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

write to 0xffff88810743e090 of 8 bytes by task 7852 on cpu 0:
 do_wait+0x1f7/0x4c0 kernel/exit.c:1468
 kernel_wait4+0x146/0x230 kernel/exit.c:1617
 __do_sys_wait4+0xea/0x100 kernel/exit.c:1629
 __se_sys_wait4 kernel/exit.c:1625 [inline]
 __x64_sys_wait4+0x59/0x70 kernel/exit.c:1625
 do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88810743e090 of 8 bytes by task 1073 on cpu 1:
 check_hung_uninterruptible_tasks kernel/hung_task.c:197 [inline]
 watchdog+0x2b8/0x960 kernel/hung_task.c:289
 kthread+0x1cb/0x1f0 kernel/kthread.c:255
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 1073 Comm: khungtaskd Not tainted 5.6.0-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: 1073 Comm: khungtaskd Not tainted 5.6.0-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/0x187 lib/dump_stack.c:118
 panic+0x210/0x640 kernel/panic.c:221
 kcsan_report.cold+0xc/0xf kernel/kcsan/report.c:599
 kcsan_setup_watchpoint+0x3fb/0x440 kernel/kcsan/core.c:507
 check_hung_uninterruptible_tasks kernel/hung_task.c:197 [inline]
 watchdog+0x2b8/0x960 kernel/hung_task.c:289
 kthread+0x1cb/0x1f0 kernel/kthread.c:255
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352
Kernel Offset: disabled
Rebooting in 86400 seconds..