9pnet_fd: Insufficient options for proto=fd
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BUG: KCSAN: data-race in pcpu_alloc / pcpu_balance_workfn

read-write to 0xffffffff86f41634 of 4 bytes by task 3124 on cpu 1:
 pcpu_update_empty_pages mm/percpu.c:602 [inline]
 pcpu_chunk_populated mm/percpu.c:1531 [inline]
 pcpu_balance_populated mm/percpu.c:2088 [inline]
 pcpu_balance_workfn+0x96f/0xa80 mm/percpu.c:2238
 process_one_work+0x3e6/0x750 kernel/workqueue.c:2390
 worker_thread+0x5f2/0xa10 kernel/workqueue.c:2537
 kthread+0x1a6/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

read to 0xffffffff86f41634 of 4 bytes by task 4869 on cpu 0:
 pcpu_alloc+0xa59/0x1280 mm/percpu.c:1870
 __alloc_percpu+0x24/0x30 mm/percpu.c:1943
 ipv4_mib_init_net+0x61/0x320 net/ipv4/af_inet.c:1755
 ops_init+0x1fc/0x2c0 net/core/net_namespace.c:135
 setup_net+0x2b5/0x700 net/core/net_namespace.c:338
 copy_net_ns+0x36c/0x500 net/core/net_namespace.c:490
 create_new_namespaces+0x228/0x430 kernel/nsproxy.c:110
 copy_namespaces+0x14d/0x1b0 kernel/nsproxy.c:179
 copy_process+0xf65/0x2100 kernel/fork.c:2267
 kernel_clone+0x169/0x560 kernel/fork.c:2679
 __do_sys_clone kernel/fork.c:2820 [inline]
 __se_sys_clone kernel/fork.c:2804 [inline]
 __x64_sys_clone+0xdf/0x110 kernel/fork.c:2804
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x00000001 -> 0x00000004

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 4869 Comm: syz-executor.1 Not tainted 6.3.0-rc5-syzkaller-00137-gf2afccfefe7b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023
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