Messages in this thread Patch in this message | | | Date | Fri, 21 Mar 2008 15:42:59 -0700 | From | Chris Wright <> | Subject | [patch 09/76] NET: Fix race in dev_close(). (Bug 9750) |
| |
-stable review patch. If anyone has any objections, please let us know. ---------------------
From: Matti Linnanvuori <mattilinnanvuori@yahoo.com>
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 <mattilinnanvuori@yahoo.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Chris Wright <chrisw@sous-sol.org>
--- 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 --
| |