KVM: Take missing slots_lock for kvm_io_bus_unregister_dev()

In KVM_CREATE_IRQCHIP, kvm_io_bus_unregister_dev() is called without taking
slots_lock in the error handling path.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index cbaea7dd5963..f569da8ff839 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3309,8 +3309,10 @@ long kvm_arch_vm_ioctl(struct file *filp,
                 if (vpic) {
                         r = kvm_ioapic_init(kvm);
                         if (r) {
+                                mutex_lock(&kvm->slots_lock);
                                 kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS,
                                                           &vpic->dev);
+                                mutex_unlock(&kvm->slots_lock);
                                 kfree(vpic);
                                 goto create_irqchip_unlock;
                         }
@@ -3321,10 +3323,12 @@ long kvm_arch_vm_ioctl(struct file *filp,
                 smp_wmb();
                 r = kvm_setup_default_irq_routing(kvm);
                 if (r) {
+                        mutex_lock(&kvm->slots_lock);
                         mutex_lock(&kvm->irq_lock);
                         kvm_ioapic_destroy(kvm);
                         kvm_destroy_pic(kvm);
                         mutex_unlock(&kvm->irq_lock);
+                        mutex_unlock(&kvm->slots_lock);
                 }
         create_irqchip_unlock:
                 mutex_unlock(&kvm->lock);