[ 80/80] can: Do not call dev_put if restart timer is running upon close

From: Greg Kroah-Hartman
Date: Wed Jan 09 2013 - 15:56:54 EST


3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxxxxxxxx>

commit ab48b03ec9ae1840a1e427e2375bd0d9d554b4ed upstream.

If the restart timer is running due to BUS-OFF and the device is
disconnected an dev_put will decrease the usage counter to -1 thus
blocking the interface removal, resulting in the following dmesg
lines repeating every 10s:
can: notifier: receive list not found for dev can0
can: notifier: receive list not found for dev can0
can: notifier: receive list not found for dev can0
unregister_netdevice: waiting for can0 to become free. Usage count = -1

Signed-off-by: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/net/can/dev.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/net/can/dev.c
+++ b/drivers/net/can/dev.c
@@ -576,8 +576,7 @@ void close_candev(struct net_device *dev
{
struct can_priv *priv = netdev_priv(dev);

- if (del_timer_sync(&priv->restart_timer))
- dev_put(dev);
+ del_timer_sync(&priv->restart_timer);
can_flush_echo_skb(dev);
}
EXPORT_SYMBOL_GPL(close_candev);


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