KVM: VMX: Unregister posted interrupt wakeup handler on hardware unsetup

Unregister KVM's posted interrupt wakeup handler during unsetup so that a
spurious interrupt that arrives after kvm_intel.ko is unloaded doesn't
call into freed memory.

Fixes: bf9f6ac8d749 ("KVM: Update Posted-Interrupts Descriptor when vCPU is blocked")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211009001107.3936588-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 2f677e72d864805ad0c6eb1397ed971e24878c41..c11688f64e80c64a25d35ca4d778fc4a2b3d71d2 100644 (file)
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7555,6 +7555,8 @@ static void vmx_migrate_timers(struct kvm_vcpu *vcpu)
 
 static void hardware_unsetup(void)
 {
+       kvm_set_posted_intr_wakeup_handler(NULL);
+
        if (nested)
                nested_vmx_hardware_unsetup();
 
@@ -7885,8 +7887,6 @@ static __init int hardware_setup(void)
                vmx_x86_ops.request_immediate_exit = __kvm_request_immediate_exit;
        }
 
-       kvm_set_posted_intr_wakeup_handler(pi_wakeup_handler);
-
        kvm_mce_cap_supported |= MCG_LMCE_P;
 
        if (pt_mode != PT_MODE_SYSTEM && pt_mode != PT_MODE_HOST_GUEST)
@@ -7910,6 +7910,9 @@ static __init int hardware_setup(void)
        r = alloc_kvm_area();
        if (r)
                nested_vmx_hardware_unsetup();
+
+       kvm_set_posted_intr_wakeup_handler(pi_wakeup_handler);
+
        return r;
 }