From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alan Stern , Felipe Balbi Subject: [ 21/71] usb: gadget: fix a bug and a WARN_ON in dummy-hcd Date: Sun, 29 Sep 2013 12:27:33 -0700 Message-Id: <20130929192644.973119105@linuxfoundation.org> In-Reply-To: <20130929192643.539596256@linuxfoundation.org> References: <20130929192643.539596256@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alan Stern commit 5f5610f69be3a925b1f79af27150bb7377bc9ad6 upstream. This patch fixes a NULL pointer dereference and a WARN_ON in dummy-hcd. These things were the result of moving to the UDC core framework, and possibly of changes to that framework. Now unloading a gadget driver causes the UDC to be stopped after the gadget driver is unbound, not before. Therefore the "driver" argument to dummy_udc_stop() can be NULL, so we must not try to print the driver's name without checking first. Also, the UDC framework automatically unregisters the gadget when the UDC is deleted. Therefore a sysfs attribute file attached to the gadget must be removed before the UDC is deleted, not after. Signed-off-by: Alan Stern Signed-off-by: Felipe Balbi Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/dummy_hcd.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/drivers/usb/gadget/dummy_hcd.c +++ b/drivers/usb/gadget/dummy_hcd.c @@ -923,8 +923,9 @@ static int dummy_udc_stop(struct usb_gad struct dummy_hcd *dum_hcd = gadget_to_dummy_hcd(g); struct dummy *dum = dum_hcd->dum; - dev_dbg(udc_dev(dum), "unregister gadget driver '%s'\n", - driver->driver.name); + if (driver) + dev_dbg(udc_dev(dum), "unregister gadget driver '%s'\n", + driver->driver.name); dum->driver = NULL; @@ -1000,8 +1001,8 @@ static int dummy_udc_remove(struct platf { struct dummy *dum = platform_get_drvdata(pdev); - usb_del_gadget_udc(&dum->gadget); device_remove_file(&dum->gadget.dev, &dev_attr_function); + usb_del_gadget_udc(&dum->gadget); return 0; }