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>
diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 3409c55..ff35ceb 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -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;
}
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index a1f4d53..77dd914 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;
