RDMA: Add netdevice_tracker to ib_device_set_netdev()

This will cause an informative backtrace to print if the user of
ib_device_set_netdev() isn't careful about tearing down the ibdevice
before its the netdevice parent is destroyed. Such as like this:

  unregister_netdevice: waiting for vlan0 to become free. Usage count = 2
  leaked reference.
   ib_device_set_netdev+0x266/0x730
   siw_newlink+0x4e0/0xfd0
   nldev_newlink+0x35c/0x5c0
   rdma_nl_rcv_msg+0x36d/0x690
   rdma_nl_rcv+0x2ee/0x430
   netlink_unicast+0x543/0x7f0
   netlink_sendmsg+0x918/0xe20
   sock_sendmsg+0xcf/0x120
   ____sys_sendmsg+0x70d/0x8b0
   ___sys_sendmsg+0x11d/0x1b0
   __sys_sendmsg+0xfa/0x1d0
   do_syscall_64+0x35/0xb0
   entry_SYSCALL_64_after_hwframe+0x63/0xcd

This will help debug the issues syzkaller is seeing.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/0-v1-a7c81b3842ce+e5-netdev_tracker_jgg@nvidia.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index a1f4d53a4bb6..77dd9148815b 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -2203,6 +2203,7 @@ struct ib_port_data {
 	struct ib_port_cache cache;
 
 	struct net_device __rcu *netdev;
+	netdevice_tracker netdev_tracker;
 	struct hlist_node ndev_hash_link;
 	struct rdma_port_counter port_counter;
 	struct ib_port *sysfs;