==================================================================
BUG: KCSAN: data-race in do_wait / watchdog

read to 0xffff8880a1ccb090 of 8 bytes by task 1066 on cpu 0:
 check_hung_uninterruptible_tasks kernel/hung_task.c:197 [inline]
 watchdog+0x2b1/0x960 kernel/hung_task.c:289
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

write to 0xffff8880a1ccb090 of 8 bytes by task 8074 on cpu 1:
 do_wait+0x1f9/0x4c0 kernel/exit.c:1464
 kernel_wait4+0x156/0x240 kernel/exit.c:1613
 __do_sys_wait4+0xea/0x100 kernel/exit.c:1625
 __se_sys_wait4 kernel/exit.c:1621 [inline]
 __x64_sys_wait4+0x5e/0x80 kernel/exit.c:1621
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8074 Comm: syz-executor.5 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 8074 Comm: syz-executor.5 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x11d/0x181 lib/dump_stack.c:118
 panic+0x210/0x640 kernel/panic.c:221
 kcsan_report.cold+0xc/0xd kernel/kcsan/report.c:313
 kcsan_setup_watchpoint+0x3fe/0x460 kernel/kcsan/core.c:416
 check_access kernel/kcsan/core.c:459 [inline]
 __tsan_unaligned_write8+0xc7/0x110 kernel/kcsan/core.c:589
 do_wait+0x1f9/0x4c0 kernel/exit.c:1464
 kernel_wait4+0x156/0x240 kernel/exit.c:1613
 __do_sys_wait4+0xea/0x100 kernel/exit.c:1625
 __se_sys_wait4 kernel/exit.c:1621 [inline]
 __x64_sys_wait4+0x5e/0x80 kernel/exit.c:1621
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x41475a
Code: 0f 83 6a 18 00 00 c3 66 0f 1f 84 00 00 00 00 00 8b 05 1e 3d 66 00 85 c0 75 36 45 31 d2 48 63 d2 48 63 ff b8 3d 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 d4 ff ff ff f7
RSP: 002b:00007ffda2b89a48 EFLAGS: 00000246 ORIG_RAX: 000000000000003d
RAX: ffffffffffffffda RBX: 00000000002db435 RCX: 000000000041475a
RDX: 0000000040000001 RSI: 00007ffda2b89a80 RDI: ffffffffffffffff
RBP: 000000000000344e R08: 0000000000000001 R09: 00000000015c5940
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000a
R13: 00007ffda2b89a80 R14: 00000000002db3a1 R15: 00007ffda2b89a90
Kernel Offset: disabled
Rebooting in 86400 seconds..