1. Ubuntu Security Notices
  2. USN-4576-1

USN-4576-1: Linux kernel vulnerabilities

Publication date

14 October 2020

Overview

Several security issues were fixed in the Linux kernel.

Releases

Packages

Details

Hadar Manor discovered that the DCCP protocol implementation in the Linux
kernel improperly handled socket reuse, leading to a use-after-free
vulnerability. A local attacker could use this to cause a denial of service
(system crash) or possibly execute arbitrary code. (CVE-2020-16119)

Jay Shin discovered that the ext4 file system implementation in the Linux
kernel did not properly handle directory access with broken indexing,
leading to an out-of-bounds read vulnerability. A local attacker could use
this to cause a denial of service (system crash). (CVE-2020-14314)

David Alan Gilbert discovered that the XFS file system implementation in
the Linux kernel did not properly perform metadata validation in some
circumstances. A local attacker could use this to cause a denial of
service. (CVE-2020-14385)

Giuseppe...

Hadar Manor discovered that the DCCP protocol implementation in the Linux
kernel improperly handled socket reuse, leading to a use-after-free
vulnerability. A local attacker could use this to cause a denial of service
(system crash) or possibly execute arbitrary code. (CVE-2020-16119)

Jay Shin discovered that the ext4 file system implementation in the Linux
kernel did not properly handle directory access with broken indexing,
leading to an out-of-bounds read vulnerability. A local attacker could use
this to cause a denial of service (system crash). (CVE-2020-14314)

David Alan Gilbert discovered that the XFS file system implementation in
the Linux kernel did not properly perform metadata validation in some
circumstances. A local attacker could use this to cause a denial of
service. (CVE-2020-14385)

Giuseppe Scrivano discovered that the overlay file system in the Linux
kernel did not properly perform permission checks in some situations. A
local attacker could possibly use this to bypass intended restrictions and
gain read access to restricted files. (CVE-2020-16120)

It was discovered that a race condition existed in the hugetlb sysctl
implementation in the Linux kernel. A privileged attacker could use this to
cause a denial of service (system crash). (CVE-2020-25285)

It was discovered that the block layer subsystem in the Linux kernel did
not properly handle zero-length requests. A local attacker could use this
to cause a denial of service. (CVE-2020-25641)

Update instructions

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

Learn more about how to get the fixes.

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.

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

Ubuntu Release Package Version
20.04 focal linux-image-5.4.0-1021-raspi –  5.4.0-1021.24
linux-image-5.4.0-1026-kvm –  5.4.0-1026.27
linux-image-5.4.0-1028-aws –  5.4.0-1028.29
linux-image-5.4.0-1028-gcp –  5.4.0-1028.29
linux-image-5.4.0-1028-oracle –  5.4.0-1028.29
linux-image-5.4.0-1031-azure –  5.4.0-1031.32
linux-image-5.4.0-51-generic –  5.4.0-51.56
linux-image-5.4.0-51-generic-lpae –  5.4.0-51.56
linux-image-5.4.0-51-lowlatency –  5.4.0-51.56
linux-image-aws –  5.4.0.1028.29
linux-image-azure –  5.4.0.1031.29
linux-image-gcp –  5.4.0.1028.36
linux-image-generic –  5.4.0.51.54
linux-image-generic-hwe-20.04 –  5.4.0.51.54
linux-image-generic-lpae –  5.4.0.51.54
linux-image-generic-lpae-hwe-20.04 –  5.4.0.51.54
linux-image-gke –  5.4.0.1028.36
linux-image-kvm –  5.4.0.1026.24
linux-image-lowlatency –  5.4.0.51.54
linux-image-lowlatency-hwe-20.04 –  5.4.0.51.54
linux-image-oem –  5.4.0.51.54
linux-image-oem-osp1 –  5.4.0.51.54
linux-image-oracle –  5.4.0.1028.25
linux-image-raspi –  5.4.0.1021.56
linux-image-raspi2 –  5.4.0.1021.56
linux-image-virtual –  5.4.0.51.54
linux-image-virtual-hwe-20.04 –  5.4.0.51.54
18.04 bionic linux-image-5.4.0-1021-raspi –  5.4.0-1021.24~18.04.1
linux-image-5.4.0-1028-aws –  5.4.0-1028.29~18.04.1
linux-image-5.4.0-1028-gcp –  5.4.0-1028.29~18.04.1
linux-image-5.4.0-1028-oracle –  5.4.0-1028.29~18.04.1
linux-image-5.4.0-1031-azure –  5.4.0-1031.32~18.04.1
linux-image-5.4.0-51-generic –  5.4.0-51.56~18.04.1
linux-image-5.4.0-51-generic-lpae –  5.4.0-51.56~18.04.1
linux-image-5.4.0-51-lowlatency –  5.4.0-51.56~18.04.1
linux-image-aws –  5.4.0.1028.13
linux-image-azure –  5.4.0.1031.13
linux-image-gcp –  5.4.0.1028.16
linux-image-generic-hwe-18.04 –  5.4.0.51.56~18.04.45
linux-image-generic-lpae-hwe-18.04 –  5.4.0.51.56~18.04.45
linux-image-lowlatency-hwe-18.04 –  5.4.0.51.56~18.04.45
linux-image-oracle –  5.4.0.1028.12
linux-image-raspi-hwe-18.04 –  5.4.0.1021.25
linux-image-snapdragon-hwe-18.04 –  5.4.0.51.56~18.04.45
linux-image-virtual-hwe-18.04 –  5.4.0.51.56~18.04.45

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References

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