commit fa16ebed31f336e41970f3f0ea9e8279f6be2d27 Author: Shlomo Pongratz Date: Mon Aug 13 14:39:49 2012 +0000 IB/ipoib: Add missing locking when CM object is deleted Commit b63b70d87741 ("IPoIB: Use a private hash table for path lookup in xmit path") introduced a bug where in ipoib_cm_destroy_tx() a CM object is moved between lists without any supported locking. Under a stress test, this eventually leads to list corruption and a crash. Previously when this routine was called, callers were taking the device priv lock. Currently this function is called from the RCU callback associated with neighbour deletion. Fix the race by taking the same lock we used to before. Signed-off-by: Shlomo Pongratz Signed-off-by: Or Gerlitz Signed-off-by: Roland Dreier diff --git a/drivers/infiniband/ulp/ipoib/ipoib_cm.c b/drivers/infiniband/ulp/ipoib/ipoib_cm.c index 95ecf4e..24683fd 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_cm.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_cm.c @@ -1271,12 +1271,15 @@ struct ipoib_cm_tx *ipoib_cm_create_tx(struct net_device *dev, struct ipoib_path void ipoib_cm_destroy_tx(struct ipoib_cm_tx *tx) { struct ipoib_dev_priv *priv = netdev_priv(tx->dev); + unsigned long flags; if (test_and_clear_bit(IPOIB_FLAG_INITIALIZED, &tx->flags)) { + spin_lock_irqsave(&priv->lock, flags); list_move(&tx->list, &priv->cm.reap_list); queue_work(ipoib_workqueue, &priv->cm.reap_task); ipoib_dbg(priv, "Reap connection for gid %pI6\n", tx->neigh->daddr + 4); tx->neigh = NULL; + spin_unlock_irqrestore(&priv->lock, flags); } }