USN-6072-1: Linux kernel (OEM) vulnerabilities

10 May 2023

Several security issues were fixed in the Linux kernel.

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Releases

Packages

Details

It was discovered that the Traffic-Control Index (TCINDEX) implementation
in the Linux kernel did not properly perform filter deactivation in some
situations. A local attacker could possibly use this to gain elevated
privileges. Please note that with the fix for this CVE, kernel support for
the TCINDEX classifier has been removed. (CVE-2023-1829)

Lin Ma discovered a race condition in the io_uring subsystem in the Linux
kernel, leading to a null pointer dereference vulnerability. A local
attacker could use this to cause a denial of service (system crash).
(CVE-2023-0468)

It was discovered that the OverlayFS implementation in the Linux kernel did
not properly handle copy up operation in some conditions. A local attacker
could possibly use this to gain elevated privileges. (CVE-2023-0386)

It was discovered that a race condition existed in the Xen transport layer
implementation for the 9P file system protocol in the Linux kernel, leading
to a use-after-free vulnerability. A local attacker could use this to cause
a denial of service (guest crash) or expose sensitive information (guest
kernel memory). (CVE-2023-1859)

Kyle Zeng discovered that the ATM VC queuing discipline implementation in
the Linux kernel contained a type confusion vulnerability in some
situations. An attacker could use this to cause a denial of service (system
crash). (CVE-2023-23455)

Lianhui Tang discovered that the MPLS implementation in the Linux kernel
did not properly handle certain sysctl allocation failure conditions,
leading to a double-free vulnerability. An attacker could use this to cause
a denial of service or possibly execute arbitrary code. (CVE-2023-26545)

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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 22.04

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.