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CVE-2026-23425

In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Fix ID register initialization for non-protected pKVM guests In protected mode, the hyp…

Published Apr 3, 2026 · updated Jul 21, 2026 · linux linux kernel

In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Fix ID register initialization for non-protected pKVM guests In protected mode, the hypervisor maintains a separate instance of the structure for each VM. For non-protected VMs, this structure is initialized from the host's state. Currently, copies the flag from the host without the underlying data being initialized. This results in the hypervisor seeing the flag as set while the ID registers remain zeroed. Consequently, checks at EL2 fail (return 0) for non-protected VMs. This breaks logic that relies on feature detection, such as for TCR2_EL1 support. As a result, certain system registers (e.g., TCR2_EL1, PIR_EL1, POR_EL1) are not saved/restored during the world switch, which could lead to state corruption. Fix this by explicitly copying the ID registers from the host to the hypervisor for non-protected VMs during initialization, since we trust the host with its non-protected guests' features. Also ensure is cleared initially in so that can properly initialize them and set the flag once done.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Apr 3, 2026 · NIST NVD

    Detected

    In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Fix ID register initialization for non-protected pKVM guests In protected mode, the hypervisor maintains a separate instance of the structure for each VM. For non-protected VMs, this structure is initialized from the host's state. Currently, copies the flag from the host without the underlying data being initialized. T

  2. Jul 21, 2026 · NIST NVD

    Updated

    In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Fix ID register initialization for non-protected pKVM guests In protected mode, the hypervisor maintains a separate instance of the structure for each VM. For non-protected VMs, this structure is initialized from the host's state. Currently, copies the flag from the host without the underlying data being initialized. T

Affected

  • cpe linux/linux kernelversion unspecified
  • cpe linux/linux kernel6.14
  • cpe linux/linux kernel7.0

Sources

  • CVE.orgVulnerability recordCVE-2026-23425

    Official CVE identifier

    cve.org
  • NIST NVDVulnerability recordCVE-2026-23425

    In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Fix ID register initialization for non-protected pKVM guests In protected mode, the hypervisor maintains a separate instance of the structure for each VM. For non-protected VMs, this structure

    nvd.nist.gov

References