IPoIB: Close race in setting mcast->ah
ipoib_mcast_send() tests mcast->ah twice. If this value is changed
between these two points, we leak an skb. However,
ipoib_mcast_join_finish() sets mcast->ah with no locking, so it could
race against ipoib_mcast_send().
As a solution, take priv->lock around assignment to mcast->ah thus
making sure ipoib_mcast_send() (which also takes priv->lock) is not in
flight.
Signed-off-by: Eli Cohen <eli@mellanox.co.il>
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
index a2408d7..e5dc2a0 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
@@ -213,6 +213,7 @@
{
struct net_device *dev = mcast->dev;
struct ipoib_dev_priv *priv = netdev_priv(dev);
+ struct ipoib_ah *ah;
int ret;
mcast->mcmember = *mcmember;
@@ -269,8 +270,8 @@
av.static_rate, priv->local_rate,
ib_sa_rate_enum_to_int(mcast->mcmember.rate));
- mcast->ah = ipoib_create_ah(dev, priv->pd, &av);
- if (!mcast->ah) {
+ ah = ipoib_create_ah(dev, priv->pd, &av);
+ if (!ah) {
ipoib_warn(priv, "ib_address_create failed\n");
} else {
ipoib_dbg_mcast(priv, "MGID " IPOIB_GID_FMT
@@ -280,6 +281,10 @@
be16_to_cpu(mcast->mcmember.mlid),
mcast->mcmember.sl);
}
+
+ spin_lock_irq(&priv->lock);
+ mcast->ah = ah;
+ spin_unlock_irq(&priv->lock);
}
/* actually send any queued packets */