syzbot

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BUG: KCSAN: data-race in copy_process / free_pid

read-write to 0xffffffff8605c618 of 4 bytes by task 8920 on cpu 0:
 free_pid+0x80/0x170 kernel/pid.c:143
 copy_process+0x19c5/0x1f80 kernel/fork.c:2636
 kernel_clone+0x16a/0x570 kernel/fork.c:2796
 __do_sys_clone3 kernel/fork.c:3097 [inline]
 __se_sys_clone3+0x1b5/0x1f0 kernel/fork.c:3081
 __x64_sys_clone3+0x31/0x40 kernel/fork.c:3081
 x64_sys_call+0x1538/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:436
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff8605c618 of 4 bytes by task 5659 on cpu 1:
 copy_process+0x15d8/0x1f80 kernel/fork.c:2542
 kernel_clone+0x16a/0x570 kernel/fork.c:2796
 user_mode_thread+0x7d/0xb0 kernel/fork.c:2874
 call_usermodehelper_exec_work+0x41/0x150 kernel/umh.c:172
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0x465/0x990 kernel/workqueue.c:3335
 worker_thread+0x526/0x730 kernel/workqueue.c:3416
 kthread+0x1d1/0x210 kernel/kthread.c:388
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

value changed: 0x80000214 -> 0x80000213

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 5659 Comm: kworker/u8:7 Not tainted 6.9.0-rc4-syzkaller-00031-g96fca68c4fbf #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: events_unbound call_usermodehelper_exec_work
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