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

read-write to 0xffff88810d4b1b28 of 4 bytes by task 11142 on cpu 1:
 free_pid+0xb3/0x1b0 kernel/pid.c:124
 free_pids+0x9e/0xb0 kernel/pid.c:156
 release_task+0x9a7/0xb60 kernel/exit.c:295
 exit_notify kernel/exit.c:777 [inline]
 do_exit+0xda4/0x1530 kernel/exit.c:988
 do_group_exit+0xfe/0x140 kernel/exit.c:1119
 get_signal+0xe30/0xf20 kernel/signal.c:3037
 arch_do_signal_or_restart+0x96/0x480 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop+0x6f/0x820 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x232/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88810d4b1b28 of 4 bytes by task 11145 on cpu 0:
 copy_process+0x1af1/0x2370 kernel/fork.c:2442
 kernel_clone+0x1a5/0x5e0 kernel/fork.c:2721
 __do_sys_clone3 kernel/fork.c:3025 [inline]
 __se_sys_clone3+0x1f5/0x230 kernel/fork.c:3004
 __x64_sys_clone3+0x31/0x40 kernel/fork.c:3004
 x64_sys_call+0x580/0x3020 arch/x86/include/generated/asm/syscalls_64.h:436
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x80000004 -> 0x80000003

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 11145 Comm: syz.3.1784 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
==================================================================