
- Re: Linux/QEMU issue Steven M. Christey (Dec 23)