Commit message: None
CVE: CVE-2011-4347
CWE: CWE-264
Vulnerability description: The kvm_vm_ioctl_assign_device function in virt/kvm/assigned-dev.c in the KVM subsystem in the Linux kernel before 3.1.10 does not verify permission to access PCI configuration space and BAR resources, which allows host OS users to assign PCI devices and cause a denial of service (host OS crash) via a KVM_ASSIGN_PCI_DEVICE operation.

Project: linux

static int assign_guest_irq(struct kvm *kvm,
			    struct kvm_assigned_dev_kernel *dev,
			    struct kvm_assigned_irq *irq,
			    unsigned long guest_irq_type)
{
	int id;
	int r = -EEXIST;

	if (dev->irq_requested_type & KVM_DEV_IRQ_GUEST_MASK)
		return r;

	id = kvm_request_irq_source_id(kvm);
	if (id < 0)
		return id;

	dev->irq_source_id = id;

	switch (guest_irq_type) {
	case KVM_DEV_IRQ_GUEST_INTX:
		r = assigned_device_enable_guest_intx(kvm, dev, irq);
		break;
#ifdef __KVM_HAVE_MSI
	case KVM_DEV_IRQ_GUEST_MSI:
		r = assigned_device_enable_guest_msi(kvm, dev, irq);
		break;
#endif
#ifdef __KVM_HAVE_MSIX
	case KVM_DEV_IRQ_GUEST_MSIX:
		r = assigned_device_enable_guest_msix(kvm, dev, irq);
		break;
#endif
	default:
		r = -EINVAL;
	}

	if (!r) {
		dev->irq_requested_type |= guest_irq_type;
		kvm_register_irq_ack_notifier(kvm, &dev->ack_notifier);
	} else
		kvm_free_irq_source_id(kvm, dev->irq_source_id);

	return r;
}

Project: linux

static int assign_host_irq(struct kvm *kvm,
			   struct kvm_assigned_dev_kernel *dev,
			   __u32 host_irq_type)
{
	int r = -EEXIST;

	if (dev->irq_requested_type & KVM_DEV_IRQ_HOST_MASK)
		return r;

	snprintf(dev->irq_name, sizeof(dev->irq_name), "kvm:%s",
		 pci_name(dev->dev));

	switch (host_irq_type) {
	case KVM_DEV_IRQ_HOST_INTX:
		r = assigned_device_enable_host_intx(kvm, dev);
		break;
#ifdef __KVM_HAVE_MSI
	case KVM_DEV_IRQ_HOST_MSI:
		r = assigned_device_enable_host_msi(kvm, dev);
		break;
#endif
#ifdef __KVM_HAVE_MSIX
	case KVM_DEV_IRQ_HOST_MSIX:
		r = assigned_device_enable_host_msix(kvm, dev);
		break;
#endif
	default:
		r = -EINVAL;
	}

	if (!r)
		dev->irq_requested_type |= host_irq_type;

	return r;
}

Project: linux

static int assigned_device_enable_guest_intx(struct kvm *kvm,
				struct kvm_assigned_dev_kernel *dev,
				struct kvm_assigned_irq *irq)
{
	dev->guest_irq = irq->guest_irq;
	dev->ack_notifier.gsi = irq->guest_irq;
	return 0;
}

Project: linux

static int assigned_device_enable_guest_msi(struct kvm *kvm,
			struct kvm_assigned_dev_kernel *dev,
			struct kvm_assigned_irq *irq)
{
	dev->guest_irq = irq->guest_irq;
	dev->ack_notifier.gsi = -1;
	dev->host_irq_disabled = false;
	return 0;
}

Project: linux

static int assigned_device_enable_guest_msix(struct kvm *kvm,
			struct kvm_assigned_dev_kernel *dev,
			struct kvm_assigned_irq *irq)
{
	dev->guest_irq = irq->guest_irq;
	dev->ack_notifier.gsi = -1;
	dev->host_irq_disabled = false;
	return 0;
}

