net: hns3: put off calling register_netdev() until client initialize complete

In the Linux kernel, the following vulnerability has been resolved:

net: hns3: put off calling register_netdev() until client initialize complete

Currently, the netdevice is registered before client initializing

complete. So there is a timewindow between netdevice available

and usable. In this case, if user try to change the channel number

or ring param, it may cause the hns3_set_rx_cpu_rmap() being called

twice, and report bug.

[47199.416502] hns3 0000:35:00.0 eth1: set channels: tqp_num=1, rxfh=0

[47199.430340] hns3 0000:35:00.0 eth1: already uninitialized

[47199.438554] hns3 0000:35:00.0: rss changes from 4 to 1

[47199.511854] hns3 0000:35:00.0: Channels changed, rss_size from 4 to 1, tqps from 4 to 1

[47200.163524] ------------[ cut here ]------------

[47200.171674] kernel BUG at lib/cpu_rmap.c:142!

[47200.177847] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP

[47200.185259] Modules linked in: hclge(+) hns3(-) hns3_cae(O) hns_roce_hw_v2 hnae3 vfio_iommu_type1 vfio_pci vfio_virqfd vfio pv680_mii(O) [last unloaded: hclge]

[47200.205912] CPU: 1 PID: 8260 Comm: ethtool Tainted: G O 5.11.0-rc3+ #1

[47200.215601] Hardware name: , xxxxxx 02/04/2021

[47200.223052] pstate: 60400009 (nZCv daif +PAN -UAO -TCO BTYPE=--)

[47200.230188] pc : cpu_rmap_add+0x38/0x40

[47200.237472] lr : irq_cpu_rmap_add+0x84/0x140

[47200.243291] sp : ffff800010e93a30

[47200.247295] x29: ffff800010e93a30 x28: ffff082100584880

[47200.254155] x27: 0000000000000000 x26: 0000000000000000

[47200.260712] x25: 0000000000000000 x24: 0000000000000004

[47200.267241] x23: ffff08209ba03000 x22: ffff08209ba038c0

[47200.273789] x21: 000000000000003f x20: ffff0820e2bc1680

[47200.280400] x19: ffff0820c970ec80 x18: 00000000000000c0

[47200.286944] x17: 0000000000000000 x16: ffffb43debe4a0d0

[47200.293456] x15: fffffc2082990600 x14: dead000000000122

[47200.300059] x13: ffffffffffffffff x12: 000000000000003e

[47200.306606] x11: ffff0820815b8080 x10: ffff53e411988000

[47200.313171] x9 : 0000000000000000 x8 : ffff0820e2bc1700

[47200.319682] x7 : 0000000000000000 x6 : 000000000000003f

[47200.326170] x5 : 0000000000000040 x4 : ffff800010e93a20

[47200.332656] x3 : 0000000000000004 x2 : ffff0820c970ec80

[47200.339168] x1 : ffff0820e2bc1680 x0 : 0000000000000004

[47200.346058] Call trace:

[47200.349324] cpu_rmap_add+0x38/0x40

[47200.354300] hns3_set_rx_cpu_rmap+0x6c/0xe0 [hns3]

[47200.362294] hns3_reset_notify_init_enet+0x1cc/0x340 [hns3]

[47200.370049] hns3_change_channels+0x40/0xb0 [hns3]

[47200.376770] hns3_set_channels+0x12c/0x2a0 [hns3]

[47200.383353] ethtool_set_channels+0x140/0x250

[47200.389772] dev_ethtool+0x714/0x23d0

[47200.394440] dev_ioctl+0x4cc/0x640

[47200.399277] sock_do_ioctl+0x100/0x2a0

[47200.404574] sock_ioctl+0x28c/0x470

[47200.409079] __arm64_sys_ioctl+0xb4/0x100

[47200.415217] el0_svc_common.constprop.0+0x84/0x210

[47200.422088] do_el0_svc+0x28/0x34

[47200.426387] el0_svc+0x28/0x70

[47200.431308] el0_sync_handler+0x1a4/0x1b0

[47200.436477] el0_sync+0x174/0x180

[47200.441562] Code: 11000405 79000c45 f8247861 d65f03c0 (d4210000)

[47200.448869] ---[ end trace a01efe4ce42e5f34 ]---

The process is like below:

excuting hns3_client_init

|

register_netdev()

| hns3_set_channels()

| |

hns3_set_rx_cpu_rmap() hns3_reset_notify_uninit_enet()

| |

| quit without calling function

| hns3_free_rx_cpu_rmap for flag

| HNS3_NIC_STATE_INITED is unset.

| |

| hns3_reset_notify_init_enet()

| |

set HNS3_NIC_STATE_INITED call hns3_set_rx_cpu_rmap()-- crash

Fix it by calling register_netdev() at the end of function

hns3_client_init().