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

read-write to 0xffffffff86c5ff68 of 4 bytes by task 12871 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
 __do_sys_clone3 kernel/fork.c:2955 [inline]
 __se_sys_clone3+0x1f5/0x230 kernel/fork.c:2934
 __x64_sys_clone3+0x31/0x40 kernel/fork.c:2934
 x64_sys_call+0x580/0x3020 arch/x86/include/generated/asm/syscalls_64.h:436
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff86c5ff68 of 4 bytes by task 2 on cpu 1:
 copy_process+0x187f/0x20b0 kernel/fork.c:2396
 kernel_clone+0x16b/0x5d0 kernel/fork.c:2653
 kernel_thread+0xe5/0x120 kernel/fork.c:2714
 create_kthread kernel/kthread.c:459 [inline]
 kthreadd+0x25b/0x320 kernel/kthread.c:817
 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: 0x80000137 -> 0x80000138

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 2 Comm: kthreadd Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
==================================================================