From 580da35a31f91a594f3090b7a2c39b85cb051a12 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 29 Nov 2011 22:31:23 +0100 Subject: IB: Fix RCU lockdep splats Commit f2c31e32b37 ("net: fix NULL dereferences in check_peer_redir()") forgot to take care of infiniband uses of dst neighbours. Many thanks to Marc Aurele who provided a nice bug report and feedback. Reported-by: Marc Aurele La France Signed-off-by: Eric Dumazet Cc: David Miller Cc: Signed-off-by: Roland Dreier --- drivers/infiniband/ulp/ipoib/ipoib_main.c | 18 +++++++++++------- drivers/infiniband/ulp/ipoib/ipoib_multicast.c | 6 ++++-- 2 files changed, 15 insertions(+), 9 deletions(-) (limited to 'drivers/infiniband/ulp/ipoib') diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c index 7567b600023..ef38848d1b0 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_main.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c @@ -555,6 +555,7 @@ static int path_rec_start(struct net_device *dev, return 0; } +/* called with rcu_read_lock */ static void neigh_add_path(struct sk_buff *skb, struct net_device *dev) { struct ipoib_dev_priv *priv = netdev_priv(dev); @@ -636,6 +637,7 @@ err_drop: spin_unlock_irqrestore(&priv->lock, flags); } +/* called with rcu_read_lock */ static void ipoib_path_lookup(struct sk_buff *skb, struct net_device *dev) { struct ipoib_dev_priv *priv = netdev_priv(skb->dev); @@ -720,13 +722,14 @@ static int ipoib_start_xmit(struct sk_buff *skb, struct net_device *dev) struct neighbour *n = NULL; unsigned long flags; + rcu_read_lock(); if (likely(skb_dst(skb))) n = dst_get_neighbour(skb_dst(skb)); if (likely(n)) { if (unlikely(!*to_ipoib_neigh(n))) { ipoib_path_lookup(skb, dev); - return NETDEV_TX_OK; + goto unlock; } neigh = *to_ipoib_neigh(n); @@ -749,17 +752,17 @@ static int ipoib_start_xmit(struct sk_buff *skb, struct net_device *dev) ipoib_neigh_free(dev, neigh); spin_unlock_irqrestore(&priv->lock, flags); ipoib_path_lookup(skb, dev); - return NETDEV_TX_OK; + goto unlock; } if (ipoib_cm_get(neigh)) { if (ipoib_cm_up(neigh)) { ipoib_cm_send(dev, skb, ipoib_cm_get(neigh)); - return NETDEV_TX_OK; + goto unlock; } } else if (neigh->ah) { ipoib_send(dev, skb, neigh->ah, IPOIB_QPN(n->ha)); - return NETDEV_TX_OK; + goto unlock; } if (skb_queue_len(&neigh->queue) < IPOIB_MAX_PATH_REC_QUEUE) { @@ -793,13 +796,14 @@ static int ipoib_start_xmit(struct sk_buff *skb, struct net_device *dev) phdr->hwaddr + 4); dev_kfree_skb_any(skb); ++dev->stats.tx_dropped; - return NETDEV_TX_OK; + goto unlock; } unicast_arp_send(skb, dev, phdr); } } - +unlock: + rcu_read_unlock(); return NETDEV_TX_OK; } @@ -837,7 +841,7 @@ static int ipoib_hard_header(struct sk_buff *skb, dst = skb_dst(skb); n = NULL; if (dst) - n = dst_get_neighbour(dst); + n = dst_get_neighbour_raw(dst); if ((!dst || !n) && daddr) { struct ipoib_pseudoheader *phdr = (struct ipoib_pseudoheader *) skb_push(skb, sizeof *phdr); diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c index 1b7a9768635..cad1894594a 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c @@ -266,7 +266,7 @@ static int ipoib_mcast_join_finish(struct ipoib_mcast *mcast, skb->dev = dev; if (dst) - n = dst_get_neighbour(dst); + n = dst_get_neighbour_raw(dst); if (!dst || !n) { /* put pseudoheader back on for next time */ skb_push(skb, sizeof (struct ipoib_pseudoheader)); @@ -722,6 +722,8 @@ out: if (mcast && mcast->ah) { struct dst_entry *dst = skb_dst(skb); struct neighbour *n = NULL; + + rcu_read_lock(); if (dst) n = dst_get_neighbour(dst); if (n && !*to_ipoib_neigh(n)) { @@ -734,7 +736,7 @@ out: list_add_tail(&neigh->list, &mcast->neigh_list); } } - + rcu_read_unlock(); spin_unlock_irqrestore(&priv->lock, flags); ipoib_send(dev, skb, mcast->ah, IB_MULTICAST_QPN); return; -- cgit v1.2.3