Bug 2406737 (CVE-2025-40065)

Summary: CVE-2025-40065 kernel: RISC-V: KVM: Write hgatp register with valid mode bits
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Version: unspecifiedKeywords: Security
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OS: Linux   
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Description OSIDB Bzimport 2025-10-28 12:02:51 UTC 
In the Linux kernel, the following vulnerability has been resolved:

RISC-V: KVM: Write hgatp register with valid mode bits

According to the RISC-V Privileged Architecture Spec, when MODE=Bare
is selected,software must write zero to the remaining fields of hgatp.

We have detected the valid mode supported by the HW before, So using a
valid mode to detect how many vmid bits are supported.
Comment 1 Jon Moroney 2025-10-28 19:12:50 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025102817-CVE-2025-40065-7740@gregkh/T