================================================================== BUG: KCSAN: data-race in copy_process / free_pid read-write to 0xffffffff86860a20 of 4 bytes by task 3328 on cpu 0: free_pid+0x77/0x180 kernel/pid.c:126 free_pids+0x54/0xb0 kernel/pid.c:159 release_task+0x9a9/0xb60 kernel/exit.c:295 wait_task_zombie kernel/exit.c:1266 [inline] wait_consider_task+0x113f/0x1650 kernel/exit.c:1493 do_wait_thread kernel/exit.c:1556 [inline] __do_wait+0xfa/0x510 kernel/exit.c:1674 do_wait+0xb7/0x260 kernel/exit.c:1708 kernel_wait4+0x16b/0x1e0 kernel/exit.c:1867 __do_sys_wait4 kernel/exit.c:1895 [inline] __se_sys_wait4 kernel/exit.c:1891 [inline] __x64_sys_wait4+0x91/0x120 kernel/exit.c:1891 x64_sys_call+0x26c8/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:62 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffffffff86860a20 of 4 bytes by task 2 on cpu 1: copy_process+0x148f/0x1fe0 kernel/fork.c:2342 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 value changed: 0x800000c0 -> 0x800000bf Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 2 Comm: kthreadd Not tainted 6.15.0-syzkaller-11121-gfe4281644c62 #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 ==================================================================