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

read-write to 0xffffffff8685f2b0 of 4 bytes by task 2 on cpu 0:
 alloc_pid+0x539/0x720 kernel/pid.c:280
 copy_process+0xe0e/0x1f90 kernel/fork.c:2446
 kernel_clone+0x16c/0x5b0 kernel/fork.c:2845
 kernel_thread+0xac/0xe0 kernel/fork.c:2907
 create_kthread kernel/kthread.c:487 [inline]
 kthreadd+0x28d/0x360 kernel/kthread.c:847
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffffffff8685f2b0 of 4 bytes by task 3813 on cpu 1:
 copy_process+0x1790/0x1f90 kernel/fork.c:2588
 kernel_clone+0x16c/0x5b0 kernel/fork.c:2845
 user_mode_thread+0x7d/0xb0 kernel/fork.c:2923
 call_usermodehelper_exec_sync kernel/umh.c:132 [inline]
 call_usermodehelper_exec_work+0x7a/0x160 kernel/umh.c:163
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3319
 worker_thread+0x582/0x770 kernel/workqueue.c:3400
 kthread+0x486/0x510 kernel/kthread.c:464
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x800000b3 -> 0x800000b4

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3813 Comm: kworker/u8:10 Not tainted 6.15.0-rc7-syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_unbound call_usermodehelper_exec_work
==================================================================
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered forwarding state
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered forwarding state
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered forwarding state
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered forwarding state