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

read-write to 0xffffffff8685ffc8 of 4 bytes by task 21282 on cpu 1:
 free_pid+0xb9/0x1d0 kernel/pid.c:126
 free_pids+0x7a/0xb0 kernel/pid.c:159
 release_task+0x9a7/0xb60 kernel/exit.c:295
 exit_notify kernel/exit.c:777 [inline]
 do_exit+0xd91/0x15d0 kernel/exit.c:983
 call_usermodehelper_exec_async+0x247/0x250 kernel/umh.c:122
 ret_from_fork+0x149/0x290 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

read to 0xffffffff8685ffc8 of 4 bytes by task 1601 on cpu 0:
 copy_process+0x16d4/0x1ef0 kernel/fork.c:2394
 kernel_clone+0x16c/0x5c0 kernel/fork.c:2651
 user_mode_thread+0x7d/0xb0 kernel/fork.c:2727
 call_usermodehelper_exec_work+0x41/0x160 kernel/umh.c:171
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3340
 worker_thread+0x582/0x770 kernel/workqueue.c:3421
 kthread+0x489/0x510 kernel/kthread.c:463
 ret_from_fork+0x149/0x290 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

value changed: 0x80000142 -> 0x80000141

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 1601 Comm: kworker/u8:8 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound call_usermodehelper_exec_work
==================================================================
bridge0: port 1(bridge_slave_0) entered disabled state
bridge0: port 2(bridge_slave_1) entered disabled state
netdevsim netdevsim9 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim9 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim9 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim9 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0