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BUG: KCSAN: data-race in pcpu_alloc_noprof / pcpu_block_update_hint_alloc

read-write to 0xffffffff8841e6ac of 4 bytes by task 3110 on cpu 1:
 pcpu_update_empty_pages mm/percpu.c:602 [inline]
 pcpu_block_update_hint_alloc+0x5db/0x6a0 mm/percpu.c:923
 pcpu_alloc_area+0x488/0x4b0 mm/percpu.c:1258
 pcpu_alloc_noprof+0x4b3/0x10c0 mm/percpu.c:1834
 init_sctp_mibs net/sctp/protocol.c:1232 [inline]
 sctp_defaults_init+0x32e/0x540 net/sctp/protocol.c:1402
 ops_init+0x1ef/0x2b0 net/core/net_namespace.c:139
 setup_net+0x2ea/0x7c0 net/core/net_namespace.c:343
 copy_net_ns+0x37b/0x510 net/core/net_namespace.c:508
 create_new_namespaces+0x228/0x430 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xe6/0x120 kernel/nsproxy.c:228
 ksys_unshare+0x3da/0x720 kernel/fork.c:3323
 __do_sys_unshare kernel/fork.c:3394 [inline]
 __se_sys_unshare kernel/fork.c:3392 [inline]
 __x64_sys_unshare+0x1f/0x30 kernel/fork.c:3392
 x64_sys_call+0x2ca9/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:273
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f