syzbot

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BUG: KCSAN: data-race in __dev_open / is_upper_ndev_bond_master_filter

write to 0xffff88809c091228 of 4 bytes by task 8728 on cpu 1:
 __dev_open+0x26b/0x340 net/core/dev.c:1522
 __dev_change_flags+0x167/0x3f0 net/core/dev.c:8278
 rtnl_configure_link+0xc2/0x150 net/core/rtnetlink.c:3021
 __rtnl_newlink net/core/rtnetlink.c:3357 [inline]
 rtnl_newlink+0xeba/0x1320 net/core/rtnetlink.c:3397
 rtnetlink_rcv_msg+0x71b/0x7b0 net/core/rtnetlink.c:5460
 netlink_rcv_skb+0x13e/0x240 net/netlink/af_netlink.c:2469
 rtnetlink_rcv+0x18/0x20 net/core/rtnetlink.c:5478
 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
 netlink_unicast+0x5e2/0x6b0 net/netlink/af_netlink.c:1329
 netlink_sendmsg+0x6d8/0x7a0 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0x360/0x4d0 net/socket.c:2352
 ___sys_sendmsg net/socket.c:2406 [inline]
 __sys_sendmsg+0x1df/0x260 net/socket.c:2439
 __do_sys_sendmsg net/socket.c:2448 [inline]
 __se_sys_sendmsg net/socket.c:2446 [inline]
 __x64_sys_sendmsg+0x42/0x50 net/socket.c:2446
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88809c091228 of 4 bytes by task 21 on cpu 0:
 netif_is_bond_master include/linux/netdevice.h:4774 [inline]
 is_upper_ndev_bond_master_filter+0x27/0xb0 drivers/infiniband/core/roce_gid_mgmt.c:274
 ib_enum_roce_netdev+0x292/0x310 drivers/infiniband/core/device.c:2284
 ib_enum_all_roce_netdevs+0x94/0x100 drivers/infiniband/core/device.c:2313
 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:291
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 21 Comm: kworker/u4:1 Not tainted 5.8.0-rc4-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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