syzbot

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BUG: KCSAN: data-race in do_exit / zap_pid_ns_processes

write to 0xffff888107cee820 of 4 bytes by task 31247 on cpu 1:
 reparent_leader kernel/exit.c:669 [inline]
 forget_original_parent kernel/exit.c:721 [inline]
 exit_notify kernel/exit.c:737 [inline]
 do_exit+0xa61/0x17f0 kernel/exit.c:958
 do_group_exit+0x102/0x150 kernel/exit.c:1087
 get_signal+0xeb9/0x1000 kernel/signal.c:3017
 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x62/0x120 kernel/entry/common.c:218
 do_syscall_64+0xd6/0x1c0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888107cee820 of 4 bytes by task 31248 on cpu 0:
 thread_group_leader include/linux/sched/signal.h:701 [inline]
 zap_pid_ns_processes+0x3d/0x2c0 kernel/pid_namespace.c:175
 find_child_reaper kernel/exit.c:611 [inline]
 forget_original_parent kernel/exit.c:700 [inline]
 exit_notify kernel/exit.c:737 [inline]
 do_exit+0x155d/0x17f0 kernel/exit.c:958
 __do_sys_exit kernel/exit.c:1054 [inline]
 __se_sys_exit kernel/exit.c:1052 [inline]
 __x64_sys_exit+0x1f/0x20 kernel/exit.c:1052
 x64_sys_call+0x2da1/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:61
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000000 -> 0x00000011

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 31248 Comm: syz.0.8419 Not tainted 6.13.0-rc6-syzkaller-00036-gfbfd64d25c7a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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