================================================================== BUG: KCSAN: data-race in alloc_pid / copy_process read-write to 0xffffffff86860860 of 4 bytes by task 2 on cpu 0: alloc_pid+0x539/0x720 kernel/pid.c:281 copy_process+0xe0e/0x1fe0 kernel/fork.c:2185 kernel_clone+0x16c/0x5b0 kernel/fork.c:2599 kernel_thread+0xac/0xe0 kernel/fork.c:2661 create_kthread kernel/kthread.c:487 [inline] kthreadd+0x28d/0x360 kernel/kthread.c:847 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 read to 0xffffffff86860860 of 4 bytes by task 10382 on cpu 1: copy_process+0x148f/0x1fe0 kernel/fork.c:2342 kernel_clone+0x16c/0x5b0 kernel/fork.c:2599 user_mode_thread+0x7d/0xb0 kernel/fork.c:2677 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+0x4ce/0x9d0 kernel/workqueue.c:3321 worker_thread+0x582/0x770 kernel/workqueue.c:3402 kthread+0x486/0x510 kernel/kthread.c:464 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 value changed: 0x80000111 -> 0x80000112 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 10382 Comm: kworker/u8:62 Not tainted 6.16.0-rc3-syzkaller-00190-g67a993863163 #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events_unbound call_usermodehelper_exec_work ==================================================================