Commit 09f530f0 authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Leon Romanovsky
Browse files

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: default avatarJason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/0-v1-a7c81b3842ce+e5-netdev_tracker_jgg@nvidia.com


Signed-off-by: default avatarLeon Romanovsky <leon@kernel.org>
parent 0edf42cb

drivers/infiniband/core/device.c

+4 −2
Original line number Diff line number Diff line
@@ -2159,14 +2159,16 @@ int ib_device_set_netdev(struct ib_device *ib_dev, struct net_device *ndev, 
		return 0;

	}



	if (old_ndev)

		netdev_tracker_free(ndev, &pdata->netdev_tracker);

	if (ndev)

		dev_hold(ndev);

		netdev_hold(ndev, &pdata->netdev_tracker, GFP_ATOMIC);

	rcu_assign_pointer(pdata->netdev, ndev);

	spin_unlock_irqrestore(&pdata->netdev_lock, flags);



	add_ndev_hash(pdata);

	if (old_ndev)

		dev_put(old_ndev);

		__dev_put(old_ndev);



	return 0;

}

include/rdma/ib_verbs.h

+1 −0
Original line number Diff line number Diff line
@@ -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;