syzbot

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BUG: KCSAN: data-race in rcu_gp_fqs_check_wake kernel/rcu/tree.c:1556 [inline] and rcu_preempt_deferred_qs_irqrestore+0x43d/0x580
BUG: KCSAN: data-race in rcu_gp_fqs_check_wake+0x93/0xd0 kernel/rcu/tree.c:1546 and rcu_preempt_deferred_qs_irqrestore+0x43d/0x580

write to 0xffffffff85a7f190 of 8 bytes by task 7230 on cpu 1:
 rcu_preempt_deferred_qs_irqrestore+0x43d/0x580 kernel/rcu/tree_plugin.h:507
 rcu_read_unlock_special+0xec/0x370 kernel/rcu/tree_plugin.h:659
 __rcu_read_unlock+0xcf/0xe0 kernel/rcu/tree_plugin.h:394
 rcu_read_unlock include/linux/rcupdate.h:645 [inline]
 sock_def_readable+0xd5/0x140 net/core/sock.c:2789
 unix_dgram_sendmsg+0x92a/0xc80 net/unix/af_unix.c:1752
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0x9f/0xc0 net/socket.c:657
 __sys_sendto+0x21f/0x320 net/socket.c:1952
 __do_sys_sendto net/socket.c:1964 [inline]
 __se_sys_sendto net/socket.c:1960 [inline]
 __x64_sys_sendto+0x89/0xb0 net/socket.c:1960
 do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffffffff85a7f190 of 8 bytes by task 10 on cpu 0:
 rcu_gp_fqs_check_wake kernel/rcu/tree.c:1556 [inline]
 rcu_gp_fqs_check_wake+0x93/0xd0 kernel/rcu/tree.c:1546
 rcu_gp_fqs_loop+0x1df/0x580 kernel/rcu/tree.c:1611
 rcu_gp_kthread+0x143/0x220 kernel/rcu/tree.c:1768
 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: 0 PID: 10 Comm: rcu_preempt Not tainted 5.3.0+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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