Project: linux

static int assigned_device_enable_host_intx(struct kvm *kvm,
					    struct kvm_assigned_dev_kernel *dev)
{
	dev->host_irq = dev->dev->irq;
	/* Even though this is PCI, we don't want to use shared
	 * interrupts. Sharing host devices with guest-assigned devices
	 * on the same interrupt line is not a happy situation: there
	 * are going to be long delays in accepting, acking, etc.
	 */
	if (request_threaded_irq(dev->host_irq, NULL, kvm_assigned_dev_thread,
				 IRQF_ONESHOT, dev->irq_name, (void *)dev))
		return -EIO;
	return 0;
}

Project: linux

static int assigned_device_enable_host_msi(struct kvm *kvm,
					   struct kvm_assigned_dev_kernel *dev)
{
	int r;

	if (!dev->dev->msi_enabled) {
		r = pci_enable_msi(dev->dev);
		if (r)
			return r;
	}

	dev->host_irq = dev->dev->irq;
	if (request_threaded_irq(dev->host_irq, NULL, kvm_assigned_dev_thread,
				 0, dev->irq_name, (void *)dev)) {
		pci_disable_msi(dev->dev);
		return -EIO;
	}

	return 0;
}

Project: linux

static int assigned_device_enable_host_msix(struct kvm *kvm,
					    struct kvm_assigned_dev_kernel *dev)
{
	int i, r = -EINVAL;

	/* host_msix_entries and guest_msix_entries should have been
	 * initialized */
	if (dev->entries_nr == 0)
		return r;

	r = pci_enable_msix(dev->dev, dev->host_msix_entries, dev->entries_nr);
	if (r)
		return r;

	for (i = 0; i < dev->entries_nr; i++) {
		r = request_threaded_irq(dev->host_msix_entries[i].vector,
					 NULL, kvm_assigned_dev_thread,
					 0, dev->irq_name, (void *)dev);
		if (r)
			goto err;
	}

	return 0;
err:
	for (i -= 1; i >= 0; i--)
		free_irq(dev->host_msix_entries[i].vector, (void *)dev);
	pci_disable_msix(dev->dev);
	return r;
}

Project: linux

static void deassign_guest_irq(struct kvm *kvm,
			       struct kvm_assigned_dev_kernel *assigned_dev)
{
	kvm_unregister_irq_ack_notifier(kvm, &assigned_dev->ack_notifier);
	assigned_dev->ack_notifier.gsi = -1;

	kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id,
		    assigned_dev->guest_irq, 0);

	if (assigned_dev->irq_source_id != -1)
		kvm_free_irq_source_id(kvm, assigned_dev->irq_source_id);
	assigned_dev->irq_source_id = -1;
	assigned_dev->irq_requested_type &= ~(KVM_DEV_IRQ_GUEST_MASK);
}

Project: linux

static void deassign_host_irq(struct kvm *kvm,
			      struct kvm_assigned_dev_kernel *assigned_dev)
{
	/*
	 * We disable irq here to prevent further events.
	 *
	 * Notice this maybe result in nested disable if the interrupt type is
	 * INTx, but it's OK for we are going to free it.
	 *
	 * If this function is a part of VM destroy, please ensure that till
	 * now, the kvm state is still legal for probably we also have to wait
	 * on a currently running IRQ handler.
	 */
	if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSIX) {
		int i;
		for (i = 0; i < assigned_dev->entries_nr; i++)
			disable_irq(assigned_dev->host_msix_entries[i].vector);

		for (i = 0; i < assigned_dev->entries_nr; i++)
			free_irq(assigned_dev->host_msix_entries[i].vector,
				 (void *)assigned_dev);

		assigned_dev->entries_nr = 0;
		kfree(assigned_dev->host_msix_entries);
		kfree(assigned_dev->guest_msix_entries);
		pci_disable_msix(assigned_dev->dev);
	} else {
		/* Deal with MSI and INTx */
		disable_irq(assigned_dev->host_irq);

		free_irq(assigned_dev->host_irq, (void *)assigned_dev);

		if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSI)
			pci_disable_msi(assigned_dev->dev);
	}

	assigned_dev->irq_requested_type &= ~(KVM_DEV_IRQ_HOST_MASK);
}

Project: linux

static int find_index_from_host_irq(struct kvm_assigned_dev_kernel
				    *assigned_dev, int irq)
{
	int i, index;
	struct msix_entry *host_msix_entries;

