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BUG: KCSAN: data-race in copy_mm / percpu_counter_destroy_many

write to 0xffff88811f3ff7c8 of 8 bytes by task 13907 on cpu 0:
 __list_del include/linux/list.h:203 [inline]
 __list_del_entry include/linux/list.h:226 [inline]
 list_del include/linux/list.h:237 [inline]
 percpu_counter_destroy_many+0xc7/0x2b0 lib/percpu_counter.c:244
 __mmdrop+0x25a/0x3f0 kernel/fork.c:734
 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+0x186/0x2a0 kernel/sched/core.c:5139
 context_switch kernel/sched/core.c:5259 [inline]
 __schedule+0x85f/0xcd0 kernel/sched/core.c:6863
 preempt_schedule_common kernel/sched/core.c:7047 [inline]
 __cond_resched+0x4e/0x90 kernel/sched/core.c:7376
 might_resched include/linux/kernel.h:61 [inline]
 might_alloc include/linux/sched/mm.h:323 [inline]
 slab_pre_alloc_hook mm/slub.c:4899 [inline]
 slab_alloc_node mm/slub.c:5234 [inline]
 kmem_cache_alloc_noprof+0x5f/0x4b0 mm/slub.c:5265
 vm_area_alloc+0x2c/0xb0 mm/vma_init.c:32
 __mmap_new_vma mm/vma.c:2469 [inline]
 __mmap_region mm/vma.c:2708 [inline]
 mmap_region+0xadf/0x1410 mm/vma.c:2786
 do_mmap+0x9b3/0xbe0 mm/mmap.c:558
 vm_mmap_pgoff+0x17a/0x2e0 mm/util.c:581
 vm_mmap+0x88/0xb0 mm/util.c:617
 elf_map fs/binfmt_elf.c:399 [inline]
 elf_load+0x1a2/0x510 fs/binfmt_elf.c:422
 load_elf_interp+0x347/0x6e0 fs/binfmt_elf.c:689
 load_elf_binary+0x118d/0x1a20 fs/binfmt_elf.c:1254
 search_binary_handler fs/exec.c:1669 [inline]
 exec_binprm fs/exec.c:1701 [inline]
 bprm_execve+0x477/0x9b0 fs/exec.c:1753
 kernel_execve+0x617/0x660 fs/exec.c:1919
 call_usermodehelper_exec_async+0x197/0x250 kernel/umh.c:109
 ret_from_fork+0x149/0x290 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

read to 0xffff88811f3ff2c0 of 1664 bytes by task 13895 on cpu 1:
 dup_mm kernel/fork.c:1523 [inline]
 copy_mm+0xe2/0x370 kernel/fork.c:1581
 copy_process+0xcbc/0x1ef0 kernel/fork.c:2221
 kernel_clone+0x16c/0x5c0 kernel/fork.c:2651
 __do_sys_clone kernel/fork.c:2792 [inline]
 __se_sys_clone kernel/fork.c:2776 [inline]
 __x64_sys_clone+0xe6/0x120 kernel/fork.c:2776
 x64_sys_call+0x12d0/0x3000 arch/x86/include/generated/asm/syscalls_64.h:57
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd8/0x2a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 13895 Comm: dhcpcd-run-hook Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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