USN-6388-1: Linux kernel vulnerabilities

19 September 2023

Several security issues were fixed in the Linux kernel.

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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

Daniel Moghimi discovered that some Intel(R) Processors did not properly
clear microarchitectural state after speculative execution of various
instructions. A local unprivileged user could use this to obtain to
sensitive information. (CVE-2022-40982)

Yang Lan discovered that the GFS2 file system implementation in the Linux
kernel could attempt to dereference a null pointer in some situations. An
attacker could use this to construct a malicious GFS2 image that, when
mounted and operated on, could cause a denial of service (system crash).
(CVE-2023-3212)

It was discovered that the NET/ROM protocol implementation in the Linux
kernel contained a race condition in some situations, 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-2023-32269)

It was discovered that the NFC implementation in the Linux kernel contained
a use-after-free vulnerability when performing peer-to-peer communication
in certain conditions. A privileged attacker could use this to cause a
denial of service (system crash) or possibly expose sensitive information
(kernel memory). (CVE-2023-3863)

It was discovered that the bluetooth subsystem in the Linux kernel did not
properly handle L2CAP socket release, 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-2023-40283)

It was discovered that some network classifier implementations in the Linux
kernel contained use-after-free vulnerabilities. A local attacker could use
this to cause a denial of service (system crash) or possibly execute
arbitrary code. (CVE-2023-4128)

It was discovered that the JFS file system implementation in the Linux
kernel did not properly validate memory allocations in certain situations,
leading to a null pointer dereference vulnerability. An attacker could use
this to construct a malicious JFS image that, when mounted, could cause a
denial of service (system crash). (CVE-2023-4385)

It was discovered that the VMware VMXNET3 ethernet driver in the Linux
kernel contained a use-after-free vulnerability in certain situations. A
local attacker in a guest VM could use this to cause a denial of service
(system crash) or possibly execute arbitrary code. (CVE-2023-4387)

It was discovered that the VMware VMXNET3 ethernet driver in the Linux
kernel did not properly handle errors in certain situations, leading to a
null pointer dereference vulnerability. A local attacker in a guest VM
could use this to cause a denial of service (system crash). (CVE-2023-4459)

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 16.04
Ubuntu 14.04

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.

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