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BUG: KCSAN: data-race in del_nbp / is_eth_port_of_netdev_filter

read-write to 0xffff88810dc7322c of 4 bytes by task 13613 on cpu 0:
 del_nbp+0x723/0x7a0 net/bridge/br_if.c:354
 br_dev_delete+0x57/0xe0 net/bridge/br_if.c:375
 default_device_exit_batch+0x1ae/0x3d0 net/core/dev.c:11100
 ops_exit_list net/core/net_namespace.c:190 [inline]
 cleanup_net+0x4cc/0x8a0 net/core/net_namespace.c:604
 process_one_work+0x3e1/0x950 kernel/workqueue.c:2272
 worker_thread+0x635/0xb90 kernel/workqueue.c:2418
 kthread+0x1fd/0x220 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

read to 0xffff88810dc7322c of 4 bytes by task 320 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:2263
 ib_enum_all_roce_netdevs+0x94/0x100 drivers/infiniband/core/device.c:2292
 netdevice_event_work_handler+0xf8/0x200 drivers/infiniband/core/roce_gid_mgmt.c:626
 process_one_work+0x3e1/0x950 kernel/workqueue.c:2272
 worker_thread+0x635/0xb90 kernel/workqueue.c:2418
 kthread+0x1fd/0x220 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 320 Comm: kworker/u4:3 Not tainted 5.10.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: gid-cache-wq netdevice_event_work_handler
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