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===========================================================================
             AUSCERT External Security Bulletin Redistribution

                              ESB-2020.2562.2
                 USN-4439-1: Linux kernel vulnerabilities
                               31 July 2020

===========================================================================

        AusCERT Security Bulletin Summary
        ---------------------------------

Product:           kernel
Publisher:         Ubuntu
Operating System:  Ubuntu
Impact/Access:     Root Compromise        -- Existing Account      
                   Access Privileged Data -- Existing Account      
                   Denial of Service      -- Remote/Unauthenticated
                   Reduced Security       -- Existing Account      
Resolution:        Patch/Upgrade
CVE Names:         CVE-2020-15780 CVE-2020-13974 CVE-2020-11935
                   CVE-2020-10768 CVE-2020-10767 CVE-2020-10766
                   CVE-2020-10757 CVE-2020-10732 CVE-2019-20908
                   CVE-2019-20810 CVE-2019-19462 CVE-2019-19036
                   CVE-2019-16089 CVE-2019-12380 

Reference:         ESB-2020.2532
                   ESB-2020.2507
                   ESB-2019.3913
                   ESB-2019.2593

Original Bulletin: 
   https://usn.ubuntu.com/4439-1/
   https://usn.ubuntu.com/4440-1/

Revision History:  July 31 2020: USN-4440-1: Additional packages added
                   July 28 2020: Initial Release

- --------------------------BEGIN INCLUDED TEXT--------------------

USN-4439-1: Linux kernel vulnerabilities
27 July 2020

Several security issues were fixed in the Linux kernel.
Releases

  o Ubuntu 18.04 LTS

Packages

  o linux-gke-5.0 - Linux kernel for Google Container Engine (GKE) systems
  o linux-oem-osp1 - Linux kernel for OEM systems

Details

It was discovered that the network block device (nbd) implementation in the
Linux kernel did not properly check for error conditions in some
situations. An attacker could possibly use this to cause a denial of
service (system crash). (CVE-2019-16089)

It was discovered that the btrfs file system implementation in the Linux
kernel did not properly validate file system metadata in some situations.
An attacker could use this to construct a malicious btrfs image that, when
mounted, could cause a denial of service (system crash). (CVE-2019-19036)

It was discovered that the kernel->user space relay implementation in the
Linux kernel did not properly check return values in some situations. A
local attacker could possibly use this to cause a denial of service (system
crash). (CVE-2019-19462)

Chuhong Yuan discovered that go7007 USB audio device driver in the Linux
kernel did not properly deallocate memory in some failure conditions. A
physically proximate attacker could use this to cause a denial of service
(memory exhaustion). (CVE-2019-20810)

It was discovered that the elf handling code in the Linux kernel did not
initialize memory before using it in certain situations. A local attacker
could use this to possibly expose sensitive information (kernel memory).
(CVE-2020-10732)

Fan Yang discovered that the mremap implementation in the Linux kernel did
not properly handle DAX Huge Pages. A local attacker with access to DAX
storage could use this to gain administrative privileges. (CVE-2020-10757)

It was discovered that the Linux kernel did not correctly apply Speculative
Store Bypass Disable (SSBD) mitigations in certain situations. A local
attacker could possibly use this to expose sensitive information.
(CVE-2020-10766)

It was discovered that the Linux kernel did not correctly apply Indirect
Branch Predictor Barrier (IBPB) mitigations in certain situations. A local
attacker could possibly use this to expose sensitive information.
(CVE-2020-10767)

It was discovered that the Linux kernel could incorrectly enable indirect
branch speculation after it has been disabled for a process via a prctl()
call. A local attacker could possibly use this to expose sensitive
information. (CVE-2020-10768)

Mauricio Faria de Oliveira discovered that the aufs implementation in the
Linux kernel improperly managed inode reference counts in the
vfsub_dentry_open() method. A local attacker could use this vulnerability
to cause a denial of service. (CVE-2020-11935)

It was discovered that the Virtual Terminal keyboard driver in the Linux
kernel contained an integer overflow. A local attacker could possibly use
this to have an unspecified impact. (CVE-2020-13974)

It was discovered that the efi subsystem in the Linux kernel did not handle
memory allocation failures during early boot in some situations. A local
attacker could possibly use this to cause a denial of service (system
crash). (CVE-2019-12380)

Jason A. Donenfeld discovered that the ACPI implementation in the Linux
kernel did not properly restrict loading SSDT code from an EFI variable.
A privileged attacker could use this to bypass Secure Boot lockdown
restrictions and execute arbitrary code in the kernel. (CVE-2019-20908)

Jason A. Donenfeld discovered that the ACPI implementation in the Linux
kernel did not properly restrict loading ACPI tables via configfs. A
privileged attacker could use this to bypass Secure Boot lockdown
restrictions and execute arbitrary code in the kernel. (CVE-2020-15780)

Update instructions

The problem can be corrected by updating your system to the following package
versions:

Ubuntu 18.04

  o linux-image-5.0.0-1045-gke - 5.0.0-1045.46
  o linux-image-5.0.0-1065-oem-osp1 - 5.0.0-1065.70
  o linux-image-gke-5.0 - 5.0.0.1045.30
  o linux-image-oem-osp1 - 5.0.0.1065.63

After a standard system update you need to reboot your computer to make
all the necessary changes.

ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.

