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| author | Matti Linnanvuori <mattilinnanvuori@yahoo.com> | 2008-02-12 23:10:11 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-02-12 23:11:16 -0800 |
| commit | d8b2a4d21e0b37b9669b202867bfef19f68f786a (patch) | |
| tree | 4e60a1971f7705ea1837a3e5c1cb9b71c0bd7fa1 /net/core/dev.c | |
| parent | b318e0e4ef4e85812c25afa19f75addccc834cd4 (diff) | |
| download | linux-d8b2a4d21e0b37b9669b202867bfef19f68f786a.tar.bz2 | |
[NET]: Fix race in dev_close(). (Bug 9750)
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>
Diffstat (limited to 'net/core/dev.c')
| -rw-r--r-- | net/core/dev.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 9549417250bb..6cfc1238c4a6 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1071,8 +1071,6 @@ 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, @@ -1083,6 +1081,8 @@ 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 |