	host_msix_entries = assigned_dev->host_msix_entries;

	index = -1;
	for (i = 0; i < assigned_dev->entries_nr; i++)
		if (irq == host_msix_entries[i].vector) {
			index = i;
			break;
		}
	if (index < 0) {
		printk(KERN_WARNING "Fail to find correlated MSI-X entry!\n");
		return 0;
	}

	return index;
}

Project: linux

static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian)
{
	struct kvm_assigned_dev_kernel *dev;

	if (kian->gsi == -1)
		return;

	dev = container_of(kian, struct kvm_assigned_dev_kernel,
			   ack_notifier);

	kvm_set_irq(dev->kvm, dev->irq_source_id, dev->guest_irq, 0);

	/* The guest irq may be shared so this ack may be
	 * from another device.
	 */
	spin_lock(&dev->intx_lock);
	if (dev->host_irq_disabled) {
		enable_irq(dev->host_irq);
		dev->host_irq_disabled = false;
	}
	spin_unlock(&dev->intx_lock);
}

Project: linux

static int kvm_deassign_irq(struct kvm *kvm,
			    struct kvm_assigned_dev_kernel *assigned_dev,
			    unsigned long irq_requested_type)
{
	unsigned long guest_irq_type, host_irq_type;

	if (!irqchip_in_kernel(kvm))
		return -EINVAL;
	/* no irq assignment to deassign */
	if (!assigned_dev->irq_requested_type)
		return -ENXIO;

	host_irq_type = irq_requested_type & KVM_DEV_IRQ_HOST_MASK;
	guest_irq_type = irq_requested_type & KVM_DEV_IRQ_GUEST_MASK;

	if (host_irq_type)
		deassign_host_irq(kvm, assigned_dev);
	if (guest_irq_type)
		deassign_guest_irq(kvm, assigned_dev);

	return 0;
}

Project: linux

 static struct kvm_assigned_dev_kernel *kvm_find_assigned_dev(struct list_head *head,
						      int assigned_dev_id)
{
	struct list_head *ptr;
	struct kvm_assigned_dev_kernel *match;

	list_for_each(ptr, head) {
		match = list_entry(ptr, struct kvm_assigned_dev_kernel, list);
		if (match->assigned_dev_id == assigned_dev_id)
			return match;
	}
	return NULL;
}

Project: linux

void kvm_free_all_assigned_devices(struct kvm *kvm)
{
	struct list_head *ptr, *ptr2;
	struct kvm_assigned_dev_kernel *assigned_dev;

	list_for_each_safe(ptr, ptr2, &kvm->arch.assigned_dev_head) {
		assigned_dev = list_entry(ptr,
					  struct kvm_assigned_dev_kernel,
					  list);

		kvm_free_assigned_device(kvm, assigned_dev);
	}
}

Project: linux

static void kvm_free_assigned_device(struct kvm *kvm,
				     struct kvm_assigned_dev_kernel
				     *assigned_dev)
{
	kvm_free_assigned_irq(kvm, assigned_dev);

	pci_reset_function(assigned_dev->dev);
	if (pci_load_and_free_saved_state(assigned_dev->dev,
					  &assigned_dev->pci_saved_state))
		printk(KERN_INFO "%s: Couldn't reload %s saved state\n",
		       __func__, dev_name(&assigned_dev->dev->dev));
	else
		pci_restore_state(assigned_dev->dev);

	pci_release_regions(assigned_dev->dev);
	pci_disable_device(assigned_dev->dev);
	pci_dev_put(assigned_dev->dev);

	list_del(&assigned_dev->list);
	kfree(assigned_dev);
}

Project: linux

static void kvm_free_assigned_irq(struct kvm *kvm,
				  struct kvm_assigned_dev_kernel *assigned_dev)
{
	kvm_deassign_irq(kvm, assigned_dev, assigned_dev->irq_requested_type);
}

