Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758466AbaJIVW2 (ORCPT ); Thu, 9 Oct 2014 17:22:28 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:59533 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757742AbaJIVKs (ORCPT ); Thu, 9 Oct 2014 17:10:48 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Joe Lawrence , Greg Kroah-Hartman , Kamal Mostafa Subject: [PATCH 3.13 049/163] usb: hub: take hub->hdev reference when processing from eventlist Date: Thu, 9 Oct 2014 14:01:14 -0700 Message-Id: <1412888588-26755-50-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1412888588-26755-1-git-send-email-kamal@canonical.com> References: <1412888588-26755-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.13.11.9 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Joe Lawrence commit c605f3cdff53a743f6d875b76956b239deca1272 upstream. During surprise device hotplug removal tests, it was observed that hub_events may try to call usb_lock_device on a device that has already been freed. Protect the usb_device by taking out a reference (under the hub_event_lock) when hub_events pulls it off the list, returning the reference after hub_events is finished using it. Signed-off-by: Joe Lawrence Suggested-by: David Bulkow for using kref Suggested-by: Alan Stern for placement Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman Signed-off-by: Kamal Mostafa --- drivers/usb/core/hub.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index a80e195..9f179ea 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -4729,9 +4729,10 @@ static void hub_events(void) hub = list_entry(tmp, struct usb_hub, event_list); kref_get(&hub->kref); + hdev = hub->hdev; + usb_get_dev(hdev); spin_unlock_irq(&hub_event_lock); - hdev = hub->hdev; hub_dev = hub->intfdev; intf = to_usb_interface(hub_dev); dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n", @@ -4944,6 +4945,7 @@ static void hub_events(void) usb_autopm_put_interface(intf); loop_disconnected: usb_unlock_device(hdev); + usb_put_dev(hdev); kref_put(&hub->kref, hub_release); } /* end while (1) */ -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/