linux-kernel - [PATCH 26/97] USB: fix bugs in usb_(de)authorize

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Message-Id: <1262651630-7354-26-git-send-email-gregkh@suse.de>
Date:	Mon,  4 Jan 2010 16:32:39 -0800
From:	Greg Kroah-Hartman <gregkh@...e.de>
To:	linux-kernel@...r.kernel.org, stable@...nel.org,
	stable-review@...nel.org
Cc:	torvalds@...ux-foundation.org, akpm@...ux-foundation.org,
	alan@...rguk.ukuu.org.uk, Alan Stern <stern@...land.harvard.edu>,
	Inaky Perez-Gonzalez <inaky@...ux.intel.com>,
	Greg Kroah-Hartman <gregkh@...e.de>
Subject: [PATCH 26/97] USB: fix bugs in usb_(de)authorize_device

From: Alan Stern <stern@...land.harvard.edu>

commit da307123c621b01cce147a4be313d8a754674f63 upstream.

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@...land.harvard.edu>
CC: Inaky Perez-Gonzalez <inaky@...ux.intel.com>
Acked-by: David Vrabel <david.vrabel@....com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...e.de>
---
 drivers/usb/core/hub.c   |   32 ++++++++++++++++++++------------
 drivers/usb/core/sysfs.c |    6 +++++-
 2 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 276fc68..8b0c235 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1803,21 +1803,23 @@ 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;
@@ -1827,15 +1829,11 @@ 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,
@@ -1848,6 +1846,14 @@ 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)
@@ -1866,8 +1872,10 @@ 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 7ec3041..8752e55 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);
 
-- 
1.6.6

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