From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754255AbdBPATJ (ORCPT ); Wed, 15 Feb 2017 19:19:09 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:53697 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753110AbdBOXNZ (ORCPT ); Wed, 15 Feb 2017 18:13:25 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "=?UTF-8?q?=EC=B6=94=EC=A7=80=ED=98=B8?=" , "Marc Kleine-Budde" Date: Wed, 15 Feb 2017 22:41:41 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 284/306] can: peak: fix bad memory access and free sequence In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.40-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: 추지호 commit b67d0dd7d0dc9e456825447bbeb935d8ef43ea7c upstream. Fix for bad memory access while disconnecting. netdev is freed before private data free, and dev is accessed after freeing netdev. This makes a slub problem, and it raise kernel oops with slub debugger config. Signed-off-by: Jiho Chu Signed-off-by: Marc Kleine-Budde Signed-off-by: Ben Hutchings --- drivers/net/can/usb/peak_usb/pcan_usb_core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/net/can/usb/peak_usb/pcan_usb_core.c +++ b/drivers/net/can/usb/peak_usb/pcan_usb_core.c @@ -826,23 +826,25 @@ lbl_free_candev: static void peak_usb_disconnect(struct usb_interface *intf) { struct peak_usb_device *dev; + struct peak_usb_device *dev_prev_siblings; /* unregister as many netdev devices as siblings */ - for (dev = usb_get_intfdata(intf); dev; dev = dev->prev_siblings) { + for (dev = usb_get_intfdata(intf); dev; dev = dev_prev_siblings) { struct net_device *netdev = dev->netdev; char name[IFNAMSIZ]; + dev_prev_siblings = dev->prev_siblings; dev->state &= ~PCAN_USB_STATE_CONNECTED; strncpy(name, netdev->name, IFNAMSIZ); unregister_netdev(netdev); - free_candev(netdev); kfree(dev->cmd_buf); dev->next_siblings = NULL; if (dev->adapter->dev_free) dev->adapter->dev_free(dev); + free_candev(netdev); dev_info(&intf->dev, "%s removed\n", name); }