Commit da307123 authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
Browse files

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: default avatarAlan Stern <stern@rowland.harvard.edu>
CC: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Acked-by: default avatarDavid Vrabel <david.vrabel@csr.com>
Cc: stable <stable@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 8d8558d1

drivers/usb/core/hub.c

+20 −12
Original line number Diff line number Diff line
@@ -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

drivers/usb/core/sysfs.c

+5 −1
Original line number Diff line number Diff line
@@ -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);

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