syzbot

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BUG: KCSAN: data-race in copy_process / free_pid

read-write to 0xffff88811229c688 of 4 bytes by task 7803 on cpu 1:
 free_pid+0x71/0x180 kernel/pid.c:136
 copy_process+0x1924/0x20e0 kernel/fork.c:2488
 kernel_clone+0x163/0x5c0 kernel/fork.c:2642
 __do_sys_clone kernel/fork.c:2759 [inline]
 __se_sys_clone kernel/fork.c:2743 [inline]
 __x64_sys_clone+0xbd/0xf0 kernel/fork.c:2743
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

read to 0xffff88811229c688 of 4 bytes by task 7804 on cpu 0:
 copy_process+0x1528/0x20e0 kernel/fork.c:2402
 kernel_clone+0x163/0x5c0 kernel/fork.c:2642
 __do_sys_clone kernel/fork.c:2759 [inline]
 __se_sys_clone kernel/fork.c:2743 [inline]
 __x64_sys_clone+0xbd/0xf0 kernel/fork.c:2743
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

value changed: 0x8000001e -> 0x8000001d

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7804 Comm: syz-executor.4 Not tainted 5.18.0-syzkaller-11538-ge1cbc3b96a99-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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