From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755973Ab3KMB36 (ORCPT ); Tue, 12 Nov 2013 20:29:58 -0500 Received: from mga14.intel.com ([143.182.124.37]:15513 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755359Ab3KMB3r (ORCPT ); Tue, 12 Nov 2013 20:29:47 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.93,689,1378882800"; d="scan'208";a="426554509" Subject: [PATCH V2] usbnet: fix race condition caused spinlock bad magic issue From: wangbiao To: oneukum@suse.de, netdev@vger.kernel.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Ingo Molnar Cc: akpm@linux-foundation.org, mingo@elte.hu, a.p.zijlstra@chello.nl, rusty@rustcorp.com.au, william.douglas@intel.com, di.zhang@intel.com, biao.wang@intel.com Content-Type: text/plain; charset="us-ascii" Date: Wed, 13 Nov 2013 09:11:25 +0800 Message-ID: <1384305085.19509.5.camel@wangbiao> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: wang, biao Date: Mon, 11 Nov 2013 10:23:40 +0800 Subject: [PATCH] usbnet: fix race condition caused spinlock bad magic issue 1, there is race between usbnet_terminate_urbs and usbnet_bh, when unlink_wakeup used in usbnet_bh, it may be already freed and used by other function as unlink_wakeup was a local var on stack. for example: cpu 0: cpu 1: usb_suspend_both ->usbnet_suspend usbnet_bh ->usbnet_terminate_urbs ->__wake_up ->_raw_spin_unlock_irqrestore ->do_raw_spin_unlock ->spin_bug when usbnet_terminate_urbs complete execution and memory of unlink_wakeup was used by other function, then usbnet_bh may still use it. 2, for the same reason,dev->wait should be judged again before use it, as between the judge point(if(dev->wait)) and use point(wakeup(dev->wait)), the dev->wait may be set NULL by another cpu. for issue 1, declare unlink_wakeup in global section instead of on stack. for issue 2, use a temporary local var to keep the value of dev->wait in stack and judge it before using. Signed-off-by: wang, biao Acked-by: Ingo Molnar Acked-by: Oliver Neukum Acked-by: Zhang, Di --- drivers/net/usb/usbnet.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index 90a429b..0603ef6 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -86,6 +86,7 @@ static const char driver_name [] = "usbnet"; /* use ethtool to change the level for any given device */ static int msg_level = -1; +static DECLARE_WAIT_QUEUE_HEAD(unlink_wakeup); module_param (msg_level, int, 0); MODULE_PARM_DESC (msg_level, "Override default message level"); @@ -761,7 +762,6 @@ EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs); // precondition: never called in_interrupt static void usbnet_terminate_urbs(struct usbnet *dev) { - DECLARE_WAIT_QUEUE_HEAD_ONSTACK(unlink_wakeup); DECLARE_WAITQUEUE(wait, current); int temp; @@ -1449,7 +1449,9 @@ static void usbnet_bh (unsigned long param) // waiting for all pending urbs to complete? if (dev->wait) { if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) { - wake_up (dev->wait); + wait_queue_head_t *wait_d = dev->wait; + if (wait_d) + wake_up(wait_d); } // or are we maybe short a few urbs? -- 1.7.0.4