syzbot

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BUG: KCSAN: data-race in pcpu_alloc / pcpu_chunk_populated

write to 0xffffffff86043740 of 4 bytes by task 7226 on cpu 0:
 pcpu_update_empty_pages mm/percpu.c:575 [inline]
 pcpu_chunk_populated+0xed/0x110 mm/percpu.c:1483
 pcpu_balance_workfn+0xa06/0xc50 mm/percpu.c:1921
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

read to 0xffffffff86043740 of 4 bytes by task 7230 on cpu 1:
 pcpu_alloc+0x3b0/0xcf0 mm/percpu.c:1729
 __alloc_percpu_gfp+0x31/0x50 mm/percpu.c:1783
 fib6_nh_init+0x2d6/0xee0 net/ipv6/route.c:3474
 ip6_route_info_create+0x913/0xd40 net/ipv6/route.c:3657
 ip6_route_add+0x30/0xd0 net/ipv6/route.c:3697
 addrconf_prefix_route.isra.0+0x1e3/0x260 net/ipv6/addrconf.c:2396
 addrconf_add_linklocal+0x1b1/0x250 net/ipv6/addrconf.c:3192
 addrconf_addr_gen+0x1ff/0x230 net/ipv6/addrconf.c:3317
 addrconf_dev_config+0x1c0/0x280 net/ipv6/addrconf.c:3360
 addrconf_notify+0x1fa/0x1480 net/ipv6/addrconf.c:3595
 notifier_call_chain+0xd7/0x160 kernel/notifier.c:95
 __raw_notifier_call_chain kernel/notifier.c:396 [inline]
 raw_notifier_call_chain+0x37/0x50 kernel/notifier.c:403
 call_netdevice_notifiers_info+0x48/0xc0 net/core/dev.c:1749

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7230 Comm: syz-executor.3 Not tainted 5.3.0+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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