References

  o CVE-2019-12380
  o CVE-2019-16089
  o CVE-2019-19036
  o CVE-2019-19462
  o CVE-2019-20810
  o CVE-2020-10732
  o CVE-2020-10757
  o CVE-2020-10766
  o CVE-2020-10767
  o CVE-2020-10768
  o CVE-2020-11935
  o CVE-2020-13974
  o CVE-2020-15780
  o CVE-2019-20908

- --------------------------------------------------------------------------------

USN-4440-1: linux kernel vulnerabilities
31 July 2020

Several security issues were fixed in the Linux kernel.
Releases

  o Ubuntu 18.04 LTS

Packages

  o linux-aws-5.3 - Linux kernel for Amazon Web Services (AWS) systems
  o linux-azure-5.3 - Linux kernel for microsoft azure cloud systems
  o linux-gcp-5.3 - Linux kernel for Google Cloud Platform (GCP) systems
  o linux-gke-5.3 - Linux kernel for Google Container Engine (GKE) systems
  o linux-hwe - Linux hardware enablement (HWE) kernel
  o linux-oracle-5.3 - Linux kernel for Oracle Cloud systems
  o linux-raspi2-5.3 - Linux kernel for Raspberry Pi (V7) systems

Details

It was discovered that the network block device (nbd) implementation in the
Linux kernel did not properly check for error conditions in some
situations. An attacker could possibly use this to cause a denial of
service (system crash). (CVE-2019-16089)

It was discovered that the kernel->user space relay implementation in the
Linux kernel did not properly check return values in some situations. A
local attacker could possibly use this to cause a denial of service (system
crash). (CVE-2019-19462)

Chuhong Yuan discovered that go7007 USB audio device driver in the Linux
kernel did not properly deallocate memory in some failure conditions. A
physically proximate attacker could use this to cause a denial of service
(memory exhaustion). (CVE-2019-20810)

Jason A. Donenfeld discovered that the ACPI implementation in the Linux
kernel did not properly restrict loading SSDT code from an EFI variable. A
privileged attacker could use this to bypass Secure Boot lockdown
restrictions and execute arbitrary code in the kernel. (CVE-2019-20908)

It was discovered that the elf handling code in the Linux kernel did not
initialize memory before using it in certain situations. A local attacker
could use this to possibly expose sensitive information (kernel memory).
(CVE-2020-10732)

Fan Yang discovered that the mremap implementation in the Linux kernel did
not properly handle DAX Huge Pages. A local attacker with access to DAX
storage could use this to gain administrative privileges. (CVE-2020-10757)

It was discovered that the Linux kernel did not correctly apply Speculative
Store Bypass Disable (SSBD) mitigations in certain situations. A local
attacker could possibly use this to expose sensitive information.
(CVE-2020-10766)

It was discovered that the Linux kernel did not correctly apply Indirect
Branch Predictor Barrier (IBPB) mitigations in certain situations. A local
attacker could possibly use this to expose sensitive information.
(CVE-2020-10767)

It was discovered that the Linux kernel could incorrectly enable indirect
branch speculation after it has been disabled for a process via a prctl()
call. A local attacker could possibly use this to expose sensitive
information. (CVE-2020-10768)

Mauricio Faria de Oliveira discovered that the aufs implementation in the
Linux kernel improperly managed inode reference counts in the
vfsub_dentry_open() method. A local attacker could use this vulnerability
to cause a denial of service. (CVE-2020-11935)

It was discovered that the Virtual Terminal keyboard driver in the Linux
kernel contained an integer overflow. A local attacker could possibly use
this to have an unspecified impact. (CVE-2020-13974)

Jason A. Donenfeld discovered that the ACPI implementation in the Linux
kernel did not properly restrict loading ACPI tables via configfs. A
privileged attacker could use this to bypass Secure Boot lockdown
restrictions and execute arbitrary code in the kernel. (CVE-2020-15780)

Update instructions

The problem can be corrected by updating your system to the following package
versions:

Ubuntu 18.04

  o linux-image-5.3.0-1030-oracle - 5.3.0-1030.32~18.04.1
  o linux-image-5.3.0-1030-raspi2 - 5.3.0-1030.32~18.04.2
  o linux-image-5.3.0-1032-aws - 5.3.0-1032.34~18.04.2
  o linux-image-5.3.0-1032-gcp - 5.3.0-1032.34~18.04.1
  o linux-image-5.3.0-1032-gke - 5.3.0-1032.34~18.04.1
  o linux-image-5.3.0-1034-azure - 5.3.0-1034.35~18.04.1
  o linux-image-5.3.0-64-generic - 5.3.0-64.58~18.04.1
  o linux-image-5.3.0-64-generic-lpae - 5.3.0-64.58~18.04.1
  o linux-image-5.3.0-64-lowlatency - 5.3.0-64.58~18.04.1
  o linux-image-aws - 5.3.0.1032.31
  o linux-image-azure - 5.3.0.1034.30
  o linux-image-gcp - 5.3.0.1032.26
  o linux-image-gke-5.3 - 5.3.0.1032.17
  o linux-image-gkeop-5.3 - 5.3.0.64.120
  o linux-image-oracle - 5.3.0.1030.27
  o linux-image-raspi2-hwe-18.04 - 5.3.0.1030.20

After a standard system update you need to reboot your computer to make
all the necessary changes.

ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.

References

  o CVE-2019-16089
  o CVE-2019-19462
  o CVE-2019-20810
  o CVE-2019-20908
  o CVE-2020-10732
  o CVE-2020-10757
  o CVE-2020-10766
  o CVE-2020-10767
  o CVE-2020-10768
  o CVE-2020-11935
  o CVE-2020-13974
  o CVE-2020-15780

- --------------------------END INCLUDED TEXT--------------------

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