So you might really want to make sure VirtualBox issues a fix for this before 5.18, as it's arguably security sensitive. As soon as I move the trackpoint around, the below program prints 'XSAVE is borked!'.Īlso, note that this isn't just 'corruption' of the guest VM, but also leaking secret contents of the host VM into the guest. On my laptop, for example, the trackpoint goes via hardirq, but the touchpad does not. Run this in a VirtualBox VM, and then move your mouse around or hit the keyboard, or do something that triggers the add_randomness() path from a hardirq handler. I wrote a tiny reproducer that should be pretty reliable for testing this, attached below.

xGvOuwouHO- Edge Security May 18, 2022ĭonenfeld explained on the kernel mailing list: On 5.18 this takes the form of secret intermediate cryptographic hash values leaking into the guest. If SIMD registers are used in interrupt handlers, apparently #VirtualBox will leak host register secret values into arbitrary guest VM processes. When SIMD registers are used within interrupt handlers, it's possible for VirtualBox to leak data from the host to guest VMs.

Security researcher Jason Donenfeld who is known for leading the development of the WireGuard open-source software has outlined a new security vulnerability affecting the Oracle VM VirtualBox software.

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