Is it possible that javascript from a specific website, or a subset of websites could cause a Tor Browser crash, which then crashes the entire Xen hypervisor? Is there such a javascript attack?
Rowhammer possibly?
Wow! That would be the first ever recorded side channel attack, and the right to the heart of Qubes.
How is that a side channel? It is right at the application layer.
Wouldn’t a side channel attack be at a lower layer of the OSI model?
I don’t see how any app crashing could cause a Xen compromise.
Please note discussion of Whonix / Tor Browser is off topic here.
Discussions of possible Xen exploits are technically on topic but only if conducted with knowledge and evidence.
“just asking questions” without having details and evidence is FUD and won’t be tolerated.
The crash log seems to show a hypercall to the hypervisor, references xen-blkback which is a virtual block device. It references systemd and entropy. Insufficient entropy?
It seems like the hypercall is trying to read data, maybe from a virtual block device like a hard drive for example.
“random:systemd: uninitialized urandom read” → This is one of the lines in the error log.
This may be an issue with seeding the entropy pool with enough entropy. But I don’t know how to solve the issue.
Is Xen trying to read/write data to the hard drive? to RAM? Why is there insufficient entropy?
If you’d spend 30 seconds using a search engine of your choice you’d have discovered this is a know systemd bug along with the issue discussion around it.
What’s your motivation? Do you think you’ve been compromised? Why? What evidence is there that the compromise (if real) escaped that qube?
Until now all you’ve convinced me of is that your Tor Browser crashed, you saw log entries you don’t understand and you haven’t tried researching them to find out.
Why I react this way? Because what you are doing is the same thing as someone going to their doctor asking if they could have a rare and deadly disease because they woke up “not feeling right”.
Not every crash is evidence of a potential compromise.