diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index d9b7001227e3..d251b718bf53 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -107,6 +107,8 @@ EXPORT_SYMBOL_GPL(kvm_debugfs_dir); static int kvm_debugfs_num_entries; static const struct file_operations *stat_fops_per_vm[]; +static struct file_operations kvm_chardev_ops; + static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl, unsigned long arg); #ifdef CONFIG_KVM_COMPAT @@ -714,6 +716,16 @@ static struct kvm *kvm_create_vm(unsigned long type) preempt_notifier_inc(); + /* + * When the fd passed to this ioctl() is opened it pins the module, + * but try_module_get() also prevents getting a reference if the module + * is in MODULE_STATE_GOING (e.g. if someone ran "rmmod --wait"). + */ + if (!try_module_get(kvm_chardev_ops.owner)) { + r = -ENODEV; + goto out_err; + } + return kvm; out_err: @@ -798,6 +810,7 @@ static void kvm_destroy_vm(struct kvm *kvm) preempt_notifier_dec(); hardware_disable_all(); mmdrop(mm); + module_put(kvm_chardev_ops.owner); } void kvm_get_kvm(struct kvm *kvm)