==================================================================
BUG: KCSAN: data-race in alloc_pid / copy_process

write to 0xffffffff85a77590 of 4 bytes by task 23641 on cpu 1:
 alloc_pid+0x392/0x5c0 kernel/pid.c:227
 copy_process+0x216a/0x3b50 kernel/fork.c:2029
 _do_fork+0xfe/0x6e0 kernel/fork.c:2366
 __do_sys_clone kernel/fork.c:2521 [inline]
 __se_sys_clone kernel/fork.c:2502 [inline]
 __x64_sys_clone+0x12b/0x160 kernel/fork.c:2502
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffffffff85a77590 of 4 bytes by task 2 on cpu 0:
 copy_process+0x2844/0x3b50 kernel/fork.c:2163
 _do_fork+0xfe/0x6e0 kernel/fork.c:2366
 kernel_thread+0xa4/0xd0 kernel/fork.c:2453
 create_kthread kernel/kthread.c:278 [inline]
 kthreadd+0x352/0x3f0 kernel/kthread.c:596
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 2 Comm: kthreadd Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 2 Comm: kthreadd Not tainted 5.4.0-rc3+ #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+0xf5/0x159 lib/dump_stack.c:113
 panic+0x210/0x640 kernel/panic.c:221
 kcsan_report.cold+0xc/0x10 kernel/kcsan/report.c:302
 __kcsan_setup_watchpoint+0x32e/0x4a0 kernel/kcsan/core.c:411
 __tsan_read4 kernel/kcsan/kcsan.c:35 [inline]
 __tsan_read4+0x2c/0x30 kernel/kcsan/kcsan.c:35
 copy_process+0x2844/0x3b50 kernel/fork.c:2163
 _do_fork+0xfe/0x6e0 kernel/fork.c:2366
 kernel_thread+0xa4/0xd0 kernel/fork.c:2453
 create_kthread kernel/kthread.c:278 [inline]
 kthreadd+0x352/0x3f0 kernel/kthread.c:596
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352
Kernel Offset: disabled
Rebooting in 86400 seconds..