1. Ubuntu Security Notices
  2. USN-5211-1

USN-5211-1: Linux kernel vulnerability

Publication date

6 January 2022

Overview

The system could be made to crash or run programs as an administrator.

Releases

Packages

  • linux - Linux kernel
  • linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  • linux-kvm - Linux kernel for cloud environments
  • linux-lts-xenial - Linux hardware enablement kernel from Xenial for Trusty

Details

Nadav Amit discovered that the hugetlb implementation in the Linux kernel
did not perform TLB flushes under certain conditions. A local attacker
could use this to leak or alter data from other processes that use huge
pages.

Nadav Amit discovered that the hugetlb implementation in the Linux kernel
did not perform TLB flushes under certain conditions. A local attacker
could use this to leak or alter data from other processes that use huge
pages.

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
16.04 xenial linux-image-4.4.0-1099-kvm –  4.4.0-1099.108  
linux-image-4.4.0-1134-aws –  4.4.0-1134.148  
linux-image-4.4.0-218-generic –  4.4.0-218.251  
linux-image-4.4.0-218-lowlatency –  4.4.0-218.251  
linux-image-aws –  4.4.0.1134.139  
linux-image-generic –  4.4.0.218.225  
linux-image-kvm –  4.4.0.1099.97  
linux-image-lowlatency –  4.4.0.218.225  
linux-image-virtual –  4.4.0.218.225  
14.04 trusty linux-image-3.13.0-189-generic –  3.13.0-189.240  
linux-image-3.13.0-189-generic-lpae –  3.13.0-189.240  
linux-image-3.13.0-189-lowlatency –  3.13.0-189.240  
linux-image-4.4.0-1098-aws –  4.4.0-1098.103  
linux-image-4.4.0-218-generic –  4.4.0-218.251~14.04.1  
linux-image-4.4.0-218-lowlatency –  4.4.0-218.251~14.04.1  
linux-image-aws –  4.4.0.1098.96  
linux-image-generic –  3.13.0.189.198  
linux-image-generic-lpae –  3.13.0.189.198  
linux-image-generic-lts-xenial –  4.4.0.218.189  
linux-image-lowlatency –  3.13.0.189.198  
linux-image-lowlatency-lts-xenial –  4.4.0.218.189  
linux-image-server –  3.13.0.189.198  
linux-image-virtual –  3.13.0.189.198  
linux-image-virtual-lts-xenial –  4.4.0.218.189  

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References

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