CVE-2026-64287

Summary

In the Linux kernel, the following vulnerability has been resolved:

KVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU

flush_hyp_vcpu() copies the host vGIC state into the hyp's private vCPU on every run. The vGIC list register save and restore use used_lrs as their loop bound and expect it to stay within the number of implemented list registers. While this is generally the case, flush_hyp_vcpu() copies vgic_v3 verbatim and does not enforce this, so a value provided by the host is used at EL2 to index vgic_lr[] and access ICH_LR<n>_EL2 (host -> EL2).

Fix by clamping used_lrs to the number of implemented list registers after the copy, as the trusted path already does in vgic_flush_lr_state(). The number of implemented list registers is constant after init, so it is replicated once from kvm_vgic_global_state.nr_lr into hyp_gicv3_nr_lr rather than read on every entry.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxbe66e67f175096f283c9d5614c4991fc9e7ed975 < 2c5e72b9fbf83fdfa724e9f1af0f418ccf8739b8affected
LinuxLinuxbe66e67f175096f283c9d5614c4991fc9e7ed975 < 9fa301d8298778dd799fa4dcf7a7f440715d146eaffected
LinuxLinuxbe66e67f175096f283c9d5614c4991fc9e7ed975 < c646431865f4b1a5b14067233fa27b11e05e0d46affected
LinuxLinuxbe66e67f175096f283c9d5614c4991fc9e7ed975 < 7fca3fcef81c713bc82a37bf741e0f28e6d04a6faffected
LinuxLinuxbe66e67f175096f283c9d5614c4991fc9e7ed975 < 8cc8bbbfab14c22c5551d0dd19b208a44b141c76affected
LinuxLinux6.2affected
LinuxLinux0 < 6.2unaffected
LinuxLinux6.6.145 <= 6.6.*unaffected
LinuxLinux6.12.97 <= 6.12.*unaffected
LinuxLinux6.18.40 <= 6.18.*unaffected
LinuxLinux7.1.4 <= 7.1.*unaffected
LinuxLinux7.2-rc1 <= *unaffected

Weaknesses

References