================================================================== BUG: KCSAN: data-race in copy_process / free_pid read-write to 0xffffffff868608e0 of 4 bytes by task 31067 on cpu 0: free_pid+0x77/0x180 kernel/pid.c:126 free_pids+0x7a/0xb0 kernel/pid.c:159 release_task+0x9a9/0xb60 kernel/exit.c:295 exit_notify kernel/exit.c:782 [inline] do_exit+0xd81/0x1590 kernel/exit.c:976 call_usermodehelper_exec_async+0x247/0x250 kernel/umh.c:122 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 0xffffffff868608e0 of 4 bytes by task 10480 on cpu 1: copy_process+0x1790/0x1f90 kernel/fork.c:2342 kernel_clone+0x16c/0x5b0 kernel/fork.c:2599 user_mode_thread+0x7d/0xb0 kernel/fork.c:2677 call_usermodehelper_exec_work+0x41/0x160 kernel/umh.c:171 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3321 worker_thread+0x582/0x770 kernel/workqueue.c:3402 kthread+0x489/0x510 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: 0x800000f6 -> 0x800000f5 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 10480 Comm: kworker/u8:9 Not tainted 6.16.0-rc5-syzkaller-00266-g3f31a806a62e #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events_unbound call_usermodehelper_exec_work ==================================================================