X events going to wrong VM?

[Daniel Allcock]

Hello,

Something peculiar happens occasionally on my qubes 4.0 system. I run
claws-mail in one VM, and mousing over the message list shows tooltips
as intended (not very useful; they just repeat the text that is under
the mouse). As I mouse up or down, the old tooltip disappears and a new
one appears, as you would expect.

But sometimes this happens when another VM's window (say firefox)
is on top of the claws window, and all the mouse movement takes place
inside the window on top. Somehow claws seems
to be receiving X mouse-motion events meant for the other VM. Obviously
this looks like a violation of qube isolation.

The tooltip windows are properly colored.
So as I move the mouse, yellow-bordered tooltip windows appear and
disappear on top of a (say) red-bordered window that is on top of
a yellow-bordered claws window. Visually this is very strange.

I wish I knew how to reproduce this. It just seems to happen by itself
every few days. I have a vague memory of something similar
happening *once* with some app other than claws. But I forget the
details. Anyone else have this experience? Or thoughts about
what to try to maybe reproduce it more reliably?

Thanks,
Daniel

[Mike Keehan]

Hi Daniel,

I have the same problem on my system. Not only with Claws mailer, but
also with Firefox occasionally, and most often with an xfce panel that
runs in sys-net and shows me the weather and the network load.

The odd part is that the panel widgets display their popups even though
I never hover the mouse over them deliberately. The popups display
when I use the scrollwheel to switch desktops.

As you say, it is not easily reproducible, so debugging it will be hard
I expect.

Mike.

[Daniel Allcock]

Thanks Mike,

Your experience sounds even stranger than my own. I'm not sure
whether it is more worrying---it's not so bad if the panel can read VM's
events, since dom0 already reads all of them. But unexpected events
being sent to dom0 sounds like a way to make dom0 do things possibly
against user intent.

btw, you wouldn't be the Mike Keehan that I worked for in Summer 1991
at Shell?

Daniel

[Mike Keehan]

Hi Daniel,

I don't think it is events being sent to to dom0, but keyboard events
going to the VM. And then the app in the VM just displays the popup
as usual. So I do not think there is any security issue, but just a
bug somewhere in the event handling code.

Mike.

[Mike Keehan]

Argh, I meant mouse events, not keyboard.