Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752661AbdHPNrk (ORCPT ); Wed, 16 Aug 2017 09:47:40 -0400 Received: from bran.ispras.ru ([83.149.199.196]:15258 "EHLO smtp.ispras.ru" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751714AbdHPNri (ORCPT ); Wed, 16 Aug 2017 09:47:38 -0400 From: Anton Vasilyev To: Felipe Balbi Cc: Anton Vasilyev , Greg Kroah-Hartman , Alan Stern , Jussi Kivilinna , Peter Senna Tschudin , Raz Manor , Romain Perier , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, ldv-project@linuxtesting.org Subject: [PATCH] udc: Memory leak on error path and use after free Date: Wed, 16 Aug 2017 16:47:28 +0300 Message-Id: <1502891248-7827-1-git-send-email-vasilyev@ispras.ru> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1846 Lines: 59 gadget_release() is responsible for cleanup dev memory. But if net2280_probe() fails after dev allocation, then gadget_release() become unregistered and dev memory leaks. Also net2280_remove() calls usb_del_gadget_udc() which perform schedule_delayed_work() with gadget_release(), so it is possible that dev will be deallocated exactly after this call and leads to use after free. The patch moves deallocation from gadget_release() to net2280_remove(). Found by Linux Driver Verififcation project (linuxtesting.org). Signed-off-by: Anton Vasilyev --- drivers/usb/gadget/udc/net2280.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-) diff --git a/drivers/usb/gadget/udc/net2280.c b/drivers/usb/gadget/udc/net2280.c index f608c1f..62ac876 100644 --- a/drivers/usb/gadget/udc/net2280.c +++ b/drivers/usb/gadget/udc/net2280.c @@ -3546,15 +3546,6 @@ static irqreturn_t net2280_irq(int irq, void *_dev) return IRQ_HANDLED; } -/*-------------------------------------------------------------------------*/ - -static void gadget_release(struct device *_dev) -{ - struct net2280 *dev = dev_get_drvdata(_dev); - - kfree(dev); -} - /* tear down the binding between this driver and the pci device */ static void net2280_remove(struct pci_dev *pdev) @@ -3592,6 +3583,8 @@ static void net2280_remove(struct pci_dev *pdev) device_remove_file(&pdev->dev, &dev_attr_registers); ep_info(dev, "unbind\n"); + + kfree(dev); } /* wrap this driver around the specified device, but @@ -3769,8 +3762,7 @@ static int net2280_probe(struct pci_dev *pdev, const struct pci_device_id *id) if (retval) goto done; - retval = usb_add_gadget_udc_release(&pdev->dev, &dev->gadget, - gadget_release); + retval = usb_add_gadget_udc(&pdev->dev, &dev->gadget); if (retval) goto done; return 0; -- 2.7.4