Patch "KVM: x86: fix user triggerable warning in kvm_apic_accept_events()" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

KVM: x86: fix user triggerable warning in kvm_apic_accept_events()

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
kvm-x86-fix-user-triggerable-warning-in-kvm_apic_accept_events.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: David Hildenbrand <[email protected]>
Date: Thu, 23 Mar 2017 11:46:03 +0100
Subject: KVM: x86: fix user triggerable warning in kvm_apic_accept_events()
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From: David Hildenbrand <[email protected]>

commit 28bf28887976d8881a3a59491896c718fade7355 upstream.

If we already entered/are about to enter SMM, don't allow switching to INIT/SIPI_RECEIVED, otherwise the next call to kvm_apic_accept_events() will report a warning.

Same applies if we are already in MP state INIT_RECEIVED and SMM is requested to be turned on. Refuse to set the VCPU events in this case.

---
 arch/x86/kvm/x86.c |   12 ++++++++++++
 1 file changed, 12 insertions(+)

@@ -3051,6 +3051,12 @@ static int kvm_vcpu_ioctl_x86_set_vcpu_e
 	    (events->exception.nr > 31 || events->exception.nr == NMI_VECTOR))
 		return -EINVAL;
 
+	/* INITs are latched while in SMM */
+	if (events->flags & KVM_VCPUEVENT_VALID_SMM &&
+	    (events->smi.smm || events->smi.pending) &&
+	    vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED)
+		return -EINVAL;
+
 	process_nmi(vcpu);
 	vcpu->arch.exception.pending = events->exception.injected;
 	vcpu->arch.exception.nr = events->exception.nr;

@@ -7162,6 +7168,12 @@ int kvm_arch_vcpu_ioctl_set_mpstate(stru
 	    mp_state->mp_state != KVM_MP_STATE_RUNNABLE)
 		return -EINVAL;
 
+	/* INITs are latched while in SMM */
+	if ((is_smm(vcpu) || vcpu->arch.smi_pending) &&
+	    (mp_state->mp_state == KVM_MP_STATE_SIPI_RECEIVED ||
+	     mp_state->mp_state == KVM_MP_STATE_INIT_RECEIVED))
+		return -EINVAL;
+
 	if (mp_state->mp_state == KVM_MP_STATE_SIPI_RECEIVED) {
 		vcpu->arch.mp_state = KVM_MP_STATE_INIT_RECEIVED;
 		set_bit(KVM_APIC_SIPI, &vcpu->arch.apic->pending_events);

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/kvm-x86-fix-user-triggerable-warning-in-kvm_apic_accept_events.patch