1. Ubuntu Security Notices
  2. USN-4907-1

USN-4907-1: Linux kernel vulnerabilities

Publication date

13 April 2021

Overview

Several security issues were fixed in the Linux kernel.

Releases

Packages

Details

Wen Xu discovered that the xfs file system implementation in the Linux
kernel did not properly validate the number of extents in an inode. An
attacker could use this to construct a malicious xfs image that, when
mounted, could cause a denial of service (system crash). (CVE-2018-13095)

It was discovered that the priority inheritance futex implementation in the
Linux kernel contained a race condition, 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-2021-3347)

It was discovered that the network block device (nbd) driver in the Linux
kernel contained a use-after-free vulnerability during device setup. A
local attacker with access to the nbd device could use this to cause a
denial of service (system crash) or possibly execute arbitrary code.
(

Wen Xu discovered that the xfs file system implementation in the Linux
kernel did not properly validate the number of extents in an inode. An
attacker could use this to construct a malicious xfs image that, when
mounted, could cause a denial of service (system crash). (CVE-2018-13095)

It was discovered that the priority inheritance futex implementation in the
Linux kernel contained a race condition, 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-2021-3347)

It was discovered that the network block device (nbd) driver in the Linux
kernel contained a use-after-free vulnerability during device setup. A
local attacker with access to the nbd device could use this to cause a
denial of service (system crash) or possibly execute arbitrary code.
(CVE-2021-3348)

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
18.04 bionic linux-image-4.15.0-1016-dell300x –  4.15.0-1016.20
linux-image-4.15.0-1069-oracle –  4.15.0-1069.77
linux-image-4.15.0-1083-raspi2 –  4.15.0-1083.88
linux-image-4.15.0-1089-kvm –  4.15.0-1089.91
linux-image-4.15.0-1097-gcp –  4.15.0-1097.110
linux-image-4.15.0-1098-aws –  4.15.0-1098.105
linux-image-4.15.0-1100-snapdragon –  4.15.0-1100.109
linux-image-4.15.0-1112-azure –  4.15.0-1112.125
linux-image-4.15.0-141-generic –  4.15.0-141.145
linux-image-4.15.0-141-generic-lpae –  4.15.0-141.145
linux-image-4.15.0-141-lowlatency –  4.15.0-141.145
linux-image-aws-lts-18.04 –  4.15.0.1098.101
linux-image-azure-lts-18.04 –  4.15.0.1112.85
linux-image-dell300x –  4.15.0.1016.18
linux-image-gcp-lts-18.04 –  4.15.0.1097.115
linux-image-generic –  4.15.0.141.128
linux-image-generic-lpae –  4.15.0.141.128
linux-image-kvm –  4.15.0.1089.85
linux-image-lowlatency –  4.15.0.141.128
linux-image-oracle-lts-18.04 –  4.15.0.1069.79
linux-image-raspi2 –  4.15.0.1083.80
linux-image-snapdragon –  4.15.0.1100.103
linux-image-virtual –  4.15.0.141.128
16.04 xenial linux-image-4.15.0-1069-oracle –  4.15.0-1069.77~16.04.1
linux-image-4.15.0-1097-gcp –  4.15.0-1097.110~16.04.1
linux-image-4.15.0-1098-aws –  4.15.0-1098.105~16.04.1
linux-image-4.15.0-1112-azure –  4.15.0-1112.124~16.04.1
linux-image-aws-hwe –  4.15.0.1098.91
linux-image-azure –  4.15.0.1112.103
linux-image-gcp –  4.15.0.1097.98
linux-image-gke –  4.15.0.1097.98
linux-image-oracle –  4.15.0.1069.57
14.04 trusty linux-image-4.15.0-1112-azure –  4.15.0-1112.124~14.04.1
linux-image-azure –  4.15.0.1112.85

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References

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