From: Vitaly Kuznetsov vkuznets@redhat.com
commit 7ec37d1cbe17d8189d9562178d8b29167fe1c31a upstream.
When KVM_CAP_HYPERV_SYNIC{,2} is activated, KVM already checks for irqchip_in_kernel() so normally SynIC irqs should never be set. It is, however, possible for a misbehaving VMM to write to SYNIC/STIMER MSRs causing erroneous behavior.
The immediate issue being fixed is that kvm_irq_delivery_to_apic() (kvm_irq_delivery_to_apic_fast()) crashes when called with 'irq.shorthand = APIC_DEST_SELF' and 'src == NULL'.
Signed-off-by: Vitaly Kuznetsov vkuznets@redhat.com Message-Id: 20220325132140.25650-2-vkuznets@redhat.com Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kvm/hyperv.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -446,6 +446,9 @@ static int synic_set_irq(struct kvm_vcpu struct kvm_lapic_irq irq; int ret, vector;
+ if (KVM_BUG_ON(!lapic_in_kernel(vcpu), vcpu->kvm)) + return -EINVAL; + if (sint >= ARRAY_SIZE(synic->sint)) return -EINVAL;