USB: fix bugs in usb_(de)authorize_device

This patch (as1315) fixes some bugs in the USB core authorization
code:

	usb_deauthorize_device() should deallocate the device strings
	instead of leaking them, and it should invoke
	usb_destroy_configuration() (which does proper reference
	counting) instead of freeing the config information directly.

	usb_authorize_device() shouldn't change the device strings
	until it knows that the authorization will succeed, and it should
	autosuspend the device at the end (having autoresumed the
	device at the start).

	Because the device strings can be changed, the sysfs routines
	to display the strings must protect the string pointers by
	locking the device.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Acked-by: David Vrabel <david.vrabel@csr.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 25 insertions, 13 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 28738fa17af..0cec6caf6e9 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1849,21 +1849,23 @@ fail:
  */
 int usb_deauthorize_device(struct usb_device *usb_dev)
 {
-	unsigned cnt;
 	usb_lock_device(usb_dev);
 	if (usb_dev->authorized == 0)
 		goto out_unauthorized;
+
 	usb_dev->authorized = 0;
 	usb_set_configuration(usb_dev, -1);
+
+	kfree(usb_dev->product);
 	usb_dev->product = kstrdup("n/a (unauthorized)", GFP_KERNEL);
+	kfree(usb_dev->manufacturer);
 	usb_dev->manufacturer = kstrdup("n/a (unauthorized)", GFP_KERNEL);
+	kfree(usb_dev->serial);
 	usb_dev->serial = kstrdup("n/a (unauthorized)", GFP_KERNEL);
-	kfree(usb_dev->config);
-	usb_dev->config = NULL;
-	for (cnt = 0; cnt < usb_dev->descriptor.bNumConfigurations; cnt++)
-		kfree(usb_dev->rawdescriptors[cnt]);
+
+	usb_destroy_configuration(usb_dev);
 	usb_dev->descriptor.bNumConfigurations = 0;
-	kfree(usb_dev->rawdescriptors);
+
 out_unauthorized:
 	usb_unlock_device(usb_dev);
 	return 0;
@@ -1873,15 +1875,11 @@ out_unauthorized:
 int usb_authorize_device(struct usb_device *usb_dev)
 {
 	int result = 0, c;
+
 	usb_lock_device(usb_dev);
 	if (usb_dev->authorized == 1)
 		goto out_authorized;
-	kfree(usb_dev->product);
-	usb_dev->product = NULL;
-	kfree(usb_dev->manufacturer);
-	usb_dev->manufacturer = NULL;
-	kfree(usb_dev->serial);
-	usb_dev->serial = NULL;
+
 	result = usb_autoresume_device(usb_dev);
 	if (result < 0) {
 		dev_err(&usb_dev->dev,
@@ -1894,6 +1892,14 @@ int usb_authorize_device(struct usb_device *usb_dev)
 			"authorization: %d\n", result);
 		goto error_device_descriptor;
 	}
+
+	kfree(usb_dev->product);
+	usb_dev->product = NULL;
+	kfree(usb_dev->manufacturer);
+	usb_dev->manufacturer = NULL;
+	kfree(usb_dev->serial);
+	usb_dev->serial = NULL;
+
 	usb_dev->authorized = 1;
 	result = usb_enumerate_device(usb_dev);
 	if (result < 0)
@@ -1912,8 +1918,10 @@ int usb_authorize_device(struct usb_device *usb_dev)
 		}
 	}
 	dev_info(&usb_dev->dev, "authorized to connect\n");
+
 error_enumerate:
 error_device_descriptor:
+	usb_autosuspend_device(usb_dev);
 error_autoresume:
 out_authorized:
 	usb_unlock_device(usb_dev);	// complements locktree
diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index 15477008b63..485edf937f2 100644
--- a/drivers/usb/core/sysfs.c
+++ b/drivers/usb/core/sysfs.c
@@ -82,9 +82,13 @@ static ssize_t  show_##name(struct device *dev,				\
 		struct device_attribute *attr, char *buf)		\
 {									\
 	struct usb_device *udev;					\
+	int retval;							\
 									\
 	udev = to_usb_device(dev);					\
-	return sprintf(buf, "%s\n", udev->name);			\
+	usb_lock_device(udev);						\
+	retval = sprintf(buf, "%s\n", udev->name);			\
+	usb_unlock_device(udev);					\
+	return retval;							\
 }									\
 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL);