Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763558AbYCUXsF (ORCPT ); Fri, 21 Mar 2008 19:48:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754975AbYCUXpl (ORCPT ); Fri, 21 Mar 2008 19:45:41 -0400 Received: from 216-99-217-87.dsl.aracnet.com ([216.99.217.87]:60189 "EHLO sous-sol.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752651AbYCUXp2 (ORCPT ); Fri, 21 Mar 2008 19:45:28 -0400 Message-Id: <20080321224335.920240276@sous-sol.org> References: <20080321224250.144333319@sous-sol.org> User-Agent: quilt/0.46-1 Date: Fri, 21 Mar 2008 15:42:59 -0700 From: Chris Wright To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Matti Linnanvuori , David S Miller , Greg Kroah-Hartman Subject: [patch 09/76] NET: Fix race in dev_close(). (Bug 9750) Content-Disposition: inline; filename=net-fix-race-in-dev_close.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1904 Lines: 53 -stable review patch. If anyone has any objections, please let us know. --------------------- From: Matti Linnanvuori Upstream commit: d8b2a4d21e0b37b9669b202867bfef19f68f786a There is a race in Linux kernel file net/core/dev.c, function dev_close. The function calls function dev_deactivate, which calls function dev_watchdog_down that deletes the watchdog timer. However, after that, a driver can call netif_carrier_ok, which calls function __netdev_watchdog_up that can add the watchdog timer again. Function unregister_netdevice calls function dev_shutdown that traps the bug !timer_pending(&dev->watchdog_timer). Moving dev_deactivate after netif_running() has been cleared prevents function netif_carrier_on from calling __netdev_watchdog_up and adding the watchdog timer again. Signed-off-by: Matti Linnanvuori Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman Signed-off-by: Chris Wright --- net/core/dev.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1068,8 +1068,6 @@ int dev_close(struct net_device *dev) */ call_netdevice_notifiers(NETDEV_GOING_DOWN, dev); - dev_deactivate(dev); - clear_bit(__LINK_STATE_START, &dev->state); /* Synchronize to scheduled poll. We cannot touch poll list, @@ -1080,6 +1078,8 @@ int dev_close(struct net_device *dev) */ smp_mb__after_clear_bit(); /* Commit netif_running(). */ + dev_deactivate(dev); + /* * Call the device specific close. This cannot fail. * Only if device is UP -- -- 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/