hns3: ring buffer race leads can cause corruption

[dann frazier]

[Impact]
Memory corruption, which has been observed to lead to an Oops.

[Test Case]
iperf can trigger the oops, but it is very difficult to hit.

[Fix]
108ebb12d81c2 net: hns3: fix data race between ring->next_to_clean

[Regression Risk]
Fix is local to a single driver. Because we're adding a barrier, it comes with some performance impact risk.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-bionic' to 'verification-done-bionic'. If the problem still exists, change the tag 'verification-needed-bionic' to 'verification-failed-bionic'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[dann frazier (dannf)]

Proposed kernel regression tested w/ a 10 minute iperf run.

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 4.15.0-65.74

---------------
linux (4.15.0-65.74) bionic; urgency=medium

  * bionic/linux: 4.15.0-65.74 -proposed tracker (LP: #1844403)

  * arm64: large modules fail to load (LP: #1841109)
    - arm64/kernel: kaslr: reduce module randomization range to 4 GB
    - arm64/kernel: don't ban ADRP to work around Cortex-A53 erratum #843419
    - arm64: fix undefined reference to 'printk'
    - arm64/kernel: rename module_emit_adrp_veneer->module_emit_veneer_for_adrp
    - [config] Remove CONFIG_ARM64_MODULE_CMODEL_LARGE

  * CVE-2018-20976
    - xfs: clear sb->s_fs_info on mount failure

  * br_netfilter: namespace sysctl operations (LP: #1836910)
    - net: bridge: add bitfield for options and convert vlan opts
    - net: bridge: convert nf call options to bits
    - netfilter: bridge: port sysctls to use brnf_net
    - netfilter: bridge: namespace bridge netfilter sysctls
    - netfilter: bridge: prevent UAF in brnf_exit_net()

  * tuntap: correctly set SOCKWQ_ASYNC_NOSPACE (LP: #1830756)
    - tuntap: correctly set SOCKWQ_ASYNC_NOSPACE

  * Bionic update: upstream stable patchset 2019-08-30 (LP: #1842114)
    - HID: Add 044f:b320 ThrustMaster, Inc. 2 in 1 DT
    - MIPS: kernel: only use i8253 clocksource with periodic clockevent
    - mips: fix cacheinfo
    - netfilter: ebtables: fix a memory leak bug in compat
    - ASoC: dapm: Fix handling of custom_stop_condition on DAPM graph walks
    - bonding: Force slave speed check after link state recovery for 802.3ad
    - can: dev: call netif_carrier_off() in register_candev()
    - ASoC: Fail card instantiation if DAI format setup fails
    - st21nfca_connectivity_event_received: null check the allocation
    - st_nci_hci_connectivity_event_received: null check the allocation
    - ASoC: ti: davinci-mcasp: Correct slot_width posed constraint
    - net: usb: qmi_wwan: Add the BroadMobi BM818 card
    - qed: RDMA - Fix the hw_ver returned in device attributes
    - isdn: mISDN: hfcsusb: Fix possible null-pointer dereferences in
      start_isoc_chain()
    - netfilter: ipset: Fix rename concurrency with listing
    - isdn: hfcsusb: Fix mISDN driver crash caused by transfer buffer on the stack
    - perf bench numa: Fix cpu0 binding
    - can: sja1000: force the string buffer NULL-terminated
    - can: peak_usb: force the string buffer NULL-terminated
    - net/ethernet/qlogic/qed: force the string buffer NULL-terminated
    - NFSv4: Fix a potential sleep while atomic in nfs4_do_reclaim()
    - HID: input: fix a4tech horizontal wheel custom usage
    - SMB3: Kernel oops mounting a encryptData share with CONFIG_DEBUG_VIRTUAL
    - net: cxgb3_main: Fix a resource leak in a error path in 'init_one()'
    - net: hisilicon: make hip04_tx_reclaim non-reentrant
    - net: hisilicon: fix hip04-xmit never return TX_BUSY
    - net: hisilicon: Fix dma_map_single failed on arm64
    - libata: have ata_scsi_rw_xlat() fail invalid passthrough requests
    - libata: add SG safety checks in SFF pio transfers
    - x86/lib/cpu: Address missing prototypes warning
    - drm/vmwgfx: fix memory leak when too many retries have occurred
    - perf ftrace: Fix failure to set cpuma...