linux-azure-cvm: Avoid leaking guest memory when communicating with the host

[Marcelo Cerri]

[Impact]

Initialize memory of request offers message to be sent to the host so
padding or uninitialized fields do not leak guest memory contents.

Patch:

https://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux.git/commit/?h=hyperv-next

[Test case]

Testing the information leakage to the host is not viable, but since the patch the vmbus layer that affects all the hyper-v drivers, a boot test on Hyper-V and on Azure should be enough to validate the patch, considering how small the change is.

[Potential regression]

The change is very restricted, but on an eventual regression it might affect any of the hyperv guest drivers.

[Marcelo Cerri (mhcerri)]

Patch submission: https://lists.ubuntu.com/archives/kernel-team/2022-January/127030.html

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

This bug is awaiting verification that the linux-azure-cvm/5.4.0-1068.71+cvm1 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-focal' to 'verification-done-focal'. If the problem still exists, change the tag 'verification-needed-focal' to 'verification-failed-focal'.

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!

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux-azure-cvm - 5.4.0-1068.71+cvm1

---------------
linux-azure-cvm (5.4.0-1068.71+cvm1) focal; urgency=medium

  * focal/linux-azure-cvm: 5.4.0-1068.71+cvm1 -proposed tracker (LP: #1955216)

  * linux-azure-cvm: Avoid leaking guest memory when communicating with the host
    (LP: #1956793)
    - SAUCE: Drivers: hv: vmbus: Initialize request offers message for Isolation
      VM

  [ Ubuntu: 5.4.0-1068.71 ]

  * focal/linux-azure: 5.4.0-1068.71 -proposed tracker (LP: #1955219)
  * icmp_redirect from selftests fails on F/kvm (unary operator expected)
    (LP: #1938964)
    - selftests: icmp_redirect: pass xfail=0 to log_test()
  * Focal: CIFS stable updates (LP: #1954926)
    - cifs: use the expiry output of dns_query to schedule next resolution
    - cifs: set a minimum of 120s for next dns resolution
    - cifs: To match file servers, make sure the server hostname matches
  * seccomp_bpf in seccomp from ubuntu_kernel_selftests failed to build on B-5.4
    (LP: #1896420)
    - SAUCE: selftests/seccomp: fix "storage size of 'md' isn't known" build issue
    - SAUCE: selftests/seccomp: Fix s390x regs not defined issue
  * system crash when removing ipmi_msghandler module (LP: #1950666)
    - ipmi: Move remove_work to dedicated workqueue
    - ipmi: msghandler: Make symbol 'remove_work_wq' static
  * zcrypt DD: Toleration for new IBM Z Crypto Hardware - (Backport to Ubuntu
    20.04) (LP: #1954680)
    - s390/AP: support new dynamic AP bus size limit
  * [UBUNTU 20.04] KVM hardware diagnose data improvements for guest kernel -
    kernel part (LP: #1953334)
    - s390/setup: diag 318: refactor struct
    - s390/kvm: diagnose 0x318 sync and reset
    - KVM: s390: remove diag318 reset code
    - KVM: s390: add debug statement for diag 318 CPNC data
  * Updates to ib_peer_memory requested by Nvidia (LP: #1947206)
    - SAUCE: RDMA/core: Updated ib_peer_memory
  * Include Infiniband Peer Memory interface (LP: #1923104)
    - IB: Allow calls to ib_umem_get from kernel ULPs
    - SAUCE: RDMA/core: Introduce peer memory interface
  * Focal update: v5.4.162 upstream stable release (LP: #1954834)
    - arm64: zynqmp: Do not duplicate flash partition label property
    - arm64: zynqmp: Fix serial compatible string
    - ARM: dts: NSP: Fix mpcore, mmc node names
    - scsi: lpfc: Fix list_add() corruption in lpfc_drain_txq()
    - arm64: dts: hisilicon: fix arm,sp805 compatible string
    - RDMA/bnxt_re: Check if the vlan is valid before reporting
    - usb: musb: tusb6010: check return value after calling
      platform_get_resource()
    - usb: typec: tipd: Remove WARN_ON in tps6598x_block_read
    - arm64: dts: qcom: msm8998: Fix CPU/L2 idle state latency and residency
    - arm64: dts: freescale: fix arm,sp805 compatible string
    - ASoC: SOF: Intel: hda-dai: fix potential locking issue
    - clk: imx: imx6ul: Move csi_sel mux to correct base register
    - ASoC: nau8824: Add DMI quirk mechanism for active-high jack-detect
    - scsi: advansys: Fix kernel pointer leak
    - firmware_loader: fix pre-allocated buf built-in firmware use
    - ARM: dts: omap: fix gpmc,mux-add-data type
    - usb: host: ohci-tmio: check ...