From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760902AbbA1EQd (ORCPT ); Tue, 27 Jan 2015 23:16:33 -0500 Received: from mail.kernel.org ([198.145.29.136]:37727 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755008AbbA1EQ0 (ORCPT ); Tue, 27 Jan 2015 23:16:26 -0500 From: lizf@kernel.org To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Joe Lawrence , Greg Kroah-Hartman , Zefan Li Subject: [PATCH 3.4 33/91] usb: hub: take hub->hdev reference when processing from eventlist Date: Wed, 28 Jan 2015 12:07:13 +0800 Message-Id: <1422418236-12852-66-git-send-email-lizf@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1422418050-12581-1-git-send-email-lizf@kernel.org> References: <1422418050-12581-1-git-send-email-lizf@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joe Lawrence 3.4.105-rc1 review patch. If anyone has any objections, please let me know. ------------------ 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: Zefan Li --- 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 e0d4d90..62a9e44 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -3729,9 +3729,10 @@ 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", @@ -3946,6 +3947,7 @@ 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