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 <tsi@ualberta.ca>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>
Cc: <stable@kernel.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

diff --git a/drivers/infiniband/core/addr.c b/drivers/infiniband/core/addr.c
index 691276b..e9cf51b 100644 (file)
--- a/drivers/infiniband/core/addr.c
+++ b/drivers/infiniband/core/addr.c
@@ -216,7 +216,9 @@ static int addr4_resolve(struct sockaddr_in *src_in,
 
        neigh = neigh_lookup(&arp_tbl, &rt->rt_gateway, rt->dst.dev);
        if (!neigh || !(neigh->nud_state & NUD_VALID)) {
+               rcu_read_lock();
                neigh_event_send(dst_get_neighbour(&rt->dst), NULL);
+               rcu_read_unlock();
                ret = -ENODATA;
                if (neigh)
                        goto release;
@@ -274,15 +276,16 @@ static int addr6_resolve(struct sockaddr_in6 *src_in,
                goto put;
        }
 
+       rcu_read_lock();
        neigh = dst_get_neighbour(dst);
        if (!neigh || !(neigh->nud_state & NUD_VALID)) {
                if (neigh)
                        neigh_event_send(neigh, NULL);
                ret = -ENODATA;
-               goto put;
+       } else {
+               ret = rdma_copy_addr(addr, dst->dev, neigh->ha);
        }
-
-       ret = rdma_copy_addr(addr, dst->dev, neigh->ha);
+       rcu_read_unlock();
 put:
        dst_release(dst);
        return ret;

diff --git a/drivers/infiniband/hw/cxgb3/iwch_cm.c b/drivers/infiniband/hw/cxgb3/iwch_cm.c
index de6d077..c88b12b 100644 (file)
--- a/drivers/infiniband/hw/cxgb3/iwch_cm.c
+++ b/drivers/infiniband/hw/cxgb3/iwch_cm.c
@@ -1375,8 +1375,10 @@ static int pass_accept_req(struct t3cdev *tdev, struct sk_buff *skb, void *ctx)
                goto reject;
        }
        dst = &rt->dst;
+       rcu_read_lock();
        neigh = dst_get_neighbour(dst);
        l2t = t3_l2t_get(tdev, neigh, neigh->dev);
+       rcu_read_unlock();
        if (!l2t) {
                printk(KERN_ERR MOD "%s - failed to allocate l2t entry!\n",
                       __func__);
@@ -1946,10 +1948,12 @@ int iwch_connect(struct iw_cm_id *cm_id, struct iw_cm_conn_param *conn_param)
        }
        ep->dst = &rt->dst;
 
+       rcu_read_lock();
        neigh = dst_get_neighbour(ep->dst);
 
        /* get a l2t entry */
        ep->l2t = t3_l2t_get(ep->com.tdev, neigh, neigh->dev);
+       rcu_read_unlock();
        if (!ep->l2t) {
                printk(KERN_ERR MOD "%s - cannot alloc l2e.\n", __func__);
                err = -ENOMEM;

diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
index b36cdac..75b57be 100644 (file)
--- a/drivers/infiniband/hw/cxgb4/cm.c
+++ b/drivers/infiniband/hw/cxgb4/cm.c
@@ -1594,6 +1594,7 @@ static int pass_accept_req(struct c4iw_dev *dev, struct sk_buff *skb)
                goto reject;
        }
        dst = &rt->dst;
+       rcu_read_lock();
        neigh = dst_get_neighbour(dst);
        if (neigh->dev->flags & IFF_LOOPBACK) {
                pdev = ip_dev_find(&init_net, peer_ip);
@@ -1620,6 +1621,7 @@ static int pass_accept_req(struct c4iw_dev *dev, struct sk_buff *skb)
                rss_qid = dev->rdev.lldi.rxq_ids[
                          cxgb4_port_idx(neigh->dev) * step];
        }
+       rcu_read_unlock();
        if (!l2t) {
                printk(KERN_ERR MOD "%s - failed to allocate l2t entry!\n",
                       __func__);
@@ -1820,6 +1822,7 @@ static int c4iw_reconnect(struct c4iw_ep *ep)
        }
        ep->dst = &rt->dst;
 
+       rcu_read_lock();
        neigh = dst_get_neighbour(ep->dst);
 
        /* get a l2t entry */
@@ -1856,6 +1859,7 @@ static int c4iw_reconnect(struct c4iw_ep *ep)
                ep->rss_qid = ep->com.dev->rdev.lldi.rxq_ids[
                        cxgb4_port_idx(neigh->dev) * step];
        }
+       rcu_read_unlock();
        if (!ep->l2t) {
                printk(KERN_ERR MOD "%s - cannot alloc l2e.\n", __func__);
                err = -ENOMEM;
@@ -2301,6 +2305,7 @@ int c4iw_connect(struct iw_cm_id *cm_id, struct iw_cm_conn_param *conn_param)
        }
        ep->dst = &rt->dst;
 
+       rcu_read_lock();
        neigh = dst_get_neighbour(ep->dst);
 
        /* get a l2t entry */
@@ -2339,6 +2344,7 @@ int c4iw_connect(struct iw_cm_id *cm_id, struct iw_cm_conn_param *conn_param)
                ep->retry_with_mpa_v1 = 0;
                ep->tried_with_mpa_v1 = 0;
        }
+       rcu_read_unlock();
        if (!ep->l2t) {
                printk(KERN_ERR MOD "%s - cannot alloc l2e.\n", __func__);
                err = -ENOMEM;

diff --git a/drivers/infiniband/hw/nes/nes_cm.c b/drivers/infiniband/hw/nes/nes_cm.c
index dfce9ea..0a52d72 100644 (file)
--- a/drivers/infiniband/hw/nes/nes_cm.c
+++ b/drivers/infiniband/hw/nes/nes_cm.c
@@ -1377,9 +1377,11 @@ static int nes_addr_resolve_neigh(struct nes_vnic *nesvnic, u32 dst_ip, int arpi
                neigh_release(neigh);
        }
 
-       if ((neigh == NULL) || (!(neigh->nud_state & NUD_VALID)))
+       if ((neigh == NULL) || (!(neigh->nud_state & NUD_VALID))) {
+               rcu_read_lock();
                neigh_event_send(dst_get_neighbour(&rt->dst), NULL);
-
+               rcu_read_unlock();
+       }
        ip_rt_put(rt);
        return rc;
 }

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index 7567b60..ef38848 100644 (file)
--- 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 1b7a976..cad1894 100644 (file)
--- 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;