HID: hiddev: fix memory corruption due to invalid intfdata

Commit bd25f4dd69 ("HID: hiddev: use usb_find_interface,
get rid of BKL") introduced using of private intfdata in hiddev for
purpose of storing hiddev pointer.

This is a problem, because intf pointer is already being set to struct
hid_device pointer by HID core. This obviously lead to memory corruptions
at device disconnect time, such as

WARNING: at lib/kobject.c:595 kobject_put+0x37/0x4b()
kobject: '(null)' (ffff88011e9cd898): is not initialized, yet kobject_put() is being called.

Convert hiddev into accessing hiddev through struct hid_device which is
in intfdata already.

Reported-and-tested-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Reported-and-tested-by: Heinz Diehl <htd@fritha.org>
Reported-and-tested-by: Alan Ott <alan@signal11.us>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
Jiri Kosina 2010-08-13 12:19:45 +02:00
parent 7032269e87
commit 9c9e54a8df

View File

@ -266,13 +266,15 @@ static int hiddev_open(struct inode *inode, struct file *file)
{
struct hiddev_list *list;
struct usb_interface *intf;
struct hid_device *hid;
struct hiddev *hiddev;
int res;
intf = usb_find_interface(&hiddev_driver, iminor(inode));
if (!intf)
return -ENODEV;
hiddev = usb_get_intfdata(intf);
hid = usb_get_intfdata(intf);
hiddev = hid->hiddev;
if (!(list = kzalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
return -ENOMEM;
@ -890,7 +892,6 @@ int hiddev_connect(struct hid_device *hid, unsigned int force)
hid->hiddev = hiddev;
hiddev->hid = hid;
hiddev->exist = 1;
usb_set_intfdata(usbhid->intf, usbhid);
retval = usb_register_dev(usbhid->intf, &hiddev_class);
if (retval) {
err_hid("Not able to get a minor for this device.");