From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5DE67C433E0 for ; Wed, 29 Jul 2020 20:23:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3ED122067D for ; Wed, 29 Jul 2020 20:23:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726606AbgG2UX3 (ORCPT ); Wed, 29 Jul 2020 16:23:29 -0400 Received: from netrider.rowland.org ([192.131.102.5]:47653 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1726365AbgG2UX3 (ORCPT ); Wed, 29 Jul 2020 16:23:29 -0400 Received: (qmail 1585094 invoked by uid 1000); 29 Jul 2020 16:23:28 -0400 Date: Wed, 29 Jul 2020 16:23:28 -0400 From: Alan Stern To: Felipe Balbi Cc: Anton Vasilyev , Evgeny Novikov , Benjamin Herrenschmidt , USB mailing list Subject: [PATCH RFC 3/4] USB: UDC: net2280: Fix memory leaks Message-ID: <20200729202328.GD1584059@rowland.harvard.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org As Anton and Evgeny have noted, the net2280 UDC driver has a problem with leaking memory along some of its failure pathways. It also has another problem, not previously noted, in that some of the failure pathways will call usb_del_gadget_udc() without first calling usb_add_gadget_udc_release(). And it leaks memory by calling kfree() when it should call put_device(). Previous attempts to fix the problems have failed because of lack of support in the UDC core for separately initializing and adding gadgets, or for separately deleting and freeing gadgets. The previous patch in this series adds the necessary support, making it possible to fix the outstanding problems properly. This patch adds an "added" flag to the net2280 structure to indicate whether or not the gadget has been registered (and thus whether or not to call usb_del_gadget()), and it fixes the deallocation issues by calling usb_put_gadget() at the appropriate point. A similar memory leak issue, apparently never before recognized, stems from the fact that the driver never initializes the drvdata field in the gadget's embedded struct device! Evidently this wasn't noticed because the pointer is only ever used as an argument to kfree(), which doesn't mind getting called with a NULL pointer. Signed-off-by: Alan Stern Reported-By: Anton Vasilyev Reported-By: Evgeny Novikov CC: Benjamin Herrenschmidt --- drivers/usb/gadget/udc/net2280.c | 10 +++++++--- drivers/usb/gadget/udc/net2280.h | 1 + 2 files changed, 8 insertions(+), 3 deletions(-) Index: usb-devel/drivers/usb/gadget/udc/net2280.c =================================================================== --- usb-devel.orig/drivers/usb/gadget/udc/net2280.c +++ usb-devel/drivers/usb/gadget/udc/net2280.c @@ -3572,7 +3572,8 @@ static void net2280_remove(struct pci_de { struct net2280 *dev = pci_get_drvdata(pdev); - usb_del_gadget_udc(&dev->gadget); + if (dev->added) + usb_del_gadget(&dev->gadget); BUG_ON(dev->driver); @@ -3603,6 +3604,7 @@ static void net2280_remove(struct pci_de device_remove_file(&pdev->dev, &dev_attr_registers); ep_info(dev, "unbind\n"); + usb_put_gadget(&dev->gadget); } /* wrap this driver around the specified device, but @@ -3624,6 +3626,8 @@ static int net2280_probe(struct pci_dev } pci_set_drvdata(pdev, dev); + dev_set_drvdata(&dev->gadget.dev, dev); + usb_initialize_gadget(&pdev->dev, &dev->gadget, gadget_release); spin_lock_init(&dev->lock); dev->quirks = id->driver_data; dev->pdev = pdev; @@ -3774,10 +3778,10 @@ static int net2280_probe(struct pci_dev if (retval) goto done; - retval = usb_add_gadget_udc_release(&pdev->dev, &dev->gadget, - gadget_release); + retval = usb_add_gadget(&dev->gadget); if (retval) goto done; + dev->added = 1; return 0; done: Index: usb-devel/drivers/usb/gadget/udc/net2280.h =================================================================== --- usb-devel.orig/drivers/usb/gadget/udc/net2280.h +++ usb-devel/drivers/usb/gadget/udc/net2280.h @@ -156,6 +156,7 @@ struct net2280 { softconnect : 1, got_irq : 1, region:1, + added:1, u1_enable:1, u2_enable:1, ltm_enable:1,