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BUG: KCSAN: data-race in css_set_move_task / memcpy_and_pad

write to 0xffff888104a34ee0 of 8 bytes by task 3287 on cpu 0:
 __list_del include/linux/list.h:241 [inline]
 __list_del_entry include/linux/list.h:264 [inline]
 list_del_init include/linux/list.h:333 [inline]
 css_set_move_task+0x1c1/0x380 kernel/cgroup/cgroup.c:911
 do_cgroup_task_dead kernel/cgroup/cgroup.c:7172 [inline]
 cgroup_task_dead+0x6f/0x2b0 kernel/cgroup/cgroup.c:7236
 finish_task_switch+0x270/0x340 kernel/sched/core.c:5415
 context_switch kernel/sched/core.c:5523 [inline]
 __schedule+0x79b/0xd20 kernel/sched/core.c:7270
 preempt_schedule_irq+0x2c/0x50 kernel/sched/core.c:7592
 raw_irqentry_exit_cond_resched+0x49/0x60 kernel/entry/common.c:145
 irqentry_exit_to_kernel_mode_preempt+0x2b/0x40 include/linux/irq-entry-common.h:468
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
 irqentry_exit+0x7d/0x610 kernel/entry/common.c:167
 sysvec_apic_timer_interrupt+0x44/0x80 arch/x86/kernel/apic/apic.c:1062
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
 preempt_count arch/x86/include/asm/preempt.h:37 [inline]
 get_ctx kernel/kcsan/core.c:206 [inline]
 check_access kernel/kcsan/core.c:758 [inline]
 __tsan_read8+0xbf/0x190 kernel/kcsan/core.c:1033
 __d_lookup_rcu+0xd1/0x2d0 fs/dcache.c:2523
 lookup_fast+0xa3/0x320 fs/namei.c:1854
 walk_component fs/namei.c:2278 [inline]
 link_path_walk+0x523/0xdd0 fs/namei.c:2656
 path_parentat fs/namei.c:2860 [inline]
 __filename_parentat+0x1ad/0x460 fs/namei.c:2884
 filename_parentat fs/namei.c:2902 [inline]
 filename_renameat2+0x187/0x6a0 fs/namei.c:6272
 __do_sys_rename fs/namei.c:6370 [inline]
 __se_sys_rename+0x4a/0x1c0 fs/namei.c:6366
 __x64_sys_rename+0x31/0x40 fs/namei.c:6366
 x64_sys_call+0x20fe/0x2550 arch/x86/include/generated/asm/syscalls_64.h:83
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888104a34500 of 3456 bytes by task 5904 on cpu 1:
 memcpy_and_pad+0x48/0x80 lib/string_helpers.c:1008
 arch_dup_task_struct+0x2c/0x40 arch/x86/kernel/process.c:108
 dup_task_struct+0x6d/0x750 kernel/fork.c:926
 copy_process+0x5a0/0x2340 kernel/fork.c:2133
 kernel_clone+0x1c0/0x5f0 kernel/fork.c:2766
 __do_sys_clone3 kernel/fork.c:3069 [inline]
 __se_sys_clone3+0x1f5/0x230 kernel/fork.c:3048
 __x64_sys_clone3+0x31/0x40 kernel/fork.c:3048
 x64_sys_call+0x437/0x2550 arch/x86/include/generated/asm/syscalls_64.h:436
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 5904 Comm: syz.5.692 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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