Project: linux

static int kvm_vm_ioctl_assign_irq(struct kvm *kvm,
				   struct kvm_assigned_irq *assigned_irq)
{
	int r = -EINVAL;
	struct kvm_assigned_dev_kernel *match;
	unsigned long host_irq_type, guest_irq_type;

	if (!irqchip_in_kernel(kvm))
		return r;

	mutex_lock(&kvm->lock);
	r = -ENODEV;
	match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
				      assigned_irq->assigned_dev_id);
	if (!match)
		goto out;

	host_irq_type = (assigned_irq->flags & KVM_DEV_IRQ_HOST_MASK);
	guest_irq_type = (assigned_irq->flags & KVM_DEV_IRQ_GUEST_MASK);

	r = -EINVAL;
	/* can only assign one type at a time */
	if (hweight_long(host_irq_type) > 1)
		goto out;
	if (hweight_long(guest_irq_type) > 1)
		goto out;
	if (host_irq_type == 0 && guest_irq_type == 0)
		goto out;

	r = 0;
	if (host_irq_type)
		r = assign_host_irq(kvm, match, host_irq_type);
	if (r)
		goto out;

	if (guest_irq_type)
		r = assign_guest_irq(kvm, match, assigned_irq, guest_irq_type);
out:
	mutex_unlock(&kvm->lock);
	return r;
}

Project: linux

long kvm_vm_ioctl_assigned_device(struct kvm *kvm, unsigned ioctl,
				  unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int r;

	switch (ioctl) {
	case KVM_ASSIGN_PCI_DEVICE: {
		struct kvm_assigned_pci_dev assigned_dev;

		r = -EFAULT;
		if (copy_from_user(&assigned_dev, argp, sizeof assigned_dev))
			goto out;
		r = kvm_vm_ioctl_assign_device(kvm, &assigned_dev);
		if (r)
			goto out;
		break;
	}
	case KVM_ASSIGN_IRQ: {
		r = -EOPNOTSUPP;
		break;
	}
	case KVM_ASSIGN_DEV_IRQ: {
		struct kvm_assigned_irq assigned_irq;

		r = -EFAULT;
		if (copy_from_user(&assigned_irq, argp, sizeof assigned_irq))
			goto out;
		r = kvm_vm_ioctl_assign_irq(kvm, &assigned_irq);
		if (r)
			goto out;
		break;
	}
	case KVM_DEASSIGN_DEV_IRQ: {
		struct kvm_assigned_irq assigned_irq;

		r = -EFAULT;
		if (copy_from_user(&assigned_irq, argp, sizeof assigned_irq))
			goto out;
		r = kvm_vm_ioctl_deassign_dev_irq(kvm, &assigned_irq);
		if (r)
			goto out;
		break;
	}
	case KVM_DEASSIGN_PCI_DEVICE: {
		struct kvm_assigned_pci_dev assigned_dev;

		r = -EFAULT;
		if (copy_from_user(&assigned_dev, argp, sizeof assigned_dev))
			goto out;
		r = kvm_vm_ioctl_deassign_device(kvm, &assigned_dev);
		if (r)
			goto out;
		break;
	}
#ifdef KVM_CAP_IRQ_ROUTING
	case KVM_SET_GSI_ROUTING: {
		struct kvm_irq_routing routing;
		struct kvm_irq_routing __user *urouting;
		struct kvm_irq_routing_entry *entries;

		r = -EFAULT;
		if (copy_from_user(&routing, argp, sizeof(routing)))
			goto out;
		r = -EINVAL;
		if (routing.nr >= KVM_MAX_IRQ_ROUTES)
			goto out;
		if (routing.flags)
			goto out;
		r = -ENOMEM;
		entries = vmalloc(routing.nr * sizeof(*entries));
		if (!entries)
			goto out;
		r = -EFAULT;
		urouting = argp;
		if (copy_from_user(entries, urouting->entries,
				   routing.nr * sizeof(*entries)))
			goto out_free_irq_routing;
		r = kvm_set_irq_routing(kvm, entries, routing.nr,
					routing.flags);
	out_free_irq_routing:
		vfree(entries);
		break;
	}
#endif /* KVM_CAP_IRQ_ROUTING */
#ifdef __KVM_HAVE_MSIX
	case KVM_ASSIGN_SET_MSIX_NR: {
		struct kvm_assigned_msix_nr entry_nr;
		r = -EFAULT;
		if (copy_from_user(&entry_nr, argp, sizeof entry_nr))
			goto out;
		r = kvm_vm_ioctl_set_msix_nr(kvm, &entry_nr);
		if (r)
			goto out;
		break;
	}
	case KVM_ASSIGN_SET_MSIX_ENTRY: {
		struct kvm_assigned_msix_entry entry;
		r = -EFAULT;
		if (copy_from_user(&entry, argp, sizeof entry))
			goto out;
		r = kvm_vm_ioctl_set_msix_entry(kvm, &entry);
		if (r)
			goto out;
		break;
	}
#endif
	default:
		r = -ENOTTY;
		break;
	}
out:
	return r;
}

