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

read-write to 0xffffffff86c5ffa8 of 4 bytes by task 50 on cpu 0:
 alloc_pid+0x651/0x940 kernel/pid.c:321
 copy_process+0xf37/0x20b0 kernel/fork.c:2239
 kernel_clone+0x16b/0x5d0 kernel/fork.c:2653
 user_mode_thread+0x9c/0xd0 kernel/fork.c:2729
 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:3276 [inline]
 process_scheduled_works+0x513/0xa10 kernel/workqueue.c:3359
 worker_thread+0x58a/0x780 kernel/workqueue.c:3440
 kthread+0x22a/0x280 kernel/kthread.c:436
 ret_from_fork+0x150/0x360 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffffffff86c5ffa8 of 4 bytes by task 308 on cpu 1:
 copy_process+0x187f/0x20b0 kernel/fork.c:2396
 kernel_clone+0x16b/0x5d0 kernel/fork.c:2653
 user_mode_thread+0x9c/0xd0 kernel/fork.c:2729
 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:3276 [inline]
 process_scheduled_works+0x513/0xa10 kernel/workqueue.c:3359
 worker_thread+0x58a/0x780 kernel/workqueue.c:3440
 kthread+0x22a/0x280 kernel/kthread.c:436
 ret_from_fork+0x150/0x360 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x8000009b -> 0x8000009c

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 308 Comm: kworker/u8:6 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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