Subject: CVE-2021-47400: net: hns3: do not allow call hns3_nic_net_open repeatedly

From: Greg Kroah-Hartman <[email-masked]>

Description
===========

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

net: hns3: do not allow call hns3_nic_net_open repeatedly

hns3_nic_net_open() is not allowed to called repeatly, but there
is no checking for this. When doing device reset and setup tc
concurrently, there is a small oppotunity to call hns3_nic_net_open
repeatedly, and cause kernel bug by calling napi_enable twice.

The calltrace information is like below:
[ 3078.222780] ------------[ cut here ]------------
[ 3078.230255] kernel BUG at net/core/dev.c:6991!
[ 3078.236224] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
[ 3078.243431] Modules linked in: hns3 hclgevf hclge hnae3 vfio_iommu_type1 vfio_pci vfio_virqfd vfio pv680_mii(O)
[ 3078.258880] CPU: 0 PID: 295 Comm: kworker/u8:5 Tainted: G           O      5.14.0-rc4+ #1
[ 3078.269102] Hardware name:  , BIOS KpxxxFPGA 1P B600 V181 08/12/2021
[ 3078.276801] Workqueue: hclge hclge_service_task [hclge]
[ 3078.288774] pstate: 60400009 (nZCv daif +PAN -UAO -TCO BTYPE=--)
[ 3078.296168] pc : napi_enable+0x80/0x84
tc qdisc sho[w  3d0e7v8 .e3t0h218 79] lr : hns3_nic_net_open+0x138/0x510 [hns3]

[ 3078.314771] sp : ffff8000108abb20
[ 3078.319099] x29: ffff8000108abb20 x28: 0000000000000000 x27: ffff0820a8490300
[ 3078.329121] x26: 0000000000000001 x25: ffff08209cfc6200 x24: 0000000000000000
[ 3078.339044] x23: ffff0820a8490300 x22: ffff08209cd76000 x21: ffff0820abfe3880
[ 3078.349018] x20: 0000000000000000 x19: ffff08209cd76900 x18: 0000000000000000
[ 3078.358620] x17: 0000000000000000 x16: ffffc816e1727a50 x15: 0000ffff8f4ff930
[ 3078.368895] x14: 0000000000000000 x13: 0000000000000000 x12: 0000259e9dbeb6b4
[ 3078.377987] x11: 0096a8f7e764eb40 x10: 634615ad28d3eab5 x9 : ffffc816ad8885b8
[ 3078.387091] x8 : ffff08209cfc6fb8 x7 : ffff0820ac0da058 x6 : ffff0820a8490344
[ 3078.396356] x5 : 0000000000000140 x4 : 0000000000000003 x3 : ffff08209cd76938
[ 3078.405365] x2 : 0000000000000000 x1 : 0000000000000010 x0 : ffff0820abfe38a0
[ 3078.414657] Call trace:
[ 3078.418517]  napi_enable+0x80/0x84
[ 3078.424626]  hns3_reset_notify_up_enet+0x78/0xd0 [hns3]
[ 3078.433469]  hns3_reset_notify+0x64/0x80 [hns3]
[ 3078.441430]  hclge_notify_client+0x68/0xb0 [hclge]
[ 3078.450511]  hclge_reset_rebuild+0x524/0x884 [hclge]
[ 3078.458879]  hclge_reset_service_task+0x3c4/0x680 [hclge]
[ 3078.467470]  hclge_service_task+0xb0/0xb54 [hclge]
[ 3078.475675]  process_one_work+0x1dc/0x48c
[ 3078.481888]  worker_thread+0x15c/0x464
[ 3078.487104]  kthread+0x160/0x170
[ 3078.492479]  ret_from_fork+0x10/0x18
[ 3078.498785] Code: c8027c81 35ffffa2 d50323bf d65f03c0 (d4210000)
[ 3078.506889] ---[ end trace 8ebe0340a1b0fb44 ]---

Once hns3_nic_net_open() is excute success, the flag
HNS3_NIC_STATE_DOWN will be cleared. So add checking for this
flag, directly return when HNS3_NIC_STATE_DOWN is no set.

The Linux kernel CVE team has assigned CVE-2021-47400 to this issue.

Affected and fixed versions
===========================

	Issue introduced in 5.0 with commit e888402789b9 and fixed in 5.4.151 with commit 5a31d4e73ada
	Issue introduced in 5.0 with commit e888402789b9 and fixed in 5.10.71 with commit f8ba689cb695
	Issue introduced in 5.0 with commit e888402789b9 and fixed in 5.14.10 with commit 3dac38bdce79
	Issue introduced in 5.0 with commit e888402789b9 and fixed in 5.15 with commit 5b09e88e1bf7

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2021-47400
will be updated if fixes are backported, please check that for the most
up to date information about this issue.

Affected files
==============

The file(s) affected by this issue are:
	drivers/net/ethernet/hisilicon/hns3/hns3_enet.c

Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/5a31d4e73ada8022427b69b10fd1f01a6a8d4b3d
	https://git.kernel.org/stable/c/f8ba689cb69523144d10606096ef686002dd7285
	https://git.kernel.org/stable/c/3dac38bdce7932901b9f0b71c62331852c809e61
	https://git.kernel.org/stable/c/5b09e88e1bf7fe86540fab4b5f3eece8abead39e