[PATCH v2 0/2] KVM: x86: Ensure userspace can't run L2 with stale PFNs

From: Sean Christopherson

Date: Mon Sep 21 2026 - 17:22:34 EST


Fix a class of bugs where KVM (a) lets userspace run L2 with potentially stale
PFNs and (b) fails to set kvm_run appropriately and so could unintentionally
cause a well-behaved VMM to run afoul of (a).

v2:
- Re-pend KVM_REQ_GET_NESTED_STATE_PAGES in the common vcpu_enter_guest()
path.
- Fix the kvm_run bug(s).

v1: https://lore.kernel.org/all/20260813043932.3214460-1-rkskek9254@xxxxxxxxx

Sean Christopherson (2):
KVM: x86: Re-pend GET_NESTED_STATE_PAGES if getting said pages fails
KVM: x86: Fill kvm_run exit fields in common get_nested_state_pages()
error paths

arch/x86/kvm/svm/nested.c | 7 +------
arch/x86/kvm/vmx/nested.c | 15 +++++----------
arch/x86/kvm/x86.c | 4 ++++
3 files changed, 10 insertions(+), 16 deletions(-)


base-commit: 70c944caf570fda2d79baa71435589a8db39f048
--
2.55.0.1082.g2b9226bbc0-goog