usb: hcd: use managed device resources

Using managed device resources in usb_hcd_pci_probe() allows devm usage for
resource subranges, such as the mmio resource for the platform device
created to control host/device mode mux, which is a xhci extended
capability, and sits inside the xhci mmio region.

If managed device resources are not used then "parent" resource
is released before subrange at driver removal as .remove callback is
called before the devres list of resources for this device is walked
and released.

This has been observed with the xhci extended capability driver causing a
use-after-free which is now fixed.

An additional nice benefit is that error handling on driver initialisation
is simplified much.

Signed-off-by: Carsten Schmid <carsten_schmid@mentor.com>
Tested-by: Carsten Schmid <carsten_schmid@mentor.com>
Reviewed-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Fixes: fa31b3c ("xhci: Add Intel extended cap / otg phy mux handling")
Cc: <stable@vger.kernel.org> # v4.19+

Link: https://lore.kernel.org/r/1566569488679.31808@mentor.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/hcd-pci.c

@@ -216,17 +216,18 @@ int usb_hcd_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 		/* EHCI, OHCI */
 		hcd->rsrc_start = pci_resource_start(dev, 0);
 		hcd->rsrc_len = pci_resource_len(dev, 0);
-		if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len,
-				driver->description)) {
+		if (!devm_request_mem_region(&dev->dev, hcd->rsrc_start,
+				hcd->rsrc_len, driver->description)) {
 			dev_dbg(&dev->dev, "controller already in use\n");
 			retval = -EBUSY;
 			goto put_hcd;
 		}
-		hcd->regs = ioremap_nocache(hcd->rsrc_start, hcd->rsrc_len);
+		hcd->regs = devm_ioremap_nocache(&dev->dev, hcd->rsrc_start,
+				hcd->rsrc_len);
 		if (hcd->regs == NULL) {
 			dev_dbg(&dev->dev, "error mapping memory\n");
 			retval = -EFAULT;
-			goto release_mem_region;
+			goto put_hcd;
 		}
 
 	} else {
@@ -240,8 +241,8 @@ int usb_hcd_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 
 			hcd->rsrc_start = pci_resource_start(dev, region);
 			hcd->rsrc_len = pci_resource_len(dev, region);
-			if (request_region(hcd->rsrc_start, hcd->rsrc_len,
-					driver->description))
+			if (devm_request_region(&dev->dev, hcd->rsrc_start,
+					hcd->rsrc_len, driver->description))
 				break;
 		}
 		if (region == PCI_ROM_RESOURCE) {
@@ -275,20 +276,13 @@ int usb_hcd_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	}
 
 	if (retval != 0)
-		goto unmap_registers;
+		goto put_hcd;
 	device_wakeup_enable(hcd->self.controller);
 
 	if (pci_dev_run_wake(dev))
 		pm_runtime_put_noidle(&dev->dev);
 	return retval;
 
-unmap_registers:
-	if (driver->flags & HCD_MEMORY) {
-		iounmap(hcd->regs);
-release_mem_region:
-		release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
-	} else
-		release_region(hcd->rsrc_start, hcd->rsrc_len);
 put_hcd:
 	usb_put_hcd(hcd);
 disable_pci:
@@ -347,14 +341,6 @@ void usb_hcd_pci_remove(struct pci_dev *dev)
 		dev_set_drvdata(&dev->dev, NULL);
 		up_read(&companions_rwsem);
 	}
-
-	if (hcd->driver->flags & HCD_MEMORY) {
-		iounmap(hcd->regs);
-		release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
-	} else {
-		release_region(hcd->rsrc_start, hcd->rsrc_len);
-	}
-
 	usb_put_hcd(hcd);
 	pci_disable_device(dev);
 }