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Re: [Qemu-devel] [PATCH 0/5] ATAPI pass through v2
From: |
Anthony Liguori |
Subject: |
Re: [Qemu-devel] [PATCH 0/5] ATAPI pass through v2 |
Date: |
Wed, 08 Jul 2009 12:20:59 -0500 |
User-agent: |
Thunderbird 2.0.0.21 (X11/20090320) |
Ian Jackson wrote:
Anthony Liguori writes ("Re: [Qemu-devel] [PATCH 0/5] ATAPI pass through v2"):
No need for a switch IMHO. If a user is doing pass through, they ought
to expect that the guest has direct access to the device.
The firmware of an IDE device can usually take over complete the
control of the host, if it chooses to and knows how. So upgrading the
firmware on the device is a lot more serious than just being able to
break the device. It would allow the guest to escape containment.
So this definitely needs to be disabled by default.
Pass through == escape containment.
That's generally true (even with VT-d). There's all sorts of bad things
you can do generating interrupt storms or physically bricking hardware.
I disagree entirely. The qemu process inevitably has access to an
enormous amount of stuff that the guest shouldn't have, and in most
cases users don't even run it as a different user.
Or are you suggesting qemu should always be run in a chroot ?
As a lesser privileged user or as root heavily restricted by SELinux, yes.
Or a VM
perhaps ? qemu only safe run under Xen PV ? I don't think the KVM
guys are really going to like that as a security policy ...
It's about layers of security. If you design your security assuming
that QEMU is safe, you're taking a much bigger risk than if you assume
QEMU is hostile.
I'm sure something like SELinux can be used to prevent a root QEMU
process from doing a firmware upgrade.
*boggle* You're not serious, are you ?
Yes, I'm actually a fan of SELinux in the context of a dedicated
virtualization system.
Regards,
Anthony Liguori
- Re: [Qemu-devel] [PATCH 0/5] ATAPI pass through v2, (continued)
- Re: [Qemu-devel] [PATCH 0/5] ATAPI pass through v2, Alexandre Bique, 2009/07/07
- Re: [Qemu-devel] [PATCH 0/5] ATAPI pass through v2, Paul Brook, 2009/07/07
- Re: [Qemu-devel] [PATCH 0/5] ATAPI pass through v2, Alexandre Bique, 2009/07/07
- Re: [Qemu-devel] [PATCH 0/5] ATAPI pass through v2, Anthony Liguori, 2009/07/07
- Re: [Qemu-devel] [PATCH 0/5] ATAPI pass through v2, Stuart Brady, 2009/07/07
- Re: [Qemu-devel] [PATCH 0/5] ATAPI pass through v2, Ian Jackson, 2009/07/08
- Re: [Qemu-devel] [PATCH 0/5] ATAPI pass through v2, Avi Kivity, 2009/07/08
- Re: [Qemu-devel] [PATCH 0/5] ATAPI pass through v2, Carl-Daniel Hailfinger, 2009/07/08
- Re: [Qemu-devel] [PATCH 0/5] ATAPI pass through v2, Anthony Liguori, 2009/07/08
- Re: [Qemu-devel] [PATCH 0/5] ATAPI pass through v2, Avi Kivity, 2009/07/08
- Re: [Qemu-devel] [PATCH 0/5] ATAPI pass through v2,
Anthony Liguori <=
- Re: [Qemu-devel] [PATCH 0/5] ATAPI pass through v2, Vincent Hanquez, 2009/07/08
- Re: [Qemu-devel] [PATCH 0/5] ATAPI pass through v2, Anthony Liguori, 2009/07/08
Re: [Qemu-devel] [PATCH 0/5] ATAPI pass through v2, Anthony Liguori, 2009/07/07