Commit caa98440 authored by Bjorn Helgaas's avatar Bjorn Helgaas
Browse files

Merge branch 'remotes/lorenzo/pci/hv'

  - Fix Hyper-V use-after-free in eject path (Dexuan Cui)

* remotes/lorenzo/pci/hv:
  PCI: hv: Fix a use-after-free bug in hv_eject_device_work()
parents 6c90132f 4df591b2
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+9 −6
Original line number Diff line number Diff line
@@ -1875,6 +1875,7 @@ static void hv_pci_devices_present(struct hv_pcibus_device *hbus,
static void hv_eject_device_work(struct work_struct *work)
{
	struct pci_eject_response *ejct_pkt;
	struct hv_pcibus_device *hbus;
	struct hv_pci_dev *hpdev;
	struct pci_dev *pdev;
	unsigned long flags;
@@ -1885,6 +1886,7 @@ static void hv_eject_device_work(struct work_struct *work)
	} ctxt;

	hpdev = container_of(work, struct hv_pci_dev, wrk);
	hbus = hpdev->hbus;

	WARN_ON(hpdev->state != hv_pcichild_ejecting);

@@ -1895,8 +1897,7 @@ static void hv_eject_device_work(struct work_struct *work)
	 * because hbus->pci_bus may not exist yet.
	 */
	wslot = wslot_to_devfn(hpdev->desc.win_slot.slot);
	pdev = pci_get_domain_bus_and_slot(hpdev->hbus->sysdata.domain, 0,
					   wslot);
	pdev = pci_get_domain_bus_and_slot(hbus->sysdata.domain, 0, wslot);
	if (pdev) {
		pci_lock_rescan_remove();
		pci_stop_and_remove_bus_device(pdev);
@@ -1904,9 +1905,9 @@ static void hv_eject_device_work(struct work_struct *work)
		pci_unlock_rescan_remove();
	}

	spin_lock_irqsave(&hpdev->hbus->device_list_lock, flags);
	spin_lock_irqsave(&hbus->device_list_lock, flags);
	list_del(&hpdev->list_entry);
	spin_unlock_irqrestore(&hpdev->hbus->device_list_lock, flags);
	spin_unlock_irqrestore(&hbus->device_list_lock, flags);

	if (hpdev->pci_slot)
		pci_destroy_slot(hpdev->pci_slot);
@@ -1915,7 +1916,7 @@ static void hv_eject_device_work(struct work_struct *work)
	ejct_pkt = (struct pci_eject_response *)&ctxt.pkt.message;
	ejct_pkt->message_type.type = PCI_EJECTION_COMPLETE;
	ejct_pkt->wslot.slot = hpdev->desc.win_slot.slot;
	vmbus_sendpacket(hpdev->hbus->hdev->channel, ejct_pkt,
	vmbus_sendpacket(hbus->hdev->channel, ejct_pkt,
			 sizeof(*ejct_pkt), (unsigned long)&ctxt.pkt,
			 VM_PKT_DATA_INBAND, 0);

@@ -1924,7 +1925,9 @@ static void hv_eject_device_work(struct work_struct *work)
	/* For the two refs got in new_pcichild_device() */
	put_pcichild(hpdev);
	put_pcichild(hpdev);
	put_hvpcibus(hpdev->hbus);
	/* hpdev has been freed. Do not use it any more. */

	put_hvpcibus(hbus);
}

/**