Explore top 10 tips to secure your open-source projects now. Read More

×
Alerts This Week
Warning Icon 1 433
Alerts This Week
Warning Icon 1 433

Ubuntu 20.04 LTS USN-4712-1 High: Kernel Access Denial Issue

ubuntu
Calendar Grey January 28, 2021
Dist Ubuntu Esm H88
Ubuntu addresses Linux kernel issues by upgrading specific software packages to improve overall system reliability and efficiency.
USN-4576-1 introduced a regression in the Linux kernel.

Summary

USN-4576-1 introduced a regression in the Linux kernel.

Software Description:

- linux: Linux kernel

Details:

USN-4576-1 fixed a vulnerability in the overlay file system

implementation in the Linux kernel. Unfortunately, that fix introduced

a regression that could incorrectly deny access to overlay files in

some situations. This update fixes the problem.

We apologize for the inconvenience.

Original vulnerability details:

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.

Topics%20covered

Topics Covered

security advisory high severity software update security fix access issue Ubuntu ubuntu Linux kernel linux kernel kernel regression

Update Instructions

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

Ubuntu 20.10:
  linux-image-5.8.0-41-generic    5.8.0-41.46
  linux-image-5.8.0-41-generic-64k  5.8.0-41.46
  linux-image-5.8.0-41-generic-lpae  5.8.0-41.46
  linux-image-5.8.0-41-lowlatency  5.8.0-41.46
  linux-image-generic             5.8.0.41.45
  linux-image-generic-64k         5.8.0.41.45
  linux-image-generic-lpae        5.8.0.41.45
  linux-image-lowlatency          5.8.0.41.45
  linux-image-oem-20.04           5.8.0.41.45
  linux-image-virtual             5.8.0.41.45

Ubuntu 20.04 LTS:
  linux-image-5.4.0-65-generic    5.4.0-65.73
  linux-image-5.4.0-65-generic-lpae  5.4.0-65.73
  linux-image-5.4.0-65-lowlatency  5.4.0-65.73
  linux-image-generic             5.4.0.65.68
  linux-image-generic-lpae        5.4.0.65.68
  linux-image-lowlatency          5.4.0.65.68
  linux-image-oem                 5.4.0.65.68
  linux-image-oem-osp1            5.4.0.65.68
  linux-image-virtual             5.4.0.65.68

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

https://ubuntu.com/security/notices/USN-4712-1

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1900141, https://ubuntu.com/security/notices/USN-4576-1

January 28, 2021

Topics%20covered

Topics Covered

security advisory high severity software update security fix access issue Ubuntu ubuntu Linux kernel linux kernel kernel regression

Package Information

https://launchpad.net/ubuntu/+source/linux/5.8.0-41.46
https://launchpad.net/ubuntu/+source/linux/5.4.0-65.73

Get the latest News and Insights

Get the latest Linux and open source security news straight to your inbox.