================================================================== BUG: KCSAN: data-race in memcpy_and_pad / rcu_tasks_trace_pregp_step write to 0xffff8881002114dc of 4 bytes by task 28 on cpu 0: rcu_tasks_trace_pertask_prep kernel/rcu/tasks.h:1784 [inline] rcu_tasks_trace_pregp_step+0x1ac/0x920 kernel/rcu/tasks.h:1828 rcu_tasks_wait_gp+0x8b/0x530 kernel/rcu/tasks.h:826 rcu_tasks_one_gp+0x7f6/0x8e0 kernel/rcu/tasks.h:622 rcu_tasks_kthread+0xf7/0x110 kernel/rcu/tasks.h:658 kthread+0x489/0x510 kernel/kthread.c:463 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 0xffff888100211080 of 3264 bytes by task 2 on cpu 1: memcpy_and_pad+0x48/0x80 lib/string_helpers.c:1007 arch_dup_task_struct+0x2c/0x40 arch/x86/kernel/process.c:98 dup_task_struct+0x83/0x6a0 kernel/fork.c:878 copy_process+0x399/0x2000 kernel/fork.c:2004 kernel_clone+0x16c/0x5c0 kernel/fork.c:2605 kernel_thread+0xac/0xe0 kernel/fork.c:2667 create_kthread kernel/kthread.c:486 [inline] kthreadd+0x28d/0x360 kernel/kthread.c:846 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 2 Comm: kthreadd Not tainted 6.17.0-rc2-syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 ==================================================================