From: Yosry Ahmed Date: Tue, 3 Mar 2026 00:34:02 +0000 (+0000) Subject: KVM: nSVM: Triple fault if mapping VMCB12 fails on nested #VMEXIT X-Git-Tag: v7.1-rc1~118^2~4^2~46 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=1b30e7551767cb95b3e49bb169c72bbd76b56e05;p=thirdparty%2Flinux.git KVM: nSVM: Triple fault if mapping VMCB12 fails on nested #VMEXIT KVM currently injects a #GP and hopes for the best if mapping VMCB12 fails on nested #VMEXIT, and only if the failure mode is -EINVAL. Mapping the VMCB12 could also fail if creating host mappings fails. After the #GP is injected, nested_svm_vmexit() bails early, without cleaning up (e.g. KVM_REQ_GET_NESTED_STATE_PAGES is set, is_guest_mode() is true, etc). Instead of optionally injecting a #GP, triple fault the guest if mapping VMCB12 fails since KVM cannot make a sane recovery. The APM states that a #VMEXIT will triple fault if host state is illegal or an exception occurs while loading host state, so the behavior is not entirely made up. Do not return early from nested_svm_vmexit(), continue cleaning up the vCPU state (e.g. switch back to vmcb01), to handle the failure as gracefully as possible. Fixes: cf74a78b229d ("KVM: SVM: Add VMEXIT handler and intercepts") CC: stable@vger.kernel.org Co-developed-by: Sean Christopherson Signed-off-by: Yosry Ahmed Link: https://patch.msgid.link/20260303003421.2185681-9-yosry@kernel.org Signed-off-by: Sean Christopherson --- diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 8c01916cb1549..30c99bbe9927d 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -1199,12 +1199,8 @@ int nested_svm_vmexit(struct vcpu_svm *svm) struct vmcb *vmcb02 = svm->nested.vmcb02.ptr; int rc; - rc = nested_svm_vmexit_update_vmcb12(vcpu); - if (rc) { - if (rc == -EINVAL) - kvm_inject_gp(vcpu, 0); - return 1; - } + if (nested_svm_vmexit_update_vmcb12(vcpu)) + kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu); /* Exit Guest-Mode */ leave_guest_mode(vcpu);