[PATCH 5.15 065/917] KVM: VMX: Unregister posted interrupt wakeup handler on hardware unsetup

Greg Kroah-Hartman
2021-11-15T23:29:12Z

From: Sean Christopherson <seanjc@google.com>

commit ec5a4919fa7b7d8c7a2af1c7e799b1fe4be84343 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/kvm/vmx/vmx.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7551,6 +7551,8 @@ static void vmx_migrate_timers(struct kv

static void hardware_unsetup(void)
{
+ kvm_set_posted_intr_wakeup_handler(NULL);
+
if (nested)
nested_vmx_hardware_unsetup();

@@ -7879,8 +7881,6 @@ 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)
@@ -7904,6 +7904,9 @@ 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;
}