IPVS: ftp: loaded support on port[0] = 21
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BUG: KCSAN: data-race in pcpu_alloc / pcpu_balance_workfn

write to 0xffffffff88f40ccc of 4 bytes by task 7 on cpu 0:
 pcpu_update_empty_pages mm/percpu.c:559 [inline]
 pcpu_chunk_populated mm/percpu.c:1493 [inline]
 __pcpu_balance_workfn mm/percpu.c:2033 [inline]
 pcpu_balance_workfn+0xc7c/0xe40 mm/percpu.c:2069
 process_one_work+0x3e1/0x950 kernel/workqueue.c:2275
 worker_thread+0x616/0xa70 kernel/workqueue.c:2421
 kthread+0x20b/0x230 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

read to 0xffffffff88f40ccc of 4 bytes by task 11519 on cpu 1:
 pcpu_alloc+0xaed/0x1090 mm/percpu.c:1835
 __alloc_percpu+0x20/0x30 mm/percpu.c:1907
 ipv6_init_mibs net/ipv6/af_inet6.c:890 [inline]
 inet6_net_init+0x1fd/0x460 net/ipv6/af_inet6.c:963
 ops_init+0x1e7/0x230 net/core/net_namespace.c:140
 setup_net+0x1eb/0x740 net/core/net_namespace.c:333
 copy_net_ns+0x2a9/0x450 net/core/net_namespace.c:474
 create_new_namespaces+0x231/0x560 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xe2/0x120 kernel/nsproxy.c:226
 ksys_unshare+0x373/0x6a0 kernel/fork.c:2994
 __do_sys_unshare kernel/fork.c:3062 [inline]
 __se_sys_unshare kernel/fork.c:3060 [inline]
 __x64_sys_unshare+0x1b/0x20 kernel/fork.c:3060
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 11519 Comm: syz-executor.3 Not tainted 5.12.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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