Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759223AbcCVKxL (ORCPT ); Tue, 22 Mar 2016 06:53:11 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:56937 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758534AbcCVKnD (ORCPT ); Tue, 22 Mar 2016 06:43:03 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Maximilian Schneider , Marc Kleine-Budde , Luis Henriques Subject: [PATCH 3.16.y-ckt 115/142] can: gs_usb: fixed disconnect bug by removing erroneous use of kfree() Date: Tue, 22 Mar 2016 10:40:44 +0000 Message-Id: <1458643271-4227-116-git-send-email-luis.henriques@canonical.com> In-Reply-To: <1458643271-4227-1-git-send-email-luis.henriques@canonical.com> References: <1458643271-4227-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2569 Lines: 80 3.16.7-ckt26 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Maximilain Schneider commit e9a2d81b1761093386a0bb8a4f51642ac785ef63 upstream. gs_destroy_candev() erroneously calls kfree() on a struct gs_can *, which is allocated through alloc_candev() and should instead be freed using free_candev() alone. The inappropriate use of kfree() causes the kernel to hang when gs_destroy_candev() is called. Only the struct gs_usb * which is allocated through kzalloc() should be freed using kfree() when the device is disconnected. Signed-off-by: Maximilian Schneider Signed-off-by: Marc Kleine-Budde Signed-off-by: Luis Henriques --- drivers/net/can/usb/gs_usb.c | 24 +++++++++++------------- 1 file changed, 11 insertions(+), 13 deletions(-) diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c index 04b0f84612f0..047b63caa3b7 100644 --- a/drivers/net/can/usb/gs_usb.c +++ b/drivers/net/can/usb/gs_usb.c @@ -825,9 +825,8 @@ static struct gs_can *gs_make_candev(unsigned int channel, struct usb_interface static void gs_destroy_candev(struct gs_can *dev) { unregister_candev(dev->netdev); - free_candev(dev->netdev); usb_kill_anchored_urbs(&dev->tx_submitted); - kfree(dev); + free_candev(dev->netdev); } static int gs_usb_probe(struct usb_interface *intf, const struct usb_device_id *id) @@ -910,12 +909,15 @@ static int gs_usb_probe(struct usb_interface *intf, const struct usb_device_id * for (i = 0; i < icount; i++) { dev->canch[i] = gs_make_candev(i, intf); if (IS_ERR_OR_NULL(dev->canch[i])) { + /* save error code to return later */ + rc = PTR_ERR(dev->canch[i]); + /* on failure destroy previously created candevs */ icount = i; - for (i = 0; i < icount; i++) { + for (i = 0; i < icount; i++) gs_destroy_candev(dev->canch[i]); - dev->canch[i] = NULL; - } + + usb_kill_anchored_urbs(&dev->rx_submitted); kfree(dev); return rc; } @@ -936,16 +938,12 @@ static void gs_usb_disconnect(struct usb_interface *intf) return; } - for (i = 0; i < GS_MAX_INTF; i++) { - struct gs_can *can = dev->canch[i]; - - if (!can) - continue; - - gs_destroy_candev(can); - } + for (i = 0; i < GS_MAX_INTF; i++) + if (dev->canch[i]) + gs_destroy_candev(dev->canch[i]); usb_kill_anchored_urbs(&dev->rx_submitted); + kfree(dev); } static const struct usb_device_id gs_usb_table[] = {