==================================================================
BUG: KCSAN: data-race in del_nbp / is_eth_port_of_netdev_filter

write to 0xffff88809b4ba22c of 4 bytes by task 22608 on cpu 0:
 del_nbp+0x72e/0x7b0 net/bridge/br_if.c:354
 br_dev_delete+0x5b/0xe0 net/bridge/br_if.c:375
 default_device_exit_batch+0x1ae/0x3e0 net/core/dev.c:10907
 ops_exit_list net/core/net_namespace.c:189 [inline]
 cleanup_net+0x4dc/0x8c0 net/core/net_namespace.c:603
 process_one_work+0x3e1/0x9a0 kernel/workqueue.c:2269
 worker_thread+0x665/0xbe0 kernel/workqueue.c:2415
 kthread+0x20d/0x230 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

read to 0xffff88809b4ba22c of 4 bytes by task 3249 on cpu 1:
 is_vlan_dev include/linux/if_vlan.h:74 [inline]
 rdma_vlan_dev_real_dev include/rdma/ib_addr.h:266 [inline]
 is_eth_port_of_netdev_filter+0x29/0x1a0 drivers/infiniband/core/roce_gid_mgmt.c:157
 ib_enum_roce_netdev+0x292/0x310 drivers/infiniband/core/device.c:2292
 ib_enum_all_roce_netdevs+0x94/0x100 drivers/infiniband/core/device.c:2321
 netdevice_event_work_handler+0xf8/0x200 drivers/infiniband/core/roce_gid_mgmt.c:623
 process_one_work+0x3e1/0x9a0 kernel/workqueue.c:2269
 worker_thread+0x665/0xbe0 kernel/workqueue.c:2415
 kthread+0x20d/0x230 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3249 Comm: kworker/u4:3 Not tainted 5.9.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: gid-cache-wq netdevice_event_work_handler
==================================================================