USB: cdc-acm: fix sysfs attribute registration bug

This patch (as950) fixes a bug in the cdc-acm driver.  It doesn't keep
track of which interface (control or data) the sysfs attributes get
registered for, and as a result, during disconnect it will sometimes
attempt to remove the attributes from the wrong interface.  The
left-over attributes can cause a crash later on, particularly if the driver
module has been unloaded.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Oliver Neukum <oneukum@suse.de>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index fe940e0536e03488016d1171da3866ce8bb6dd00..f51e22490edfaccae55b641723c939ce0019087b 100644 (file)
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -921,6 +921,10 @@ skip_normal_probe:
                        return -EINVAL;
                }
        }
+
+       /* Accept probe requests only for the control interface */
+       if (intf != control_interface)
+               return -ENODEV;
        
        if (usb_interface_claimed(data_interface)) { /* valid in this context */
                dev_dbg(&intf->dev,"The data interface isn't available");
@@ -1109,10 +1113,12 @@ static void acm_disconnect(struct usb_interface *intf)
                return;
        }
        if (acm->country_codes){
-               device_remove_file(&intf->dev, &dev_attr_wCountryCodes);
-               device_remove_file(&intf->dev, &dev_attr_iCountryCodeRelDate);
+               device_remove_file(&acm->control->dev,
+                               &dev_attr_wCountryCodes);
+               device_remove_file(&acm->control->dev,
+                               &dev_attr_iCountryCodeRelDate);
        }
-       device_remove_file(&intf->dev, &dev_attr_bmCapabilities);
+       device_remove_file(&acm->control->dev, &dev_attr_bmCapabilities);
        acm->dev = NULL;
        usb_set_intfdata(acm->control, NULL);
        usb_set_intfdata(acm->data, NULL);