==================================================================
BUG: KCSAN: data-race in rcu_gp_fqs_check_wake / rcu_preempt_deferred_qs_irqrestore

write to 0xffffffff85c7d190 of 8 bytes by task 9964 on cpu 0:
 rcu_preempt_deferred_qs_irqrestore+0x43d/0x580 kernel/rcu/tree_plugin.h:496
 rcu_read_unlock_special kernel/rcu/tree_plugin.h:644 [inline]
 __rcu_read_unlock+0x16a/0x3d0 kernel/rcu/tree_plugin.h:383
 rcu_read_unlock include/linux/rcupdate.h:670 [inline]
 __atomic_notifier_call_chain kernel/notifier.c:174 [inline]
 atomic_notifier_call_chain+0x44/0x60 kernel/notifier.c:183
 inet6addr_notifier_call_chain+0x2e/0x40 net/ipv6/addrconf_core.c:109
 addrconf_ifdown+0x6b7/0xce0 net/ipv6/addrconf.c:3823
 addrconf_notify+0x35e/0x1550 net/ipv6/addrconf.c:3633
 notifier_call_chain+0xd7/0x160 kernel/notifier.c:83
 __raw_notifier_call_chain kernel/notifier.c:361 [inline]
 raw_notifier_call_chain+0x37/0x50 kernel/notifier.c:368
 call_netdevice_notifiers_info net/core/dev.c:1893 [inline]
 call_netdevice_notifiers_info+0x9a/0x120 net/core/dev.c:1878
 call_netdevice_notifiers_extack net/core/dev.c:1905 [inline]
 call_netdevice_notifiers net/core/dev.c:1919 [inline]
 dev_close_many+0x24f/0x380 net/core/dev.c:1544
 rollback_registered_many+0x2f5/0xa40 net/core/dev.c:8721
 rollback_registered+0xd2/0x160 net/core/dev.c:8789
 unregister_netdevice_queue net/core/dev.c:9888 [inline]
 unregister_netdevice_queue+0x199/0x2e0 net/core/dev.c:9881
 unregister_netdevice include/linux/netdevice.h:2674 [inline]
 __tun_detach+0xad3/0xb90 drivers/net/tun.c:723
 tun_detach drivers/net/tun.c:740 [inline]
 tun_chr_close+0x71/0xb0 drivers/net/tun.c:3455
 __fput+0x1e1/0x520 fs/file_table.c:280
 ____fput+0x1f/0x30 fs/file_table.c:313
 task_work_run+0xf6/0x130 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x2b4/0x2c0 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x384/0x3a0 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffffffff85c7d190 of 8 bytes by task 10 on cpu 1:
 rcu_gp_fqs_check_wake kernel/rcu/tree.c:1606 [inline]
 rcu_gp_fqs_check_wake+0x93/0xd0 kernel/rcu/tree.c:1596
 rcu_gp_fqs_loop+0x36c/0x580 kernel/rcu/tree.c:1661
 rcu_gp_kthread+0x143/0x230 kernel/rcu/tree.c:1821
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 10 Comm: rcu_preempt Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================