Commit 5830725f authored May 10, 2007 by Thomas Graf Committed by David S. Miller May 10, 2007

[NET]: Fix dev->qdisc race for NETDEV_TX_LOCKED case



When transmit fails with NETDEV_TX_LOCKED the skb is requeued
to dev->qdisc again. The dev->qdisc pointer is protected by
the queue lock which needs to be dropped when attempting to
transmit and acquired again before requeing. The problem is
that qdisc_restart() fetches the dev->qdisc pointer once and
stores it in the `q' variable which is invalidated when
dropping the queue_lock, therefore the variable needs to be
refreshed before requeueing.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent fc038410

net/sched/sch_generic.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -139,6 +139,7 @@ static inline int qdisc_restart(struct net_device *dev)
		}
		if (ret == NETDEV_TX_LOCKED && nolock) {
		spin_lock(&dev->queue_lock);
		q = dev->qdisc;
		goto collision;
		}
		}