usb/dummy_hcd: don't probe for udc if hcd failed

the_controller is allocated in dummy_hcd_probe() and is NULL if the
allocation failed. The probe function of the udc driver is dereferencing
this pointer and fault.
Alan Stern suggested to abort the dummy_hcd driver probing so the module
is not loaded. The is abort-on-error has been also added to the udc
driver.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 20 insertions, 1 deletions

diff --git a/drivers/usb/gadget/dummy_hcd.c b/drivers/usb/gadget/dummy_hcd.c
index 3214ca375d64..61ff927928ab 100644
--- a/drivers/usb/gadget/dummy_hcd.c
+++ b/drivers/usb/gadget/dummy_hcd.c
@@ -892,10 +892,11 @@ static int dummy_udc_probe (struct platform_device *pdev)
                 return rc;
         }
 
-        platform_set_drvdata (pdev, dum);
         rc = device_create_file (&dum->gadget.dev, &dev_attr_function);
         if (rc < 0)
                 device_unregister (&dum->gadget.dev);
+        else
+                platform_set_drvdata(pdev, dum);
         return rc;
 }
 
@@ -1995,11 +1996,29 @@ static int __init init (void)
         retval = platform_device_add(the_hcd_pdev);
         if (retval < 0)
                 goto err_add_hcd;
+        if (!the_controller) {
+                /*
+                 * The hcd was added successfully but its probe function failed
+                 * for some reason.
+                 */
+                retval = -EINVAL;
+                goto err_add_udc;
+        }
         retval = platform_device_add(the_udc_pdev);
         if (retval < 0)
                 goto err_add_udc;
+        if (!platform_get_drvdata(the_udc_pdev)) {
+                /*
+                 * The udc was added successfully but its probe function failed
+                 * for some reason.
+                 */
+                retval = -EINVAL;
+                goto err_probe_udc;
+        }
         return retval;
 
+err_probe_udc:
+        platform_device_del(the_udc_pdev);
 err_add_udc:
         platform_device_del(the_hcd_pdev);
 err_add_hcd: