IB/core: Fix oops in netdev_next_upper_dev_rcu()

Mark Zhang · dledford · commit 37fbd834b4e4 · 2018-12-12T12:14:49.000-05:00
When support for bonding of RoCE devices was added, there was necessarily a link between the RoCE device and the paired netdevice that was part of the bond. If you remove the mlx4_en module, that paired association is broken (the RoCE device is still present but the paired netdevice has been released). We need to account for this in is_upper_ndev_bond_master_filter() and filter out those links with a broken pairing or else we later oops in netdev_next_upper_dev_rcu(). Fixes: 408f124 ("IB/core: Delete lower netdevice default GID entries in bonding scenario") Signed-off-by: Mark Zhang <markz@mellanox.com> Reviewed-by: Parav Pandit <parav@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/drivers/infiniband/core/roce_gid_mgmt.c b/drivers/infiniband/core/roce_gid_mgmt.c
@@ -267,6 +267,9 @@ is_upper_ndev_bond_master_filter(struct ib_device *ib_dev, u8 port,
 	struct net_device *cookie_ndev = cookie;
 	bool match = false;
 
+	if (!rdma_ndev)
+		return false;
+
 	rcu_read_lock();
 	if (netif_is_bond_master(cookie_ndev) &&
 	    rdma_is_upper_dev_rcu(rdma_ndev, cookie_ndev))
