Last updated 24 July 2024
If the guest writes a noncanonical value to certain MSR registers, KVM will write that value to the MSR in the host context and a #GP will be raised leading to kernel panic.
A privileged guest user can use this flaw to crash the host.
Enabling CONFIGPARAVIRT when building the kernel mitigates this issue because wrmsrl() ends up invoking safe msr write variant.
Acknowledgements:
Red Hat would like to thank Lars Bull of Google and Nadav Amit for reporting this issue.
Last updated 24 July 2024