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BUG: KCSAN: data-race in copy_mm / percpu_counter_destroy_many

write to 0xffff888104b3ea80 of 8 bytes by task 4935 on cpu 1:
 __list_del include/linux/list.h:241 [inline]
 __list_del_entry include/linux/list.h:264 [inline]
 list_del include/linux/list.h:275 [inline]
 percpu_counter_destroy_many+0xbd/0x320 lib/percpu_counter.c:244
 __mmdrop+0x1c9/0x340 kernel/fork.c:741
 mmdrop include/linux/sched/mm.h:55 [inline]
 mmdrop_sched include/linux/sched/mm.h:83 [inline]
 mmdrop_lazy_tlb_sched include/linux/sched/mm.h:110 [inline]
 finish_task_switch+0x296/0x340 kernel/sched/core.c:5415
 context_switch kernel/sched/core.c:5536 [inline]
 __schedule+0x79e/0xd20 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0x5b/0xa0 kernel/sched/core.c:7376
 do_nanosleep+0xc5/0x360 kernel/time/hrtimer.c:2436
 hrtimer_nanosleep+0xf2/0x290 kernel/time/hrtimer.c:2482
 common_nsleep+0x62/0x80 kernel/time/posix-timers.c:1360
 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1406 [inline]
 __se_sys_clock_nanosleep+0x223/0x260 kernel/time/posix-timers.c:1383
 __x64_sys_clock_nanosleep+0x55/0x70 kernel/time/posix-timers.c:1383
 x64_sys_call+0x244d/0x2550 arch/x86/include/generated/asm/syscalls_64.h:231
 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 0xffff888104b3e540 of 1664 bytes by task 4959 on cpu 0:
 dup_mm kernel/fork.c:1537 [inline]
 copy_mm+0xd1/0x350 kernel/fork.c:1595
 copy_process+0x108a/0x2360 kernel/fork.c:2311
 kernel_clone+0x1c0/0x5f0 kernel/fork.c:2771
 __do_sys_clone kernel/fork.c:2913 [inline]
 __se_sys_clone kernel/fork.c:2897 [inline]
 __x64_sys_clone+0x143/0x180 kernel/fork.c:2897
 x64_sys_call+0x2479/0x2550 arch/x86/include/generated/asm/syscalls_64.h:57
 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: 0 UID: 0 PID: 4959 Comm: dhcpcd-run-hook Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
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