Project: linux

static int kvm_vm_ioctl_deassign_dev_irq(struct kvm *kvm,
					 struct kvm_assigned_irq
					 *assigned_irq)
{
	int r = -ENODEV;
	struct kvm_assigned_dev_kernel *match;

	mutex_lock(&kvm->lock);

	match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
				      assigned_irq->assigned_dev_id);
	if (!match)
		goto out;

	r = kvm_deassign_irq(kvm, match, assigned_irq->flags);
out:
	mutex_unlock(&kvm->lock);
 	return r;
 }

Project: linux

static int kvm_vm_ioctl_deassign_device(struct kvm *kvm,
		struct kvm_assigned_pci_dev *assigned_dev)
{
	int r = 0;
	struct kvm_assigned_dev_kernel *match;

	mutex_lock(&kvm->lock);

	match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
				      assigned_dev->assigned_dev_id);
	if (!match) {
		printk(KERN_INFO "%s: device hasn't been assigned before, "
		  "so cannot be deassigned\n", __func__);
		r = -EINVAL;
		goto out;
	}

	kvm_deassign_device(kvm, match);

	kvm_free_assigned_device(kvm, match);

out:
	mutex_unlock(&kvm->lock);
	return r;
}

Project: linux

static int kvm_vm_ioctl_set_msix_entry(struct kvm *kvm,
				       struct kvm_assigned_msix_entry *entry)
{
	int r = 0, i;
	struct kvm_assigned_dev_kernel *adev;

	mutex_lock(&kvm->lock);

	adev = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
				      entry->assigned_dev_id);

	if (!adev) {
		r = -EINVAL;
		goto msix_entry_out;
	}

	for (i = 0; i < adev->entries_nr; i++)
		if (adev->guest_msix_entries[i].vector == 0 ||
		    adev->guest_msix_entries[i].entry == entry->entry) {
			adev->guest_msix_entries[i].entry = entry->entry;
			adev->guest_msix_entries[i].vector = entry->gsi;
			adev->host_msix_entries[i].entry = entry->entry;
			break;
		}
	if (i == adev->entries_nr) {
		r = -ENOSPC;
		goto msix_entry_out;
	}

msix_entry_out:
	mutex_unlock(&kvm->lock);

	return r;
}

Project: linux

static int kvm_vm_ioctl_set_msix_nr(struct kvm *kvm,
				    struct kvm_assigned_msix_nr *entry_nr)
{
	int r = 0;
	struct kvm_assigned_dev_kernel *adev;

	mutex_lock(&kvm->lock);

	adev = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
				      entry_nr->assigned_dev_id);
	if (!adev) {
		r = -EINVAL;
		goto msix_nr_out;
	}

	if (adev->entries_nr == 0) {
		adev->entries_nr = entry_nr->entry_nr;
		if (adev->entries_nr == 0 ||
		    adev->entries_nr > KVM_MAX_MSIX_PER_DEV) {
			r = -EINVAL;
			goto msix_nr_out;
		}

		adev->host_msix_entries = kzalloc(sizeof(struct msix_entry) *
						entry_nr->entry_nr,
						GFP_KERNEL);
		if (!adev->host_msix_entries) {
			r = -ENOMEM;
			goto msix_nr_out;
		}
		adev->guest_msix_entries =
			kzalloc(sizeof(struct msix_entry) * entry_nr->entry_nr,
				GFP_KERNEL);
		if (!adev->guest_msix_entries) {
			kfree(adev->host_msix_entries);
			r = -ENOMEM;
			goto msix_nr_out;
		}
	} else /* Not allowed set MSI-X number twice */
		r = -EINVAL;
msix_nr_out:
	mutex_unlock(&kvm->lock);
	return r;
}