From: Sean Christopherson seanjc@google.com
[ Upstream commit 053d2290c0307e3642e75e0185ddadf084dc36c1 ]
Exit to userspace with an emulation error if KVM encounters an injected exception with invalid guest state, in addition to the existing check of bailing if there's a pending exception (KVM doesn't support emulating exceptions except when emulating real mode via vm86).
In theory, KVM should never get to such a situation as KVM is supposed to exit to userspace before injecting an exception with invalid guest state. But in practice, userspace can intervene and manually inject an exception and/or stuff registers to force invalid guest state while a previously injected exception is awaiting reinjection.
Fixes: fc4fad79fc3d ("KVM: VMX: Reject KVM_RUN if emulation is required with pending exception") Reported-by: syzbot+cfafed3bb76d3e37581b@syzkaller.appspotmail.com Signed-off-by: Sean Christopherson seanjc@google.com Message-Id: 20220502221850.131873-1-seanjc@google.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/kvm/vmx/vmx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index ef63cfd57029..267d6dc4b818 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -5473,7 +5473,7 @@ static bool vmx_emulation_required_with_pending_exception(struct kvm_vcpu *vcpu) struct vcpu_vmx *vmx = to_vmx(vcpu);
return vmx->emulation_required && !vmx->rmode.vm86_active && - vcpu->arch.exception.pending; + (vcpu->arch.exception.pending || vcpu->arch.exception.injected); }
static int handle_invalid_guest_state(struct kvm_vcpu *vcpu)