syzbot

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BUG: KCSAN: data-race in del_nbp / is_eth_port_of_netdev_filter

read-write to 0xffff88801e54f22c of 4 bytes by task 20436 on cpu 0:
 del_nbp+0x715/0x7d0 net/bridge/br_if.c:355
 br_dev_delete+0x57/0xe0 net/bridge/br_if.c:376
 rtnl_delete_link net/core/rtnetlink.c:3056 [inline]
 rtnl_dellink+0x355/0x6b0 net/core/rtnetlink.c:3109
 rtnetlink_rcv_msg+0x723/0x7c0 net/core/rtnetlink.c:5564
 netlink_rcv_skb+0x13e/0x240 net/netlink/af_netlink.c:2494
 rtnetlink_rcv+0x18/0x20 net/core/rtnetlink.c:5582
 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
 netlink_unicast+0x5df/0x6b0 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x6f8/0x7c0 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0x352/0x4c0 net/socket.c:2345
 ___sys_sendmsg net/socket.c:2399 [inline]
 __sys_sendmsg+0x1ed/0x270 net/socket.c:2432
 __do_sys_sendmsg net/socket.c:2441 [inline]
 __se_sys_sendmsg net/socket.c:2439 [inline]
 __x64_sys_sendmsg+0x42/0x50 net/socket.c:2439
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88801e54f22c of 4 bytes by task 27 on cpu 1:
 is_vlan_dev include/linux/if_vlan.h:74 [inline]
 rdma_vlan_dev_real_dev include/rdma/ib_addr.h:267 [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:2287
 ib_enum_all_roce_netdevs+0x94/0x100 drivers/infiniband/core/device.c:2316
 netdevice_event_work_handler+0xf8/0x200 drivers/infiniband/core/roce_gid_mgmt.c:626
 process_one_work+0x3e1/0x950 kernel/workqueue.c:2275
 worker_thread+0x635/0xb90 kernel/workqueue.c:2421
 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: 27 Comm: kworker/u4:2 Not tainted 5.10.0-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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