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BUG: KCSAN: data-race in pcpu_alloc / pcpu_free_area

read-write to 0xffffffff884054dc of 4 bytes by task 54 on cpu 0:
 pcpu_update_empty_pages mm/percpu.c:602 [inline]
 pcpu_block_update_hint_free mm/percpu.c:1044 [inline]
 pcpu_free_area+0x4e2/0x570 mm/percpu.c:1302
 free_percpu+0x1c6/0xb30 mm/percpu.c:2303
 htab_free_elems kernel/bpf/hashtab.c:284 [inline]
 prealloc_destroy+0xea/0x1a0 kernel/bpf/hashtab.c:379
 htab_map_free+0x4a2/0x620 kernel/bpf/hashtab.c:1548
 bpf_map_free_deferred+0xae/0x150 kernel/bpf/syscall.c:734
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0x465/0x990 kernel/workqueue.c:3335
 worker_thread+0x526/0x730 kernel/workqueue.c:3416
 kthread+0x1d1/0x210 kernel/kthread.c:388
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

read to 0xffffffff884054dc of 4 bytes by task 3633 on cpu 1:
 pcpu_alloc+0x9aa/0x10d0 mm/percpu.c:1868
 __alloc_percpu_gfp+0x26/0x30 mm/percpu.c:1930
 bpf_map_alloc_percpu+0xab/0x200 kernel/bpf/syscall.c:466
 prealloc_init+0x19f/0x470 kernel/bpf/hashtab.c:338
 htab_map_alloc+0x637/0x8f0 kernel/bpf/hashtab.c:573
 map_create+0x83c/0xb90 kernel/bpf/syscall.c:1320
 __sys_bpf+0x667/0x7a0 kernel/bpf/syscall.c:5642
 __do_sys_bpf kernel/bpf/syscall.c:5767 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5765 [inline]
 __x64_sys_bpf+0x43/0x50 kernel/bpf/syscall.c:5765
 x64_sys_call+0x86c/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:322
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000059 -> 0x00000061

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3633 Comm: syz-executor.1 Not tainted 6.9.0-rc6-syzkaller-00005-gb947cc5bf6d7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
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