USN-5319-1: Linux kernel vulnerabilities

9 March 2022

Several security issues were fixed in the Linux kernel.

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Releases

Packages

Details

Enrico Barberis, Pietro Frigo, Marius Muench, Herbert Bos, and Cristiano
Giuffrida discovered that hardware mitigations added by Intel to their
processors to address Spectre-BTI were insufficient. A local attacker could
potentially use this to expose sensitive information.

Reduce your security exposure

Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.

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Update instructions

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

Ubuntu 18.04
Ubuntu 16.04
Ubuntu 14.04

IMPORTANT: As part of this update, unprivileged eBPF is being
disabled by default, as it is the primary known means of exploiting
the Branch History Injection issues described above. It should be
noted that other mechanisms for exploiting the underlying issues may
be discovered. Also, this may cause issues for applications that
rely on the unprivileged eBPF functionality. Please see the knowledge
base article at https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/BHI
for more details.

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

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